In all cases, the heat shield appeared in excellent condition and the Mission Management Team formally cleared Atlantis for entry. The crew was packing up for a landing Wednesday at the Kennedy Space Center when the MMT decided to delay entry for 24 hours.
The shuttle has enough supplies on board to stay in orbit until Saturday and more than enough fuel to re-rendezvous with the space station if necessary. Assuming the issue turns out to be benign, the forecast for Thursday and Friday in Florida is excellent, with the first of two Thursday opportunities on tap at 6:22 a.m. Thursday.
10:15 a.m., 09/19/06, Update: Shuttle TV antenna stow delayed to give ground controllers time to look for unusual object seen earlier below shuttle
Flight controllers spotted an unusual object below the space shuttle Atlantis earlier today in video downlinked from the orbiter. Not sure what it might be, controllers asked the crew to delay stowing the ship's KU-band television antenna and teardown of the crew's laptop computer network to permit engineers to continue looking for the object while the astronauts sleep.
The object was spotted by a flight controller who was operating the shuttle's payload bay cameras around 2:45 a.m., a NASA spokeswoman said. Videotape replayed just before 10 a.m. showed what appeared to be a small object below the shuttle flying at roughly the same speed and in the same direction.
"INCO had seen an object in the video during Earth observations and we just want to keep the KU up and possibly downlink more video here in the near term," astronaut Terry Virts called from mission control in Houston. "We're looking at keeping it up overnight."
"Ok, that makes sense. Just let us know what you want to do," an Atlantis astronaut replied. "And you don't need OCA router for all that, right? We can go ahead and tear that down?"
"We'd actually like to keep the whole PGSC network up," Virts replied.
No other details were immediately available. Shuttle program manager Wayne Hale may discuss the matter, however, at a previously planned Mission Management Team briefing at 12 p.m.
09:30 a.m., 09/19/06, Update: Weather front poses challenge for Wednesday landing; outlook good Thursday and Friday
An approaching front is expected to bring high winds and possible thunder showers to Florida's Space Coast early Wednesday, threatening NASA's plans to bring the shuttle Atlantis back to Earth after a successful space station construction mission.
The Atlantis astronauts have two Florida landing opportunities Wednesday on successive orbits, at 5:59 a.m. and 7:34 a.m.:
http://www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts115/mission_docs/landing.html
Entry flight director Steve Stich said if the weather doesn't cooperate, the astronauts will remain in orbit an additional day and make another attempt to get back to the Kennedy Space Center on Thursday.
The shuttle has enough on-board supplies to stay in space until Saturday, but the forecast for Thursday and Friday calls for good weather.
"The weather outlook for tomorrow is not as promising as I would like," Stich told reporters today. "The front that came through the Houston area Sunday and yesterday will be in the Kennedy Space Center area on landing day. So our forecast is for crosswinds out of limits on our first rev, which is a night opportunity, and also some showers within 30 miles and the possibility of some low ceilings. So we'll have to deal with that.
"The weather forecasters tell me they think the front will be through there right around the time between these two deorbit opportunities. So we'll watch the weather very carefully and if it's a good day to land we'll do so and if the weather doesn't meet our criteria, we'll have to go around again and try to land Thursday at the Kennedy Space Center. The forecast for Thursday and Friday calls for light winds and no threatening showers. Stich said that could change if the front stalls over Florida, but assuming it keeps moving as forecasters expect, NASA's strategy will be to make landing attempts in Florida only Wednesday and Thursday before activating the agency's backup landing site at Edwards Air Force Base, Calif., for attempts Friday, on one coast or the other, if needed.
The first landing opportunity Wednesday calls for a deorbit rocket firing, on orbit 170, at 4:52:08 a.m. and a pre-sunrise landing at 5:59:19 a.m. after an approach up the east coast of Florida. The forecast calls for a possible broken cloud deck at 5,000 feet, a chance of thundershowers within 30 nautical miles and crosswinds peaking at 15 knots. The crosswind limit for a pre-dawn landing is 12 knots.
The second landing opportunity calls for a deorbit rocket firing one orbit later at 6:27:02 a.m. and a landing at 7:33:39 a.m. The forecast remains roughly the same, but the crosswind limit goes up to 15 knots for a daylight landing.
"There are rain showers and thunderstorms out in front of the front and so basically whether Wednesday is a good opportunity or not is going to depend on the front passage," astronaut Tony Antonelli radioed the crew from mission control in Houston.
"The models have the front passing between the two revs. We'll take a look at it when we come in tomorrow and see. We're going to try to be smart with the timeline. If it looks like we have a chance, we're going to press all the way through deorbit prep. If it looks early like we don't have a chance, then we'll try to knock it off early so we don't waste your efforts."
"OK, Tony, we appreciate the information," Atlantis commander Brent Jett replied. "Obviously, we're ready to do whatever you guys need and we'll be ready to go tomorrow if the weather's good."
Here's a timeline of re-entry activities for both Wednesday landing opportunities (in EDT; includes final approach and docking of the Soyuz TMA-9 spacecraft at the international space station):
TIME/EDT ORBIT 170 OPPORTUNITY TO KSC _________________________________________________________________ 12:30:00 AM (NASA TV coverage of Soyuz docking begins) 12:37:00 AM Mission control weather briefing 12:52:00 AM Begin deorbit timeline 01:04:00 AM (Soyuz fly-around of space station begins) 01:07:00 AM Radiator stow 01:15:00 AM (Soyuz final approach begins) 01:17:00 AM Mission specialists seat installation 01:23:00 AM Computers set for deorbit prep 01:24:00 AM (Soyuz TMA-9 docks with space station) 01:27:00 AM Hydraulic system configuration 01:40:00 AM Post-docking news conference at Russian control center 01:52:00 AM Flash evaporator cooling system checkout 02:07:00 AM Mission control "go" for payload bay door closing 02:12:00 AM Payload bay doors closed 02:22:00 AM Mission control 'go' for OPS-3 entry software load 02:32:00 AM OPS-3 transition 02:57:00 AM Entry switch list verification 03:07:00 AM Deorbit rocket firing update 03:12:00 AM Crew entry review 03:27:00 AM Jett/Ferguson don entry suits 03:44:00 AM Navigation unit alignment 03:52:00 AM Jett/Ferguson strap in; other crew members don suits 04:09:00 AM Shuttle steering check 04:10:00 AM (NASA coverage of Soyuz hatch opening begins) 04:12:00 AM Hydraulic power unit prestart 04:19:00 AM Toilet deactivation 04:27:00 AM Vent doors closed for entry 04;30:00 AM (Russian TV coverage of Soyuz hatch opening) 04:32:00 AM Mission control 'go' for deorbit burn 04:38:00 AM Astronauts strap in 04:43:00 AM (End of Russian TV coverage of Soyuz activities) 04:47:00 AM Single hydraulic power unit start 04:48:00 AM TDRS-West comsat acquisition of signal 04:52:08 AM Deorbit ignition 04:54:52 AM Deorbit burn complete 05:27:42 AM Altitude 400,000 feet; shuttle in discernible atmosphere 05:32:12 AM (STS-107: EI+4:30 - 1st unusual data) 05:32:40 AM 1st roll command to left 05:43:38 AM (STS-107: EI+15:56 - Last valid data) 05:47:41 AM 1st left-to-right roll reversal 05:52:45 AM Velocity less than Mach 2.5 05:54:58 AM Velocity less than Mach 1 05:56:09 AM Shuttle banks around heading alignment cylinder 05:59:19 AM Landing on runway 15 TIME/EDT ORBIT 171 OPPORTUNITY TO KSC _________________________________________________________________ 06:07:00 AM MCC 'go' for deorbit burn 06:13:00 AM Astronaut seat ingress 06:22:00 AM Single hydraulic power unit start 06:27:02 AM Deorbit ignition 06:29:47 AM Deorbit burn complete 07:02:02 AM Altitude 400,000 feet 07:06:32 AM (STS-107: EI+4:30 - 1st unusual data) 07:06:56 AM 1st roll command to left 07:16:30 AM 1st left-to-right roll reversal 07:17:58 AM (STS-107: EI+15:56 - Last valid data) 07:27:07 AM Velocity less than Mach 2.5 07:29:18 AM Velocity less than Mach 1 07:29:53 AM Shuttle on the heading alignment cylinder 07:33:39 AM Landing on runway 33If the weather doesn't cooperate, the astronauts will have multiple landing opportunities Thursday and Friday at the Kennedy Space Center, Edwards Air Force Base and Northrup Strip near White Sands, N.M., if worst comes to worst. Here are all the possible landing opportunities through Saturday (all times in EDT):
DATE ORBIT D/O BURN LANDING SITE 09/20 170 04:52 AM 05:59 AM Kennedy Space Center 09/20 171 06:27 AM 07:34 AM KSC 09/21 186 05:14 AM 06:22 AM KSC 09/21 187 06:46 AM 07:54 AM Northrup Strip 09/21 187 06:50 AM 07:57 AM KSC 09/21 188 08:20 AM 09:27 AM Edwards Air Force Base 09/21 188 08:22 AM 09:29 AM NOR 09/21 189 09:56 AM 11:03 AM EDW 09/22 201 04:02 AM 05:10 AM KSC 09/22 202 05:37 AM 06:45 AM KSC 09/22 203 07:07 AM 08:15 AM EDW 09/22 203 07:09 AM 08:16 AM NOR 09/22 204 08:43 AM 09:50 AM EDW 09/22 204 08:45 AM 09:52 AM NOR 09/22 205 10:19 AM 11:26 AM EDW 09/23 217 04:24 AM 05:32 AM KSC 09/23 218 05:56 AM 07:03 AM NOR 09/23 218 06:00 AM 07:08 AM KSC 09/23 219 07:30 AM 08:37 AM EDW 09/23 219 07:32 AM 08:39 AM NOR 09/23 220 09:06 AM 10:13 AM EDW
03:50 a.m., 09/19/06, Update: Shuttle, station, Soyuz crews enjoy complex conference call
The 12 men and women currently off the planet got a chance to chat this morning, thanks to a long-distance conference call connecting the space shuttle Atlantis, the international space station and a Russian Soyuz capsule carrying a space tourist and the station's next crew.
The call took place just after 3 a.m., as the Soyuz TMA-9 spacecraft, carrying Expedition 14 commander Mike Lopez-Alegria, Mikhail "Misha" Tyurin and space tourist Anousheh Ansari sailed across Russia while the shuttle and space station, separated by about 98 miles, were passing 220 miles above Australia.
"Good to hear your voice, Misha," station flight engineer Jeff Williams called. "And good morning Mike and Anousheh. It's a little crowded in the sky this morning with not only Atlantis and you all and us, but also the Progress free flier."
Late Monday, Russian flight controllers sent commands to the space station to undock a Progress supply ship, loaded with trash and no-longer-needed equipment. It burned up in the atmosphere as planned a few hours later, clearing the way for arrival of the Soyuz Wednesday.
"We were wondering if we had to hire some more air traffic controllers for the increased traffic up here," joked Lopez-Alegria.
"We'll just have to keep eyeballs out a little more than usual," Williams replied. "How's your flight been going, Mike?"
"Everything has been (Russian phrase)," Lopez-Alegria said. The Soyuz blasted off from the Baikonur Cosmodrome in Kazakhstan early Sunday and if all goes well, Tyurin will guide it to a docking with the space station at 1:24 a.m. Wednesday.
"Hello Misha, Mike and Anousheh," called station flight engineer Thomas Reiter. "Good to hear your voices!"
"Hello everyone," said Ansari, who is believed to have paid in the neighborhood of $20 million for the trip. "I look forward to seeing you on the station."
"In just a few hours, you will be here," Reiter said.
"Yes," she said.
"Yeah, we look forward to welcoming you all on board," Williams said. "Atlantis, do you want to step in here and say hello?"
"Yeah, 14, how do you hear Atlantis?" shuttle commander Brent Jett called.
"Brent, we have you loud and clear. How us?" asked Lopez-Alegria.
"Loud and clear also, LA," Jett said. "Joe (Tanner) just mentioned three hogs in space and I think you have a tactical advantage right now in terms of fighter position."
Jett was referring to an astronaut class mascot and the fact that the Soyuz was trailing the space station and Atlantis by about 6,550 miles, catching up to the lab complex in a lower, faster orbit.
"Well, you guys are probably sorry to be heading home," Lopez-Alegria said, "but it'll be nice to have a cold beer and a shower."
"It's been real short for us, you know," Jett said. "It's kind of funny, you guys are just starting a really long journey in space and our very short one is quickly coming to an end, sooner than we would like."
After a short drop out, Lopez-Alegria asked Jett about landing preparations.
"Yeah, entry day, our first opportunity's tomorrow, the weather's not looking all that good for tomorrow at KSC (Kennedy Space Center) but it's supposed to be real good the next day. So we may end up getting an extra day on orbit, which would not be all bad."
"Just make sure you save some good food," Lopez-Alegria joked.
"Actually, they gave all the food to us to save for you," Williams chimed in.
"They cleaned us out pretty good, looking out for you guys," Jett confirmed.
"Misha says as long as there's (unintelligible) he'll be happy."
"I think you guys will be happy with the supplies on board, we're well supplied with two shuttle visits and a Progress," Williams said.
"Hey Mike, before you go, Jeff and Pavel and Thomas, they've taken great care of station, it's really in great shape," Jett said. "We were really impressed, they've done a fantastic job. This mission would not have been a success without them. They were an integral part of it. So you're going to be impressed when you get there and I know you guys are going to have a good time."
"We know we have a lot to learn from all of them and we look forward to our time together, especially having Anousheh on board," said Lopez-Alegria. "It's too bad that the Atlantis crew won't get to meet her, maybe at some opportunity on the ground in the future. But I think she should have a great short stay aboard and we look forward (to seeing the rest of you)."
"And we look forward to getting you guys on board," Williams replied. "We're going to get up bright and early, or dark and early, however you want to say it, tomorrow morning and bring out the welcome mat."
By docking time, the Soyuz crew should have its space legs. Tyurin told Russian flight controllers late Monday that Lopez-Alegria and Ansari were experiencing at least some of the symptoms of space adaptation syndrome, which affects about half the men and women who fly in weightlessness.
As the conference call was breaking up, a Russian controller called the Soyuz to say a flight surgeon was standing by to chat with Ansari. But she sounded in good spirits when she hailed the space station.
02:15 a.m., 09/19/06, Update: Astronauts pack up, test re-entry systems
The Atlantis astronauts tested the shuttle's re-entry systems today and began packing up for a Florida landing Wednesday, weather permitting, to close out a successful space station assembly mission.
Flight controllers in Houston and Moscow, meanwhile, had their hands full tracking Atlantis, the space station and the Soyuz TMA-9 spacecraft launched early Monday from Kazakhstan carrying the station's next commander, a fresh flight engineer and a space tourist.
Giving new meaning to the phrase "long distance," controllers worked to set up a 3 a.m. conference call between Atlantis, the station and the Soyuz to give all 12 astronauts and cosmonauts - six on the shuttle, three on the station and three on the Soyuz - a chance to chat for a few moments as they raced through space at five miles per second.
The Soyuz TMA-9 capsule, carrying Expedition 14 commander Mike Lopez-Alegria, flight engineer and Soyuz commander Mikhail Tyurin and space tourist Anousheh Ansari, is closing in on the space station for a planned docking Wednesday at 1:24 a.m. The linkup will come about four-and-a-half hours before Atlantis' planned 5:59 a.m. landing at the Kennedy Space Center.
If all goes well, Expedition 13 commander Pavel Vinogradov, flight engineer Jeff Williams and Ansari will return to Earth Sept. 28 aboard the Soyuz TMA-8 spacecraft that carried the two station crewmen into space last spring. Expedition 13 flight engineer Thomas Reiter, who was carried to the station aboard the shuttle Discovery in July, will remain aboard the outpost as a member of the Expedition 14 crew. Aboard Atlantis today, commander Brent Jett, pilot Chris Ferguson and flight engineer Dan Burbank checked out the shuttle's re-entry systems, powering up one of the ship's three hydraulic power units before test firing a battery of maneuvering jets. Later this morning, the two pilots will take turns practicing landing procedures using a computer simulator before a final round of media interviews beginning at 5:30 a.m. The astronauts will enjoy two hours of off-duty time after their midday meal before breaking down their laptop computer network, storing an exercise machine and stowing the ship's KU-band antenna.
Here is an updated timeline of today's activities (in EDT and mission elapsed time):
TIME/EDT DD HH MM EVENT 12:30 AM 09 13 15 Cabin stow begins 01:20 AM 09 14 05 Flight control system checkout 02:30 AM 09 15 15 Reaction control system hotfire 03:00 AM 09 15 45 Shuttle-station-Soyuz audio call 04:00 AM 09 16 45 Simulator landing practice for Jett, Ferguson 05:00 AM 09 17 45 Deorbit review 05:30 AM 09 18 15 Media interviews with shuttle astronauts 05:50 AM 09 18 35 Crew meal 06:50 AM 09 19 35 Crew off duty time begins 08:00 AM 09 20 45 Mission status briefing on NASA TV 08:50 AM 09 21 35 Cabin stow resumes 09:00 AM 09 21 45 Entry video setup 10:20 AM 09 23 05 Laptop computer teardown (part 1) 10:30 AM 09 23 15 Ergometer stow 11:00 AM 09 23 45 Ku-band antenna stow 12:00 PM 10 00 45 Post-Mission Management Team status briefing 01:00 Pm 10 01 45 Video file on NASA TV 01:45 PM 10 02 30 Crew sleep begins 06:00 PM 10 06 45 Daily video highlights reel 09:45 PM 10 10 30 Crew wakeupFor readers interested in a look ahead to landing day, an updated entry events timeline is now posted listing all major activities for two landing opportunities Wednesday at the Kennedy Space Center.
A forecast released Monday calls for possible thundershowers within 30 nautical miles of the shuttle's runway Wednesday morning and crosswinds gusting to 15 knots, right at NASA's safety limit. The outlook for Thursday and Friday includes only a slight chance of showers and light winds.
Atlantis has enough on-board supplies to remain in orbit until Saturday if absolutely necessary. Entry flight director Steve Stich will outline his landing strategy later today, but given the forecast he's unlikely to activate NASA's backup landing site at Edwards Air Force Base, Calif., until Thursday or Friday.
Here are all four Florida landing opportunities for Wednesday and Thursday (in EDT and mission elapsed time):
DATE/EDT DD HH MM EVENT 09/20/06 04:52 AM 10 17 37 Deorbit ignition (orbit 170) 05:59 AM 10 18 44 1st KSC landing opportunity 06:27 AM 10 19 12 Backup deorbit ignition (orbit 171) 07:34 AM 10 20 19 2nd KSC landing opportunity 01:45 PM 11 02 30 Crew sleep (if waveoff) 09:45 PM 11 10 30 Crew wakeup 09/21/06 05:19 AM 11 18 04 Backup deorbit ignition (orbit 186) 06:21 AM 11 19 06 3rd KSC landing opportunity 06:55 AM 11 19 40 Backup deorbit ignition (orbit 187) 07:57 AM 11 20 42 4th KSC landing opportunity
03:30 a.m., 09/18/06, Update: Atlantis astronauts carry out final heat shield inspection
The Atlantis astronauts carried out a final inspection of the shuttle's heat shield today, using a laser on the end of a long boom to look for signs of damage on the ship's nose cap and wing leading edge panels.
An identical inspection was carried out Sept. 10, the day after launch, to make sure the most critical parts of the heat shield came through the climb to space in good condition. Today's inspection was designed to make sure no space debris or micrometeoroids hit the shuttle unnoticed while docked with the international space station.
"The first one is obviously geared towards any debris which came off during ascent and may have hit the orbiter," commander Brent Jett said in a NASA interview. "ThereÕs a second threat to your thermal protection system, and that is from micrometeorite damage. ItÕs a threat we deal with on every mission."
Heat shield inspections are carried out using a 50-foot-long boom attached to the end of the shuttle's 50-foot-long robot arm. A laser scanner and a high-resolution camera are mounted on the end of the orbiter boom sensor system to look for signs of damage to the reinforced carbon carbon material making up the shuttle's nose cap and wing leading edge panels. Those areas experience the most extreme heating during re-entry, some 3,000 degrees Fahrenheit.
"ThereÕs an analysis done that gives you the probability of being struck by a micrometeorite," Jett said. "It all depends on what attitude youÕre flying and what orbit youÕre flying in. The thought is that if you inspect early in the mission for ascent debris, you might want to inspect late in the mission to see if youÕve sustained any damage from a micrometeorite hit on the RCC, a critical area of the orbiter."
Along with carrying out the heat shield inspection, Jett and his crewmates - pilot Chris Ferguson, flight engineer Dan Burbank, Joe Tanner, Canadian Steve MacLean and Heidemarie Stefanyshyn-Piper - also plan to begin initial packing for re-entry and landing Wednesday. Cabin stow will begin in earnest Tuesday, when the astronauts also will test the shuttle's re-entry systems.
Here is an updated timeline of today's activity (in EDT and mission elapsed time):
TIME/EDT DD HH MM EVENT 02:20 AM 08 15 05 Orbiter boom sensor system (OBSS) unberth 03:25 AM 08 16 10 OBSS starboard wing leading edge survey 04:15 AM 08 17 00 Cabin stow begins 04:55 AM 08 17 40 OBSS nose cap survey 06:25 AM 08 19 10 Crew meal 07:25 AM 08 20 10 OBSS port wing leading edge survey 08:00 AM 08 20 45 Mission status briefing on NASA TV 08:55 AM 08 21 40 OBSS berthing 09:30 AM 08 22 15 Robot arm berthing and powerdown 10:15 AM 08 23 00 Laser dynamic range imager downlink 01:20 PM 09 02 05 NC-7 rocket firing 02:15 PM 09 03 00 Crew sleep begins 03:00 PM 09 03 45 Daily video highlights reel on NASA TV 08:28 PM 09 09 13 Progress cargo ship undocks from ISS 10:15 PM 09 11 00 Crew wakeupAtlantis undocked from the space station early Sunday to make way for arrival of the lab's next commander and flight engineer, Mike Lopez-Alegria and cosmonaut Mikhail Tyurin. The Expedition 14 crew members, along with space tourist Anousheh Ansari, blasted off from the Baikonur Cosmodrome in Kazakhstan at 12:09 a.m. EDT today aboard the Soyuz TMA-9 spacecraft.
If all goes well, they will dock with the station at 1:24 a.m. Wednesday, just a few hours before Atlantis is scheduled to land at the Kennedy Space Center.
Ansari will return to Earth on Sept. 28 with the station's outgoing crew, Expedition 13 commander Pavel Vinogradov and flight engineer Jeff Williams. European Space Agency astronaut Thomas Reiter, ferried to the station aboard the shuttle Discovery in July, will remain aboard the outpost as part of the Expedition 14 crew until December, when he will return to Earth with the crew of the next shuttle assembly mission.
01:00 p.m., 09/17/06, Update: Atlantis undocks from space station; fly-around video thrills NASA managers; adding quotes from mission status briefing, Soyuz TMA-9 pre-launch briefing
The shuttle Atlantis undocked from the international space station today, beaming down spectacular video of the lab complex and clearing the way for launch of the station's next full-time crew early Monday to kick off the 14th long-duration expedition.
"In the next three days on station, they'll be having a shuttle undock, a Progress (supply ship) undock, a shuttle land and us dock," Expedition 14 commander Mike Lopez-Alegria said at a pre-flight news conference at the Baikonur Cosmodrome in Kazakhstan.
"It's a consequence of the complexity of the task that we're trying to undertake that as you need more air traffic controllers when the airport gets busier, that's the situation that we're facing. I frankly think it's very exciting. I think it bodes well for our future and I think we all look forward to the era of the construction of the station."
Atlantis undocked from the space station at 8:50 a.m., about 15 hours before the scheduled launch of the Soyuz TMA-9 spacecraft at 12:09 a.m. EDT Monday. The shuttle flew a slow loop around the station for photo documentation, the first 360-degree fly around in the post-Columbia era.
Dramatic video showed the station's new solar arrays gleaming against the blue and white backdrop of planet Earth as the two spacecraft streaked 220 miles above the heartland of America, the Great Lakes and the St. Lawrence Seaway at 5 miles per second.
The station had a distinctly asymmetrical look with the newly added 240-foot-long P4 solar arrays arrays positioned at right angles to the lab's other major set of solar panels, known as P6.
P6 provided power for the early stages of station assembly in a temporary position on a truss atop the multi-hatch Unity module that connects the U.S. and Russian segments of the lab. Next year, if all goes well, P6 will be moved to its permanent position adjacent to the P4 arrays on the left end of the station's main power truss.
"Hey Jeff, we completed the fly-around," shuttle commander Brent Jett called as the shuttle began moving away. "I just wanted to let you know we got a lot of great pictures, it was really a spectacular sight to see your vehicle from above, looking down on the Earth. So hopefully, we'll get to send some of those to you over the next couple of days and we'll see you back on Earth in a little while."
"Yeah, we'll look forward to seeing those," station flight engineer Jeff Williams replied from the lab complex. "I think we got some pretty good pictures and video of you guys in the fly around as well, especially underneath with the Earth in the background. So those pictures will be on the ground when you get there, waiting for you. It was a great mission, thanks for all the good work, enjoyed the time together and look forward to seeing you back in Houston."
"Yeah, we really appreciate it," Jett replied, "it was fun working with you guys. Be safe the rest of your mission."
"You bet. So long now."
At the sprawling Baikonur Cosmodrome, meanwhile, Russian rocket engineers were preparing the Soyuz TMA-9 spacecraft for launch. Monday night, a Progress supply ship loaded with trash and no-longer-needed equipment will undock from the Russian Zvezda command module's aft port, clearing the way for Lopez-Alegria, cosmonaut Mikhail Tyurin and space tourist Anousheh Ansari to dock at 1:24 a.m Wednesday.
Four-and-a-half-hours later, Atlantis is scheduled for landing at the Kennedy Space Center.
Ansari will return to Earth Sept. 28 with Expedition 13 commander Pavel Vinogradov and flight engineer Jeff Williams. European Space Agency astronaut Thomas Reiter, who flew to the station aboard the shuttle Discovery in July, will remain aboard the lab complex as a member of the Expedition 14 crew until late December.
Ansari, born in Iran and a naturalized U.S. citizen, is the fourth private citizen to buy a seat on a Soyuz for a trip to the international space station. She helped sponsor the $10 million Ansari X-Prize competition for development of sub-orbital space flight and while she would not disclose the actual cost of her space station trip, it is believed to be in the neighborhood of $20 million.
Lopez-Alegria, asked if space tourism was a good idea, told a reporter "if you would have asked me that question a couple of years ago, I might have answered quite differently because I was sort of a critic of space tourism." He added that "sending people to the international space station while it was still under construction was still by no means a place for the light hearted."
"But I recognize the requirements that the Russian space agency has to keep its program alive, we can't do what we're doing without them, so if that's what the correct solution is, and if somebody like Anousheh can be that person, then I have come to the realization that not only is it good from a technical standpoint, just to keep the program going, but it's also good from the standpoint that she represents a great dream and a great hope for a lot of people, not just in our country and iran, but all over the world. I think it was short sighted of me, perhaps, to think the way I did a couple of years ago so I'm somewhat of a convert."
Tyurin agreed, saying it was time for spaceflight to move beyond government-only sponsorship. As for Ansari's presence on the crew, "I was sincerely surprised when we started working together by the high level of professionalism she has even though she's not a professional cosmonaut. She became such a natural part of our crew we have the impression we've been working together for maybe 10 years."
Ansari, wearing a blue flight suit sporting a personally designed mission patch, pointed out that she would be taking off in a Soyuz spacecraft that is very similar to Russian capsules launched at the dawn of the space age.
"It's been over 45 years since the first human flew to space and over these 45 years, only government agencies have been working toward the goal of space exploration," Ansari said. "In order for us to make giant leaps toward space exploration ... we need private industry to get involved and help the government agencies and work collaboratively together to be able to make that lofty goal come true in the near future for us.
"So I'm hoping to be an ambassador to take this message out and get more people interested and more private investment made into space exploration," she said. "I also want to add that taking an orbital flight is not an easy task. ... It does require a lot of training, you have to be mentally and physically prepared for it, you have to get to know the system that you're flying because there's a lot of dangers out there. It definitely requires a lot of training and it's not necessarily for the light of heart."
Ansari plans to describe her experiences throughout the flight in a blog hosted by the X-Prize Foundation: http://spaceblog.xprize.org/2006/09/17/the-day-has-come/ Atlantis was launched Sept. 9 and docked with the station last Monday. Over the next five days, Jett, pilot Chris Ferguson, Dan Burbank, Joe Tanner, Canadian Steve MacLean and Heidemarie Stefanyshyn-Piper installed the new arrays, wired them into the station's power grid, and activated a massive rotary joint that will drive the panels like huge waterwheels to track the sun as the station circles the globe.
The P4 and P6 solar panels stretch 240 feet from tip to tip. The new P4 arrays currently are locked in place because of interference with the left wing of the P6 array. That wing will be retracted in December in preparation for moving P6 to the main truss next August.
Between now and December, the P4 arrays will remain stationary and canted at slightly different angles to prevent rocket plume contamination from the shuttle on the front end and Soyuz/Progress arrivals and departures on the back end.
Over the next half-dozen flights, considered the most complex in manned spaceflight history, shuttle crews will build out the solar array truss, re-wire the station's power system, activate complex ammonia coolant loops and prepare the station for arrival of European and Japanese research modules.
Given the success of Atlantis' mission, Phil Engelauf, a senior manager at the Johnson Space Center in Houston, said flight planners, engineers and managers are optimistic about the work ahead.
But not overly confident.
"You feel confident in the sense that you've got one tough hurdle behind you," he said today. "But that doesn't really change the equation for the outlying flights. I think everybody at NASA involved in this program has commented about the difficulty of this sequence of flights, how each one of them really has to go well in order for the whole sequence to work.
"We now have one of those under our belt and that certainly a good feeling. (But) there are a lot of difficult milestones ahead and we're far from finished. We're one lap down, but it's a long race."
With hugs and handshakes, the Atlantis astronauts bid farewell to their space station colleagues today, signed the lab's logbook and closed hatches between the two spacecraft.
"Houston, the log book has been completed, all of the ceremonies have taken place and the STS-115 crew is egressing the station for the final time," Jett radioed as the farewell ceremony broke up.
Williams, following naval tradition, then rang the ship's bell and called out: "STS-115, the crew of Atlantis departing" as the shuttle astronauts left the Destiny laboratory module and floated back into the orbiter.
The shuttle's hatch was closed at 6:27 a.m. and the vestibule between the hatch and the station was depressurized.
With Ferguson at the controls, Atlantis' docking system was disengaged on time at 8:50 a.m. and powerful springs pushed the shuttle, tail toward Earth and cargo bay facing the station, straight away along the direction of travel.
After reaching a point roughly 400 feet directly ahead of the station, Ferguson guided the spaceplane though a 360-degree loop around the lab complex, passing 600 feet directly above, behind, below and back out directly in front again before leaving the area for good.
The astronauts plan to carry out a final heat shield inspection Monday before packing up and testing the shuttle's re-entry systems Tuesday. Landing at the Kennedy Space Center is targeted for 5:58 a.m. Wednesday.
10:30 a.m., 09/17/06, Update: Atlantis completes station fly around; bids station crew farewell
Shuttle pilot Chris Ferguson piloted Atlantis through a slow, looping fly around of the international space station today, beaming back spectacular video of the orbital lab complex with its new solar arrays gleaming against the blue-and-white backdrop of planet Earth.
It was the first 360-degree shuttle-station fly around of the post-Columbia era and the first since 2002 to show the station with a significant new addition: the P3/P4 solar array truss carried aloft and installed by Atlantis' crew.
Streaking through space at 5 miles per second 220 miles above the heartland of America, the Great Lakes and the St. Lawrence Seaway, the new array gave the outpost a distinctly asymmetrical look, positioned at right angles to its other major set of solar panels, the P6 array.
P6 provided power for the early stages of station assembly in a temporary position atop a truss on the Unity module. Next year, if all goes well, it will be moved to its permanent position adjacent to the P4 arrays on the left end of the station's main power truss.
"Hey Jeff, we completed the fly-around," shuttle commander Brent Jett called as the shuttle began moving away. "I just wanted to let you know we got a lot of great pictures, it was really a spectacular sight to see your vehicle from above, looking down on the Earth. So hopefully, we'll get to send some of those to you over the next couple of days and we'll see you back on Earth in a little while."
"Yeah, we'll look forward to seeing those," station flight engineer Jeff Williams replied from the lab complex. "I think we got some pretty good pictures and video of you guys in the fly around as well, especially underneath with the Earth in the background. So those pictures will be on the ground when you get there, waiting for you. It was a great mission, thanks for all the good work, enjoyed the time together and look forward to seeing you back in Houston."
"Yeah, we really appreciate it," Jett replied, "it was fun working with you guys. Be safe the rest of your mission."
"You bet. So long now."
08:55 a.m., 09/17/06, Update: Atlantis undocks from space station
The shuttle Atlantis undocked from the international space station today, closing out a successful visit to attach a new set of solar arrays and clearing the way for launch of a Russian Soyuz spacecraft early Monday carrying the lab's next commander, a fresh flight engineer and a space tourist.
With pilot Chris Ferguson at the controls, Atlantis' docking system was disengaged on time at 8:50 a.m. and powerful springs pushed the shuttle, tail toward Earth and cargo bay facing the station, straight away as the two spacecraft sailed 220 miles above the Pacific Ocean southeast of Australia.
After reaching a point roughly 400 feet directly ahead of the station, the flight plan called for Ferguson to guide the shuttle though a 360-degree loop around the lab complex, passing directly above, behind, below and back out directly in front again before leaving the area for good.
07:15 a.m., 09/17/06, Update: Crew farewells; station/shuttle hatches closed
With hugs and handshakes, the Atlantis astronauts bid farewell to their space station colleagues today, signed the lab's logbook and closed hatches between the two spacecraft, setting the stage for undocking at 8:50 a.m.
"Houston, the log book has been completed, all of the ceremonies have taken place and the STS-115 crew is egressing the station for the final time," shuttle commander Brent Jett radioed as the farewell ceremony broke up.
Station flight engineer Jeff Williams, following naval tradition, rang the ship's bell and called out: "STS-115, the crew of Atlantis departing" as the shuttle astronauts left the Destiny laboratory module and floated back into the orbiter.
The shuttle's hatch was closed at 6:27 a.m. and the vestibule between the hatch and the station was depressurized. See the 4 a.m. status report for a detailed timeline.
04:00 a.m., 09/17/06, Update: Atlantis astronauts prepare for undocking
The Atlantis astronauts are rigging the shuttle for undocking from the international space station this morning. A final joint meal with the station crew is planned for 5 a.m. with a farewell ceremony and hatch closing on tap at 6 a.m. and 6:24 a.m. respectively.
With shuttle pilot Chris Ferguson at the controls, Atlantis is scheduled to undock from pressurized mating adapter No. 2 on the front of the Destiny laboratory module at 8:50 a.m. Ferguson will guide the shuttle to a point about 400 feet directly in front of the lab complex before beginning a 360-degree fly around for photo documentation.
"We're really looking forward to the fly-around, seeing the station in a new configuration," said lead flight director Paul Dye. "I just think itÕs going to be gorgeous. The views I've seen already - you know, the beautiful gold arrays, and the Earth in the background - itÕs going to be real nice."
Passing 600 feet directly above, behind and below the space station, Ferguson will guide Atlantis back to a point directly in front of the outpost and carry out the first of two rocket firings at 10:05 a.m. to begin the shuttle's final separation.
This will be the first complete space station fly around since the Columbia disaster and engineers are looking forward to getting a good look at the lab complex and its new set of solar arrays.
"It wasn't a real high priority, but it's certainly nice to have and I think we should get some pretty spectacular video of the station," Dye said. "And that helps everybody, because if you have any questions about the external configuration, you can go back and look for it."
A second separation burn is scheduled for 10:33 a.m. Atlantis will drop back to a point about 40 nautical miles behind the space station where it will remain through Monday when the crew plans to carry out a final heat shield inspection.
At the sprawling Baikonur Cosmodrome in Kazakhstan, meanwhile, Russian rocket engineers are preparing the Soyuz TMA-9 spacecraft for launch at 12:09 a.m. Monday to ferry the station's next full-time crew to the international outpost.
If all goes well, Expedition 14 commander Mike Lopez-Alegria, cosmonaut Mikhail Tyurin and space tourist Anousheh Ansari will dock at the aft port of the Russian Zvezda command module at 1:24 a.m Wednesday, about four-and-a-half-hours before Atlantis is scheduled for landing at the Kennedy Space Center.
NASA television coverage of the Soyuz TMA-9 launch begins at 11:30 p.m. Ansari will return to Earth Sept. 28 with Expedition 13 commander Pavel Vinogradov and flight engineer Jeff Williams. European Space Agency astronaut Thomas Reiter, who flew to the station aboard the shuttle Discovery in July, will remain aboard the lab complex as a member of the Expedition 14 crew until late December.
Here is an updated timeline of today's activities that combines the NASA television schedule (rev. N), the crew's summary flight plan and the detailed undocking timeline (in EDT and mission elapsed time):
TIME/EDT DD HH MM EVENT 12:15 AM 07 13 00 STS/ISS crew wakeup 02:35 AM 07 15 20 Transfers resume 03:35 AM 07 16 20 Rendezvous tools checkout 04:15 AM 07 17 00 Oxygen transfer hardware tear down 04:35 AM 07 17 20 Transfer tagup 05:00 AM 07 17 45 Joint crew meal 06:00 AM 07 18 45 Farewell ceremony 06:24 AM 07 19 09 Hatch closure 06:45 AM 07 19 30 Centerline camera installation 06:45 AM 07 19 30 Orbiter docking system leak check 07:30 AM 07 20 15 Spacesuit installation 07:30 AM 07 20 15 Group B computer powerup 07:36 AM 07 20 21 Sunrise 07:45 AM 07 20 30 ISS maneuver to undocking attitude 08:00 AM 07 20 45 Shuttle undocking timeline begins 08:07 AM 07 20 52 Noon 08:30 AM 07 21 15 P6 solar arrays feathered 08:37 AM 07 21 22 U.S. feathering complete 08:36 AM 07 21 21 Sunset 08:50 AM 07 21 35 Atlantis undocks from space station 08:51 AM 07 21 36 Initial orbiter separation (+10 seconds) 08:52 AM 07 21 37 ISS holds current attitude 08:55 AM 07 21 40 Range: 50 feet; reselect -X jets 08:57 AM 07 21 42 Range: 75 feet; low-Z jets 09:00 AM 07 21 45 Russian arrays resume tracking 09:05 AM 07 21 50 Range: 170 feet 09:08 AM 07 21 53 Sunrise 09:19 AM 07 22 04 Range: 400 feet; start flyaround 09:29 AM 07 22 14 Range: 600 feet 09:30 AM 07 22 15 P6 arrays resume tracking 09:30 AM 07 22 15 ISS maneuvers (+YVV) 09:31 AM 07 22 16 Atlantis directly above ISS 09:38 AM 07 22 23 Noon 09:42 AM 07 22 27 Atlantis directly behind ISS 09:54 AM 07 22 39 Atlantis directly below ISS 10:05 AM 07 22 50 Atlantis directly in front of ISS 10:05 AM 07 22 50 Separation burn No. 1 10:08 AM 07 22 53 Sunset 10:30 AM 07 23 15 PMA-2 depressurization 10:33 AM 07 23 18 Separation burn No. 2 10:35 AM 07 23 20 Group B computer powerdown 10:39 AM 07 23 24 Sunrise 11:00 AM 07 23 45 Mission status briefing on NASA TV 11:15 AM 08 00 00 Undocking videotape replay 12:00 PM 08 00 45 ISS-14 pre-launch briefing replay on NASA TV 12:15 PM 08 01 00 NC-5 rocket firing 03:15 PM 08 04 00 STS crew sleep begins 03:45 PM 08 04 30 ISS crew sleep begins 04:00 PM 08 04 45 Daily video highlights reel on NASA TV 10:30 PM 08 11 15 ISS-14 pre-launch b-roll feel on NASA TV 11:15 PM 08 12 00 STS crew wakeup 11:30 PM 08 12 15 ISS-14 launch coverage begins on NASA TV 12:09 AM 08 12 54 ISS-14/Soyuz TMA-9 launch
10:45 a.m., 09/16/06, Update: Veteran spacewalker credits rookies with saving the day on station
The successful attachment and deployment of a huge new set of solar arrays on the international space station "bodes well" for a complex set of upcoming shuttle flights to build out the main power truss and ready the craft for attachment of European and Japanese research modules, Atlantis commander Brent Jett said today.
Atlantis' flight marks the resumption of station assembly after a three-and-a-half-year hiatus and while Jett said he was heartened by his crew's success, every flight must go well for NASA to complete the outpost by the Bush administration's 2010 deadline.
"I think it's certainly a good start," Jett told CBS News in an interview today. "Obviously, we have a lot of complex missions ahead to finish the station by 2010. We needed to get the first one off, we had a few small problems but the team on the ground did a wonderful job resolving them. So I think it bodes well for the future. Plus, the lessons we learned on this mission we can pass on to future missions with similar hardware."
Space station Program Manager Mike Suffredini joked Friday that Jett's crew was so successful his biggest challenge now is convincing people station construction is as difficult as NASA managers and astronauts have been saying.
But Joe Tanner, a four-flight veteran who now ranks fourth in the world for total time spacewalking, said Atlantis' mission might not have gone so well if two rookies - Dan Burbank and Canadian flier Steve MacLean - hadn't gotten a galled bolt out during the crew's second spacewalk.
Asking about Suffredini's joking comment, Tanner said "I want to squash that bug right now. These EVAs were not easy. The fact that everybody said they looked easy is a real compliment to these three other people here and we appreciate it. Thank you very much."
Floating on Atlantis' aft flight deck by Burbank, MacLean and his own partner, Heidemarie Stefanyshyn-Piper, Tanner then reached down and pulled up a giant wrench.
"I know these two guys, these big, strong guys, aren't going to brag on themselves, so I want to show you the tool that they used on EVA-2," Tanner said. "This is a ratchet wrench with a nine-inch rigid extension and a cheater bar to give yourself a little more leverage. The moment arm here is around two feet and these guys backed out a bolt that was sticky, they're estimating it was probably 130 to 140 foot pounds of torque. They basically cut some new threads in a pretty sizable bolt. That was not in any shape or form easy.
"If we hadn't gotten that bolt out, the arrays would not have been able to deploy and we'd be scratching our heads right now trying to figure out how to get that bolt out. So thanks for telling us we made it look easy, but it certainly was not."
Atlantis blasted off Sept. 9, one day after a fuel tank hydrogen sensor malfunctioned and forced a 24-hour delay. NASA managers considered launching Atlantis that same day, despite a flight rule that calls for a 24-hour stand down in that situation. In the end, launch was scrubbed during a final hold at the T-minus nine-minute mark.
Jett said today he agreed with the decision to stand down in accordance with the applicable launch commit criteria, or LCC. But he didn't mind taking the countdown into the final hold while the issue was discussed.
"When we left for the pad, we sort of expected that we were not going to launch," he said. "We knew what the LCC rule was, it was written very clearly. We write those rules ahead of time so when we get into a situation with launch pressure, or maybe a little bit of launch fever, we can go to the rules and (know) we've debated all that rationale in a calmer environment.
"We were ready to go, obviously, but we expected to go out and at some point scrub in the launch. But we felt it was a very worthwhile exercise because we know it was good to check out as many of the systems on the vehicle, take the count as far as you can, to try to discover any potential issues for that launch attempt on Saturday."
Jett, Tanner, Burbank, Piper, MacLean and pilot Chris Ferguson enjoyed a half-day off earlier today. Sunday morning, Atlantis is scheduled to undock from the space station and, after a one-and-a-quarter-loop fly-around for a photo survey of the lab complex, back away to a point about 40 nautical miles away.
On Monday, the crew will carry out a second inspection of the shuttle's nose cap and wing leading edge panels, which experience the most extreme heating during re-entry, to make sure no space debris or micrometeoroids hit the craft after a similar inspection the day after launch.
Assuming no problems are found, the astronauts will pack up Tuesday and test the shuttle's re-entry systems before heading back to the Kennedy Space Center Wednesday morning.
Touchdown is targeted for 5:57 a.m., but high crosswinds and possible thundershowers could cause problems. Atlantis has enough on-board supplies, however, to stay in orbit for at least three additional days if necessary. The forecast improves Thursday, with light winds and only a slight chance of showers.
06:00 a.m., 09/16/06, Update: Astronauts enjoy off-duty time; Soyuz moved to launch pad; timeline of upcoming events
The Atlantis astronauts, the major tasks of their space station assembly mission behind them, took a half-day off Saturday to relax and enjoy the view from 220 miles up.
The combined space station and shuttle crews will enjoy a joint meal later this morning before participating in a news conference and network television interviews.
Here is an updated timeline of the crew's activities (in EDT and mission elasped time):
TIME/EDT DD HH MM EVENT 12:15 AM 06 13 00 STS/ISS crew wakeup 03:15 AM 06 16 00 STS crew off duty time begins 07:15 AM 06 20 00 Joint crew meal 08:15 AM 06 21 00 Joint crew photo 08:35 AM 06 21 20 Joint crew news conference 09:10 AM 06 21 55 Speed brake 09:15 AM 06 22 00 REBA removal 09:35 AM 06 22 20 CBS/NBC/ABC network interviews 09:50 AM 06 22 35 Transfers continue 09:50 AM 06 22 35 EVA prep for shuttle transfer 10:00 AM 06 22 15 Mission status briefing on NASA TV 10:30 AM 06 23 15 News conference replay on NASA TV 12:00 PM 06 00 45 ISS-14 video file on NASA TV 01:25 PM 07 02 10 Transfer tagup 03:45 PM 07 04 30 ISS crew sleep begins 04:15 PM 07 05 00 STS crew sleep begins 05:00 PM 07 05 45 Daily video highlights reel on NASA TVThe next few days will be extremely busy for U.S. and Russian space station managers, with the departure of Atlantis early Sunday, launch of the station's next crew aboard a Russian Soyuz rocket early Monday, undocking of a Progress supply ship Monday night and arrival of the Soyuz on Wednesday.
At the Baikonur Cosmodrome in Kazakhstan late Friday night (U.S. time), the Soyuz TMA-9 spacecraft was rolled to the launch pad and erected for blastoff to ferry Expedition 14 commander Mike Lopez-Alegria, cosmonaut Mikhail Tyurin and space tourist Anousheh Ansari to the space station.
Soyuz TMA-9 is hauled to the launch pad. (Rob Navias/NASA)
Soyuz TMA-9 readied for launch Monday. (Rob Navias/NASA)
Ansari, a businesswoman and space enthusiast who helped fund the Ansari X-Prize competition for sub-orbital spaceflight, is the fourth "space tourist" to buy a seat on a Soyuz and a trip to the space station.
"Everything looks perfect, everything's prepared just right and everyone's excited and ready," she told CBS News Friday.
Ansari was added to the Soyuz crew when a Japanese space tourist was disqualified for medical reasons. Asked about the risk of riding a rocket into space, she said it was the means to realize a life-long dream.
"To me, there are certain things worth taking the risk for," she said by telephone from Baikonur. "I am not a big adventurous person who would take risks just to have an adrenalin rush. So I'm not particularly fond of riding rockets, necessarily, but to me, that's the means for me to get to space, which is my destination.
"The risks involved are what I felt comfortable (with) and the price to pay to be able to realize my dream. It's something that's hard to describe for me. I think space travel is important enough that you can see astronauts and cosmonauts taking risks every day because they believe in it, they believe it's necessary for the future of our species. ... There are people who are the pioneers, people who are moving to take this type of early risk to pave the way for the rest of us. I'm hoping to be one of those people."
Launch is targeted for 12:09 a.m. EDT Monday. The Progress supply ship currently docked at the Zvezda command module's aft port will depart Monday night at 8:28 p.m. EDT, clearing the way for the Soyuz docking at 1:24 a.m. Wednesday.
The station's current crew - Expedition 13 commander Pavel Vinogradov, Jeff Williams and European Space Agency astronaut Thomas Reiter - spent the day today loading the Progress with no-longer-needed equipment and trash.
Vinogradov, Williams and Ansari will strap into the Soyuz TMA-8 spacecraft and undock at 5:54 p.m. EDT Sept. 28 for a landing that night at 9:10 p.m. EDT. Reiter will remain aboard the station as part of the Expedition 14 crew until December, when he will be replaced by astronaut Sunita Williams during the next space shuttle assembly mission.
Here is a timeline of the upcoming station traffic (in EDT):
09/17/06 08:50:00 AM Atlantis undocks from ISS 10:33:00 AM Shuttle departs area after ISS flyaround 12:00:00 PM ISS-14 pre-launch news conference replay on NASA TV 10:30:00 PM Soyuz TMA-9/ISS-14 b-roll footage on NASA TV 11:30:00 PM NASA TV Soyuz TMA-9 launch coverage begins 09/18/06 12:08:40 AM Launch of Soyuz TMA-9/ISS-14 from Baikonur Cosmodrome 02:30:00 AM Post-launch activities on NASA TV 03:25:00 AM Atlantis crew carries out final heat shield inspection 08:28:00 PM Progress M-56 undocking from ISS Zvezda aft port 11:27:00 PM Progress M-56 deorbit ignition (dT: 2:40; dV: 190 mph) 09/19/06 12:03:00 AM Progress M-56 falls into the atmosphere 02:35:00 AM Atlantis crew tests flight control system; cabin stow 09/20/06 01:24:00 AM Soyuz TMA-9 docking with ISS at Zvezda aft port 04:20:00 AM Soyuz TMA-9 hatch open 04:55:00 AM Atlantis deorbit ignition 05:57:00 AM Atlantis lands at the Kennedy Space Center 09/28/06 05:51:00 PM Soyuz TMA-8 undocking command 05:54:00 PM Hooks open, separation 05:57:00 PM Separation burn (dT: 8s; dV: 1.2 mph) 08:20:23 PM Deorbit burn (dT: 4:20; dV: 258 mph) 08:24:43 PM Deorbit burn complete 08:43:57 PM Soyuz module separation 08:46:52 PM Soyuz crew module hits discernible atmosphere 08:53:06 PM Maximum deceleration 08:55:09 PM Parachute open command 09:10:09 PM Landing (17 minutes before sunrise)
01:00 p.m., 09/15/06, Update: Spacewalk No. 3 ends
Astronauts Joe Tanner and Heidemarie Stefanyshyn-Piper began repressurizing space station's Quest airlock today at 12:42 p.m. to officially close out a third and final space station assembly spacewalk.
The spacewalk began at 6 a.m. for a duration of six hours and 42 minutes. Tanner and Piper logged six hours and 26 minutes during a spacewalk Tuesday, giving them a total of 13 hours and eight minutes, while Dan Burbank and Steve MacLean put in seven hours and 11 minutes during an excursion Wednesday.
Total spacewalk time for Atlantis' mission was 20 hours and 19 minutes and Tanner, now a veteran of seven spacewalks, moved up to No. 4 on the world EVA list with a total of nearly 46-and-a-half hours.
"OK, well I guess that's it for me," Tanner said just before re-entering the airlock to close out his final spacewalk.
"Yep, the sun goes down on an era," Piper said. "I should say 'on a legend.'"
"Ah, I don't think so," replied Tanner, veteran of a 1997 Hubble Space Telescope servicing mission and three other station spacewalks in 2000.
A few minutes later, he thanked the spacewalk trainers at the Johnson Space Center for preparing the Atlantis crew for all three EVAs. Astronaut Pam Melroy in mission control credited him with "another legendary performance."
Today's spacealk was the 72nd devoted to space station assembly and maintenance since construction began in December 1998. Forty-five Americans, 13 Russians, two Canadians, one Japanese astronaut and one French flier have now logged 438 hours and 36 minutes of station spacewalk time.
09:10 a.m., 09/15/06, Update: Solar array radiator deployed
With launch restraints removed, flight controllers sent commands to unfold a 44-foot-long radiator panel on the international space station today that will help keep the electronics inside a new solar array module cool once it comes on line.
Television shots from space showed the big radiator, made up of seven hinged panels, unfolding and stretching away from the P4 solar array as the station sailed 218 miles above Saudi Arabia. Dual coolant loops will help control temperatures in the array's integrated electronics assembly, which houses the gear needed to regulate power from the solar panels.
The 1,600-pound radiator is 44 feet long, 12 feet wide and can dissipate up to 14 kilowatts of heat.
Astronauts Joe Tanner and Heidemarie Stefanyshyn-Piper, meanwhile, enjoyed the view from a safe distance away where they were working to upgrade the station's S-band communications gear.
"That's a pretty above-average view I've got right now," Tanner said, looking across the station's main solar array truss and the nose of Atlantis at the blue-and-white Earth below.
"That's the Suez Canal, the Holy Land... wow," Tanner marveled a few moments later. "Wow."
06:05 a.m., 09/15/06, Update: Spacewalk No. 3 begins
Astronauts Joe Tanner (EV-1) and Heidemarie Stefanyshyn-Piper (EV-2), floating inside the Quest airlock module, switched their spacesuits to internal battery power at 6 a.m. to officially begin the third and final planned spacewalk for Atlantis' space station assembly mission.
The spacewalk began 45 minutes late because of time lost troubleshooting the cause of a circuit breaker trip. Here is a revised timeline of today's EVA (times approximate; in EDT and spacewalk elapsed time):
TIME/EDT HH MM EVENT ______________________________________________ 06:00 AM 00 00 Spacesuits to battery power 06:05 AM 00 05 EVA-3: Airlock egress/setup 06:20 AM 00 20 EVA-3: EV1: EVA-P6 BGA clips installation 06:20 AM 00 20 EVA-3: EV2: MISSE 5 retrieval 06:50 AM 00 50 EVA-3: EV2: P4 radiator prep/deploy 07:15 AM 01 15 EVA-3: EV1: P4 radiator prep/deploy 07:40 AM 01 40 EVA-3: P3 cleanup/foot restraint move 08:00 AM 02 00 Radiator deploy 08:10 AM 02 10 EVA-3: S-band antenna support assembly R&R 10:00 AM 04 00 EVA-3: EV2: S-band processor/transponder R&R 10:10 AM 04 10 EVA-3: EV1: KU thermal blanket install 10:30 AM 04 30 EVA-3: EV1: EWIS antenna installation 11:00 AM 05 00 EVA-3: EV2: EWIS antenna installation 11:20 AM 05 20 EVA-3: EV1: Infrared camera DTO 12:00 PM 06 00 EVA-3: Cleanup 12:25 PM 06 25 EVA-3: Airlock repressurization
04:30 a.m., 09/15/06, Update: Spacewalk start time revised
Time lost because of an airlock circuit breaker trip earlier today has put spacewalk preparations about 45 minutes behind schedule. The excursion by astronauts Joe Tanner and Heidemarie Stefanyshyn-Piper is now expected to begin around 6 a.m.
03:30 a.m., 09/15/06, Update: Astronauts prepare for final spacewalk
Astronauts Joe Tanner and Heidemarie Stefanyshyn-Piper are gearing up for a final spacewalk today to close out work on a new solar array truss and upgrade the international space station's communications system. An airlock circuit breaker tripped early today, but engineers did not see any signs of a short and the device was reset without incident.
The goals of today's excursion, scheduled to begin around 5:15 a.m., are to wrap up final work to ready the new P3/P4 solar array truss segments for operation, releasing restraints holding a set of seven folding radiator panels in place on the P4 segment. Extending 44 feet when fully deployed, the radiator's dual ammonia coolant loops will keep the solar arrays internal electronics at the proper temperature once the system goes into operation.
Tanner and Piper also will upgrade the space station's S-band communications system, install a thermal blanket around electronics used by the station's high-speed KU-band antenna and retrieve a space exposure experiment. Finally, they will install a wireless antenna system to collect structural data on the solar array truss and clear a safety tether that ended up draped over the path of the station's mobile transporter after a spacewalk Wednesday.
The mobile transporter is a high-tech cart that creeps along rails along the front side of the solar array truss. It can lock itself down at various work sites to provide a stable work platform for the Canadarm 2 space crane. Later today, flight controllers will send commands to move the transporter from work site 7 to a new work site - WS-8 - on P3 that will be needed in December to attach another truss segment.
Today's spacewalk will be the 72nd devoted to space station assembly and maintenance and the third for the Atlantis astronauts. Tanner and Piper spent six hours and 26 minutes outside Tuesday, wiring in the new P3/P4 truss segments while Dan Burbank and Steve MacLean staged a seven-hour 11-minute spacewalk Wednesday preparing a large solar array drive mechanism for operation. Those two EVAs pushed total spacewalk time on the space station to 431 hours and 54 minutes since assembly began in 1998.
As with the previous two spacewalks, Tanner and Piper spent the night inside the Quest airlock module at a reduced pressure of 10.2 pounds per square inch to help purge nitrogen from their bloodstreams, part of a procedure to ensure they don't suffer the bends working in their 5-psi spacesuits.
Early today, a remote power controller, or RPC, tripped off, taking down power to the airlock module and its depressurization pump, but engineers later determined there had not been a short and decided to reset the device.
"We reset the RPC, we watched the data for a while and then we turned the depress pump back on and it seems to be running just fine now," astronaut Kevin Ford in mission control.
"OK. And this is one of those known conditions, characteristics of RPCs?" asked station astronaut Jeff Williams.
"We don't think it was a nominal kind of thing, Jeff, we did see a little spike in the current of the depress pump," Ford said. "But it definitely did not look like a short."
Tanner's call sign is EV-1 and for identification, his spacesuit features solid red stripes around the legs. Piper is EV-2 and her suit has no markings.
Here is an updated timeline of today's activity (NOTE: the NASA TV schedule is not yet in synch with the revised spacewalk timeline; in EDT and mission elapsed time):
TIME/EDT DD HH MM EVENT _____________________________________________ 12:15 AM 05 13 00 STS/ISS crew wakeup 12:45 AM 05 13 30 EVA-3: Hygiene break/pre-breathe 01:00 AM 05 13 45 EVA-3: Crew lock repress 01:30 AM 05 14 15 EVA-3: Crew lock depress to 10.2 psi 02:05 AM 05 14 50 EVA-3: Campout EVA prep 03:35 AM 05 16 20 EVA-3: Spacesuit purge 03:50 AM 05 16 35 EVA-3: Spacesuit oxygen pre-breathe 04:40 AM 05 17 25 EVA-3: Crew lock depressurization 05:15 AM 05 18 00 ISS: ISS-13 departure preparation 05:15 AM 05 18 00 EVA-3: Airlock egress/setup; spacewalk begins* 05:30 AM 05 18 15 EVA-3: EV1: P6 BGA latch clips install 05:30 AM 05 18 15 EVA-3: EV2: MISSE 5 experiment retrieval 06:00 AM 05 18 45 EVA-3: EV2: P4 radiator prep and deploy 06:25 AM 05 19 10 EVA-3: EV1: P4 radiator prep and deploy 06:50 AM 05 19 35 EVA-3: P3 cleanup (foot restraints moved) 07:20 AM 05 20 05 EVA-3: S-band antenna support assembly R&R 09:10 AM 05 21 55 EVA-3: EV2: S-band signal processor and transponder R&R 09:20 AM 05 22 05 EVA-3: EV1: KU heat shield installation 09:40 AM 05 22 25 EVA-3: EV1: EWIS antenna installation 10:10 AM 05 22 55 EVA-3: EV2: EWIS antenna installation 10:30 AM 05 23 15 EVA-3: EV1: Infrared camera DTO 11:15 AM 06 00 00 EVA-3: Cleanup 11:35 AM 06 00 20 EVA-3: Airlock repressurization 11:50 AM 06 00 35 Post-EVA spacesuit servicing 12:50 PM 06 01 35 Transporter move from WS-7 to WS-8 01:45 PM 06 02 30 BSA init 02:00 PM 06 02 45 Mission status briefing on NASA TV 02:20 PM 06 03 05 WS-8 checkout 02:35 PM 06 03 20 Transporter move from WS-8 to WS-4 on S0 03:00 PM 06 03 45 Video file on NASA TV 03:45 PM 06 04 30 ISS crew sleep begins 04:15 PM 06 05 00 STS crew sleep begin 05:00 PM 06 05 45 Daily video highlights reel on NASA TV *May be impacted by RPC troubleshooting"EVA 3 is a cleanup of P3 primarily, to prepare it for future missions," Tanner said in a NASA interview. "On P4 we have two activities. One to prepare the radiator for deploy, and then loosen some bolts on an MMOD (micrometeoroid orbital debris) cover. That's kind of a get-ahead, but we'll probably do that as well, and then relocate some foot restraints for (the next assembly crew)."
Tanner also will test an infrared camera under development as a diagnostic tool that could help future crews spot damage to the shuttle's wing leading edge panels. It may also prove useful for space station inspections.
"If everything that we have planned right now ends up on the plate for EVA 3, it'll take two-and-a-half or three hours probably, of activity (on the new truss)," Tanner said. "Then we say goodbye to P3/P4 and bring all of our tools back in and our tethers and start to work on changing out some things on S1, some tool boxes and the S-band transponder and a signal processor in the S-band communication system."
"Heide will be working on an electronic instrumentation antenna on the lab and I'll be heading up to the top of P6 to take care of some unfinished business up there from STS-97, on one balky latch up there, and then putting some clips on some bolts and finally bringing down a science experiment known as MISSE-5. I'll be up on the top for 45 minutes or so and Heide and I will really be separated. And then we join back up again and finish up probably a six, six-and--a-half hour EVA and then head back in."
Burbank and MacLean completed some of the tasks originally planned for today during their spacewalk Wednesday, including removal of no-longer-needed hardware to clear the mobile transporter's path from work site 7 to the new work site 8 on the far left end of the solar array truss.
09:15 a.m., 09/14/06, Update: Second solar array deployed
UPDATED at 2:20 p.m. with quotes from news conference; booster cam video
The Atlantis astronauts successfully unfurled a second solar array today, giving the international space station a new set of wings stretching some 240 feet from tip to tip and completing the primary goal of the 116th shuttle mission.
While the mission is far from over - a third spacewalk is on tap Friday - getting the new solar arrays attached and deployed marks a critical first step in the resumption of space station assembly after a three-and-a-half-year hiatus.
"We're happy to be here to tell you the truss, the P3/P4 truss is installed, the SARJ joint's checked out, the solar arrays are deployed, we're in outstanding shape," space station Program Manager Mike Suffredini told reporters. "The bottom line is, this flight has gone better than my wildest dreams."
This afternoon, NASA released spectacular video of Atlantis' launch Sept. 9 that was shot by cameras mounted on the ship's twin solid-fuel boosters and in a WB-57 jet aircraft flying at 60,000 feet near the launch pad.
The booster cams showed no obvious problems with the shuttle's external tank insulation and no signs of any heat shield damage. While the WB-57 footage was not as sharp, it provided dramatic views of the shuttle well after booster separation, including ignition of Atlantis' orbital maneuvering system engines for additional boost.
But deployment of the space station's new solar arrays was the clear highlight of today's activity in space.
The P3/P4 arrays are needed for the next planned assembly mission in December as NASA works through a complex sequence of flights that must be accomplished in series to build out the lab's main solar array truss and prepare the station for arrival of European and Japanese research modules.
The only real hitch in an otherwise by-the-book mission was a software commanding problem Wednesday that held up test and check out of a drive system needed to rotate the new arrays to keep them face on to the sun as the station circles the globe.
As it turned out, the glitch was actually a safety feature built into higher level supervisory software that controllers had not taken into account. Once they did, checkout of the solar alpha rotary joint, or SARJ, went smoothly and the Atlantis astronauts were cleared to press ahead with array deployment early today.
During extension of an identical set of arrays in 2000, many of the compressed slats in the solar blanket initially stuck together due to the effects of low temperatures and atomic oxygen.
When the stuck panels broke free during deployment, the arrays oscillated more than expected and caused a tension cable to jump from its guide. The system was repaired during a spacewalk and procedures were changed for today's deploy.
Flight controllers first extended each wing a few feet to improve warming and release compression. Then the astronauts deployed the panels, one at a time, first to 49 percent and then, after waiting for more solar warming, out to a full 100 percent. The extension was done in a high-tension mode to help prevent the panels from pulling up at the bottom as the self-assembling masts extended.
The procedure worked as planned and no problems were encountered.
"Good deploy of the 2A array, very similar to the deploy of the 4A array," Atlantis commander Brent Jett called around 8:45 a.m. after the second wing was fully extended.
"Good day for space station," replied astronaut Pam Melroy from mission control in Houston. "We confirm the solar array is also fully deployed on telemetry. Congratulations!"
"We're very happy to get the array out today," Brent said. "There was never any motion on the tension mechanism until it was supposed to move at the very end. There was, however, quite a bit of spring tension and when the (stuck) panels would release, the boxes would move quite a bit, but that was the same on both arrays."
Suffredini was elated with how the deployment played out.
"A lot of folks have spent time talking about a couple of bolts (and) the software feature we rediscovered last night," he said. "But if you told me before this flight these were the only issues we were going to deal with as a program, I would have taken that and run. The only real problem I have is getting everybody to understand when we say these things are hard, really believing us, because the next flight is going to be even more difficult.
"But we're ecstatic today," he said. "The vehicle has performed in an outstanding way, the systems that make up the P3/P4 truss have all performed as advertised and we're well on our way to returning to assembly."
The new arrays, known as P4 because they're part of left-side truss segment No. 4, were wired into the station's electrical system earlier this week during a spacewalk by Joe Tanner and Heidemarie Stefanyshyn-Piper. But the panels will not begin providing power to the station until December, when the next shuttle assembly crew arrives to carry out a major electrical system rewiring.
During that flight, the left wing of the P6 solar array, currently positioned at right angles to P4 at the top of the station, will be retracted, permitting the new panels to rotate as required to track the sun.
The P6 array will be moved next August to a position just outboard of P4, completing the left side of the station's main power beam. Two other arrays will be attached to the right side of the truss in February 2007 and June 2008.
For the Atlantis astronauts, a third spacewalk is on tap Friday, starting at 5:15 a.m., to complete final closeouts of the new hardware and to repair S-band and KU-band antenna systems on the station.
While Tanner and Joe Tanner Stefanyshyn-Piper are outside, Jett and shuttle pilot Chris Ferguson plan to deploy a set of folded radiator panels on the P4 truss to provide cooling for internal electrical components.
The 1,600-pound radiator, made up of seven hinged panels housing two ammonia coolant circuits, will extend 44 feet when fully deployed at right angles to the axis formed by the array wings.
"You just can't imagine a flight being better than this one has been," Suffredini said. "Now, as we go further along, we won't have had as many years training and some of the jobs will be less difficult than what we did with the installation of this truss, some will be the same, some will be more difficult.
"And so I love the first step that we've taken and I think that's great for the team and I think that speaks volumes of the work we have to do. ... If you believe what this flight tells you, we've got a pretty good fix on what it takes. But we know we've got a lot of challenges in front of us. ... We'll be cautious with you and with ourselves to not get too overly optimistic. We're going to keep asking ourselves questions."
See the 5 a.m. status report below for detailed background on the new arrays.
07:15 a.m., 09/14/06, Update: Astronauts deploy first of two solar wings
With the international space station in free drift, the Atlantis astronauts unfurled the first of two new solar array wings today, beaming back spectacular video showing the gold-colored blankets extending like venetian blinds against the black backdrop of space
"The international space station beginning to spread its wings," said NASA commentator Kyle Herring in mission control.
The folded solar cell blankets unfurled smoothly as a self-assembling mast extended on computer command, pulling the array blankets from their storage boxes. As expected, numerous slats in the two blankets making up wing 4A stuck together because of a phenomenon known as 'stiction."
To deal with that, the array was first extended to 49 percent and then halted to let the panels warm up in the sun. That strategy worked, prompting astronaut Pam Melroy in mission control to tell the astronauts: "Just for your information, we are starting to see some of the panels release."
When deployment resumed a half hour later, the remaining stuck-together slats pulled apart with no problems, causing the blankets to ripple slightly as they released. But engineers had planned for that, deploying in a so-called high-tension mode that prevented excess movement.
"Solar array full deploy," commander Brent Jett radioed a few minutes past 7 a.m. "Several releases, where the springs went taut to release the panels. However, we didn't see any tension mechanism movement, the tension bar came up at the end. So high-tension mode did its job and released the panels successfully."
"That's great news, Brent, and we can confirm that on telemetry," Melroy replied.
With wing 4A fully extended to a length of about 115 feet, the astronauts turned their attention to the second panel, 2A, waiting for good lighting to carry out the same two-step deployment procedure. Once fully extended, the two arrays will stretch more than 240 feet from tip to tip.
05:50 a.m., 09/14/06, Update: Second solar array wing deployed to one bay
Flight controllers have successfully extended two new solar array wings a few feet to relieve compression and provide better warming. After reorienting the space station to put more direct sunlight on the mostly stowed arrays, the Atlantis astronauts plan to begin full deployment, one wing at a time, beginning around 6:25 a.m. Because of problems encountered when an idential array was deployed in 2000, when several panels stuck together and a tensioning wire jumped its spool, the astronauts will carry out today's deployment in stages. They will first extend one wing to 49 percent, wait a half hour or so to let the panels warm up more, and then proceed to a full 100 percent. The process will be repeated with the other array wing.
Engineers believe a combination of factors contributed to the "stiction" seen during the array deploy in 2000, including temperature, the effects of long-term compression and the action of atomic oxygen. By deploying in stages at warmer temperatures, they hope to avoid similar problems this time around.
05:00 a.m., 09/14/06, Update: SARJ troubleshooting, checkout complete; solar array deploy begins
Running behind schedule because of software problems, flight controllers early today began a slow, careful process to unfurl a new set of solar arrays aboard the international space station. The plan called for first deploying the huge panels just a few feet to let them warm up and decompress after years in storage. Later today, the Atlantis astronauts will send commands to fully extend the new arrays.
The initial deployment had been planned for Wednesday night, but software problems held up checkout of a large rotary drive mechanism designed to rotate the new arrays 360 degrees to stay face on to the sun as the station circles the globe.
One of two drive lock assembly - DLA - motors in the solar alpha rotary joint worked properly in an initial test, rotating the still-stowed arrays 180 degrees. But the drive gear in a redundant DLA appeared to be misaligned and testing was put on hold. Late last night, engineers traced the problem to a software commanding issue and after implementing a workaround, DLA-2 eventually moved the arrays through a 360-degree rotation as planned.
Finally, at 5 a.m., the first set of arrays - 4A - began slowly unfurling on ground command as its self-assembling mast pulled the top few feet of folded solar cell blankets from its box. The other array, 2 A, was to follow suit shortly.
The Atlantis astronauts hope to complete solar array deployment later today in stages, sending commands to unfurl the panels first to 49 percent and then to a full 100 percent in what promises to be the most visually dramatic moment of the ongoing space station assembly mission.
Here is an updated timeline of today's activities (NOTE: solar array deploy times are uncertain and not included; in EDT and mission elapsed time):
____________________________________________ 12:15 AM 04 13 00 STS/ISS crew wakeup 03:35 AM 04 16 20 EVA tool config 05:40 AM 04 18 25 ERCA troubleshooting 06:10 AM 04 18 55 Station robot arm reconfig 06:45 AM 04 19 30 Crew meals begin 11:25 AM 05 00 10 Canadian PAO event with Jett, MacLean 11:45 AM 05 00 30 Transfer tagup 11:50 AM 05 00 35 CNN, NPR interview Jett, Vinogradov, Williams 11:50 AM 05 00 35 Infrared camera setup 12:10 PM 05 00 55 EVA-3: Procedures review 02:20 PM 05 03 05 EVA-3: Campout mask pre-breathe (Tanner, Piper) 03:05 PM 05 03 50 EVA-3: Crew lock 10.2 depress 03:45 PM 05 04 30 ISS crew sleep begins 04:15 PM 05 05 00 STS crew sleep begins (Tanner, Piper in airlock)Each solar array wing is 15 feet wide and 115 feet long. Extending in opposite directions, the wings will stretch more than 240 feet from tip to tip when fully deployed. The so-called P4 array, or port 4 segment of the station's main power truss, is bolted to the SARJ mechanism on the outboard side of the P3 truss segment that also serves to route power and data to and from the solar panels. When completed, the space station's power truss will stretch more than a football field from end to end. Two huge solar arrays on each end of the truss will track the sun as the station circles the globe, rotating and changing pitch as required to maximize electrical generation.
Finishing the main truss and wiring in the new arrays is a major element of near-term station assembly missions.
One set of arrays, P6, is already attached to the station, providing power for the U.S. segment of the outpost. It is attached to the Z1 truss that extends upward from the Unity module at right angles to the main solar array truss. It will be moved next August to its final position next to the P4 arrays that were attached to the station Tuesday by Atlantis' crew.
Two other sets of identical arrays will be mounted on the right side of the truss during shuttle assembly flights in February 2007 and June 2008.
Designed by Boeing, the newly attached P4 truss features two motor-driven self-assesmbling masts designed to pull out a pair of solar blankets. For launch, the arrays are folded like venetian blinds in blanket boxes measuring 15 feet long but just 20 inches thick.
The P3 truss was delivered to the Kennedy Space Center in November 1999. P4 followed suit in July 2000. The solar array blankets have not been unfolded since they were originally stowed for launch.
Prior to Columbia's launch in January 2003, the arrays were certified to operate and deploy normally when stowed for up to 45 months. Because of the extended downtime after the Columbia accident, one of the blanket boxes on P4 was removed and shipped to California for deployment tests. A replacement blanket was installed aboard P4.
As it turned out, the deployment tests went well and the blanket, which had been stowed 39 months at that point, worked normally. As a result, the certification age limit was boosted to 82 months. As of launch aboard Atlantis, the P4 blankets had been stowed for 67 and 73 months respectively.
One other consequence of the Columbia recovery and subsequent launch delays was a decision to replace all 12 batteries in P4. The 372-pound batteries were swapped out in March and August of 2005.
The solar array wings were designed by Lockheed Martin. They weigh more than 2,400 pounds and feature some 33,000 solar cells per blanket. They are designed to produce more power than the station actually needs to compensate for normal degradation as the outpost ages.
The blankets must face the sun directly for maximum electrical generation and two mechanisms are in place to do just that. The wings can be rotated about their long axis by beta gimbal joints, much like the pitch of an airplane propeller can be adjusted. The SARJ, on the other hand, rotates the arrays through 360 degrees like a waterwheel around the axis of the main truss.
The P4 integrated equipment assembly, or IEA, is a cube measuring 16 feet on a side and weighing nearly 17,000 pounds. It includes direct current converters, 12 batteries, battery chargers, control computers and an ammonia cooling system to keep the electronic gear at the proper temperature. A single set of folding radiator panels will extend 44 feet when fully deployed.
Most of the work to ready the new P4 arrays for extension "is done by the flight control team," Jett said. "The EVA crew does the physical work, in terms of, positioning the arrays and releasing all the bolts and the launch restraints. But then the preparation to actually make the deployment happen, all the activation sequence and the activation of the rotary joint, is all performed by the ground team."
The P4 arrays are identical to P6, which was attached to the space station during shuttle mission STS-97 in December 2000. When the first blanket was deployed, engineers were surprised to see several of the blanket panels had stuck together. When they jerked free, a tensioning cable jumped its guides and required repairs on a subsequent spacewalk. For the second array's deployment, the crew let the sun warm up the array and deployed it in a so-called high-tension mode. That technique worked, and the array unfurled without incident.
For the P4 deploy, the arrays will first be extended the length of a single bay of each mast - a few feet worth - to relieve compression and to begin warming up the panels. "The one-bay deploy is basically to start the relaxation of the blankets and to get ahead," station flight director John McCullough said Wednesday. "The time we're in an inertial attitude, the attitude where we continuously point the arrays at the sun, is limited because the rest of the space station doesn't really like that atitude.
"For this deploy, we want to have the sun in a certain cone to warm the back of the blankets and there's a limit to that. We can only be there for three revs around the Earth."
Working in stages, the astronauts will extend the 4A mast to a distance of 49 percent early Thursday, wait a half hour or so for additional solar heating, and then the rest of the way to full extension. They will repeat that process for the 2A mast. It will take about 90 minutes for each panel to fully deploy.
"We're not too terribly concerned about stiction on the deploy," said Tanner, a veteran of the STS-97 mission. "We know it might happen in certain panels. The team went hard to work after STS-97 to figure out the mechanism of stiction and what we can do to reduce it. They came up with a good operational plan to nominally deploy.
"Now if for some reason one or two panels sticks after all that, then we can go out EVA, it would be on EVA 3, and actually manually peel the panels apart for the first 40 inches or so and doing a nominal deploy after that. All of our tests say they will peel open very easily. So we're not too terribly concerned about that."
Space station Program Manager Mike Suffredini agreed that experience gained during the STS-97 mission in 2000 should result in a smooth deploy.
"The good news is we've done it twice before," Suffredini said. "The first time we deployed one of these arrays, we learned about a stiction issue that existed. After quite a bit of work during that mission, we deployed the second array in a little bit different technique, which allowed us to be successful. We learned a lot about techniques to get these arrays out without having the tension wire come loose, which is what happened when we tried to deploy the first one. It turns out after a lot of work ... we figured out a fix to go back in there to put it back in its original condition. And of course, the arrays have been fine ever since.
Using an engineering model, "we did quite a bit of testing on this stiction issue and how these arrays can stick together based on the silicon bead that's on the arrays and then we compress them for long periods of time before they go fly. And that was basically the cause of the problem. Over a long period of time this silicon would tend to attach itself to the back part of the array. And so we've done a number of things, largely operational changes but also on how we dealt with the arrays."
While the arrays were compressed for shipment to Florida, that pressure was relaxed until shortly before final preparations.
"Probably the largest changes were operational," Suffredini said. "We will partially deploy the array about one bay's worth and we'll let it warm up and sort of expand a little bit. Then the actual deploy process a little bit later will have us deploy the array halfway and then you'll see us sit for about 30 minutes as we warm it up and then we'll go the rest of the way.
"In addition to that, we're using what we call a high-tension mode. Instead of leaving the lower part of the array free to move up and down as the array gets deployed, we learned we need to hold it down against the bottom of the blanket box. So the new technique holds it down and then this particular deploy lets the heat warm things up, to allow the silicon to free itself, is the process we'll use to deploy. I have a lot of confidence in the deployment of the arrays."
The new solar arrays will not be rotated on the SARJ because of interference with the port wing of the P6 array and they will not provide any power to the space station until reconfigurations during the next shuttle mission in December.
For readers interested in a bit more detail, here is an overview provided by Boeing, the prime contractor.
Source: BoeingElectrical power is the most critical resource for the ISS because it allows astronauts to live comfortably, safely operate the station, and perform complex scientific experiments. Since the only readily available source of energy for spacecraft is sunlight, technologies were developed to efficiently convert solar energy to electrical power. One way to do this is by using large numbers of solar cells assembled into arrays to produce high power levels. The cells are made from purified crystal ingots of silicon that directly convert light to electricity through a process called photovoltaics. Solar cells do the job, but a spacecraft orbiting the Earth is not always in direct sunlight so energy has to be stored. Storing power in rechargeable batteries provides a continuous source of electricity while the spacecraft is in the Earth's shadow.
NASA and Lockheed Martin developed a method of mounting the solar arrays on a "blanket" that can be folded like an accordion for delivery to space. Once in orbit, astronauts deploy the blankets to their full size. Gimbals are used to rotate the arrays so that they face the Sun to provide maximum power to the Space Station. The solar arrays track the sun in two axes: beta and alpha.
P4 is the second of four PVMs that will eventually be brought up to the International Space Station, converting sunlight to electricity. The first one, named P6, was brought on orbit by the STS-97 crew in November 2000. The primary functions of the P4 photovoltaic module are to collect, store, convert and distribute electrical power to loads within the segment and to other ISS segments. The P4 PVM consists of two beta gimbal/PV array assemblies, two beta gimbal transition structures, one integrated equipment assembly and associated cabling and tubing. The P4 PVM components were assembled by Boeing in Tulsa, Okla. and Lockheed Martin in Sunnyvale, Calif. prior to final assembly and testing by Boeing at Kennedy Space Center, Fla.
There are two solar array wings (SAW) designed, built and tested by Lockheed Martin in Sunnyvale, Calif. on the P4 module, each deployed in the opposite direction from each other. Each SAW is made up of two solar blankets mounted to a common mast. Prior to deployment, each panel is folded accordion style into a solar array blanket box (SABB) measuring 20 inches high and 15 feet in length. Each blanket is only about two inches thick while in this stored position. The mast consists of interlocking battens which are stowed for launch inside a mast canister assembly (MCA) designed, built and tested by ATK-Able. When deployed by the astronauts, the SAW deploys like an erector set as it unfolds. It has two arms like a human torso when mounted on P4 which are rotated outwards by astronauts during a spacewalk so they can be fully deployed. Because these blankets were stored for such a long time, NASA, Boeing and Lockheed Martin conducted extensive testing to ensure they would unfold properly once on orbit to ensure there would be no problems with the blankets sticking together. This testing was completed in July 2003.
When fully deployed, the SAW extends 115 feet and spans 38 feet across and extends out to each side of the integrated equipment assembly. Since the second SAW is deployed in the opposite direction, the total wing span is over 240 feet.
Each solar array wing weighs over 2,400 pounds and use nearly 33,000 (32,800 per wing) solar array cells, each measuring 8-cm square with 4,100 diodes. The individual cells were made by Spectrolab and ASEC. There are 400 solar array cells to a string and there are 82 strings per wing. Each SAW is capable of generating nearly 32.8 kilowatts (kW) of direct current power. There are two SAWs on the P4 module yielding a total power generation capability approaching 66 kW, enough power to meet the needs of 30 average homes without air conditioning (based on an average 2kW of power.)
10:25 p.m., 09/13/06, Update: Drive motor indicates it's engaged; problem may be near solution
Engineers troubleshooting an apparent alignment problem with one of two drive motors in a mechanism needed to rotate new solar arrays on the international space station apparently have resolved the glitch, officials said late today.
Details were not immediately available, but sources said the problem may have been triggered by a subtle computer commanding issue. Late today, a NASA spokeswoman confirmed the drive motor in question had been successfully engaged more than three hours after the problem first cropped up, delaying initial deployment of the new solar arrays.
Engineers now plan to press ahead with checkout of the solar alpha rotary joint, rotating it through 360 degrees using the now-engaged motor, but it's not yet clear when they might begin the initial deployment of the station's new solar arrays.
THe 2,500-pound solar alpha rotary joint, or SARJ, is the centerpiece of the newly installed P3, or port three, truss that was attached to the left side of the station's main solar power beam Tuesday. It is designed to rotate outboard solar arrays so the panels can stay face on to the sun as the station circles the globe.
Engineers had hoped to begin the initial deployment of the new P4 solar arrays attached to the SARJ this evening, extending the panels a few feet to relieve compression after years of storage. The Atlantis astronauts are scheduled to fully deploy the 115-foot-long solar wings early Thursday.
But during SARJ checkout this afternoon, engineers ran into problems with one of two redundant drive motors.
One drive lock assembly, or DLA, successfully rotated the P4 arrays 180 degrees in an afternoon test. But when engineers attempted to carry out a 360-degree rotation with the redundant DLA, a sensor indicated an apparent misalignment in the gear train. A procedure was executed to clear the problem, but the misalignment indication remained.
Flight controllers then decided to hold up the initial array deployment while they assessed what, if anything, needed to be done.
07:30 p.m., 09/13/06, Update: Initial solar array deploy held up; engineers troubleshoot possible SARJ alignment issue
Engineers held up initial deployment of a new set of solar arrays aboard the international space station this evening after a possible gear train alignment problem was noticed inside a rotary joint that passed initial checkout earlier today.
THe 2,500-pound solar alpha rotary joint, or SARJ, is the centerpiece of the newly installed P3, or port three, truss that was attached to the left side of the station's main solar power beam Tuesday. It is designed to rotate outboard solar arrays so the panels can stay face on to the sun as the station circles the globe.
Engineers had hoped to begin the initial deployment of the new P4 solar arrays attached to the SARJ this evening, extending the panels a few feet to relieve compression after years of storage. The Atlantis astronauts are scheduled to fully deploy the 115-foot-long solar wings early Thursday.
But during SARJ checkout this afternoon, engineers ran into problems with one of two redundant drive motors.
One drive lock assembly, or DLA, successfully rotated the P4 arrays 180 degrees in an afternoon test. But when engineers attempted to carry out a 360-degree rotation with the redundant DLA, a sensor indicated an apparent misalignment in the gear train. A procedure was executed to clear the problem, but the misalignment indication remained.
Flight controllers then decided to hold up the initial array deployment while they assessed what, if anything, needed to be done. It is possible the problem is the result of a faulty sensor, but it's also possible some other issue is responsible.
This status report will be updated as new information becomes available.
03:30 p.m., 09/13/06, Update: Rotary joint swings into action
A 2,500-pound rotary joint seeing its first use aboard the international space station, successfully rotated a new set of still-stowed solar arrays today in a key test before array deployment early Thursday.
As installed on the left end of the station's main solar array truss Tuesday, the new panels were oriented so their cooling radiators would have extended straight up if deployed, contacting a set of operational arrays.
After checking out the new solar alpha rotary joint - SARJ - flight controllers sent commands to turn the joint, first 5 degrees and then a full 180 degrees, using one of two redundant motors. Space station flight director John McCullough said the initial checks went well and controllers will move the joint a full 360 degrees later today to test the other drive system.
"The really great news is the SARJ, the solar alpha rotary joint that we worked so hard on and talked about so much, it moved right before this briefing," McCullough told reporters. "I was pretty excited to see that. It was a great day and very visually enticing."
If all goes well, flight controllers will begin the solar array extension process late today, deploying each packed-up wing a bit more than a yard, the length of one bay of their motorized self-assembling masts. On Thursday, the Atlantis astronauts will send commands to extend the masts the rest of the way.
Once deployed, each 38-foot-wide solar array wing will stretch more than 115 feet in opposite directions. A detailed overview of solar array deployment will be posted here later today.
12:30 p.m., 09/13/06, Update: Spacewalk ends
Astronauts Dan Burbank and Steve MacLean closed a hatch and repressurized the Quest airlock module today to wrap up a successful, occasionally dramatic spacewalk to rig a massive solar array drive mechanism for operation.
The spacewalk began at 5:05 a.m. and ended seven hours and 11 minutes later at 12:16 p.m. It was the 71st space station assembly or maintenance spacewalk, pushing total EVA time to 431 hours and 54 minutes since construction began in December 1998.
Engineers, meanwhile, are checking out the solar alpha rotary joint - SARJ - on the new P3 truss in preparation for its first 360-degree rotation. The SARJ eventually will be used to drive solar arrays on the left side of the station to keep them aimed at the sun as the outpost
10:45 a.m., 09/13/06, Update: Spacewalkers free tight bolt UPDATING at 3:30 p.m. with quotes and details from NASA status briefing; quote attributed to Tanner, not Jett as stated earlier
Astronauts Dan Burbank and Steve MacLean, using their combined muscle power, a big wrench and lots of grunts and groans, finally freed an overly tight bolt today that threatened to prevent a massive rotating joint from operating properly.
"What a great day," station flight director John McCullough said when the work was done. "Today we had numerous battles with the hardware, but that's the reason we have people in space. And today it took a couple of strong folks to get the job done.
"I know it's not a very good analogy, but it was almost like giving birth today, the fighting that we had to go through and the labor pains. I hate to use that analogy because it's nothing like that. But you get the idea."
The bolt in question secured one of six large launch restraints on the 2,500-pound solar alpha rotary joint at the heart of the new port 3 truss that was attached to the space station Tuesday. The SARJ was launched with 16 launch locks on the main gear assembly and larger launch restraints, all of which had to be removed to permit rotation of the new solar array making up the outboard P4 truss.
MacLean and Burbank successfully removed the smaller launch locks, although one of the bolts used to secure a thermal blanket broke free. Astronaut Joe Tanner ran into similar trouble during a spacewalk Tuesday, prompting concern about potential debris inside the SARJ mechanism. But flight controllers said Tuesday and again today that they were not concerned.
"I didn't see this as a real big deal," said John Haensly, lead spacewalk flight director at the Johnson Space Center.
Earlier today, MacLean ran into problems freeing a bolt holding a large launch restraint in place. After breaking a socket trying to free the bolt, he and Burbank, with advice and guidance from Tanner, used a larger wrench and put their combined muscle power into the effort.
Despite concern they might snap the head off the bolt, McCullough said there was never any chance of that and in any case, Burbank and MacLean eventually succeeded, much to everyone's relief.
"Yoo hoo!" one of the astronauts yelled.
"All right!" another said.
"OK, that one's free," MacLean confirmed, prompting another astronaut to observe "now there was much rejoicing."
"You guys didn't spend enough time at the gym," someone joked.
"Whoa," Burbank said. "Yeah, Steve broke one of your tools because he didn't spend enough time at the gym."
"I hope they don't take it out of my wages, you know," MacLean said. A few moments later, astronaut Pam Melroy called from mission control in Houston, saying "we appreciate your answering that age-old question for MCC: how many astronauts does it take to unscrew a bolt? And apparently it takes three, two outside and one inside. We're very pleased, you guys did an awesome job and that was great teamwork."
"Yeah, this was an amazing effort you guys," Tanner added. "You wouldn't have imagined the drama inside here and I'm sure the drama on the ground right now, a few minutes ago."
"It would be a show stopper for rotation and (solar array) deploy," agreed Burbank.
"You betcha."
Flight controllers, meanwhile, are gearing up to begin test and checkout of the SARJ prior to ordering a full 360-degree rotation later today. The still-stowed P4 solar arrays must be rotated 180 degrees before they are deployed Thursday and after the SARJ completes its 360-degree turn, it will reverse and move back 180 degrees.
A second SARJ will be attached to the right side of the space station's solar array truss next February and engineers are anxious to check out the operation of the one in P3.
"This is a component we haven't flown yet, this is the first one we're doing," spacewalker Heidemarie Stefanyshyn-PiperPiper said in a pre-launch interview. "So that's probably one of the big unknowns, how is that joint going to react in space? If it doesn't work, then your arrays are going to be parked where they are, you're not going to be able to track the sun."
For readers interested in a bit more technical detail, here's a description of the joint from Boeing, the prime contractor:
"P3 consists of the Solar Alpha Rotary Joint (SARJ), which continuously rotates to keep the solar array wings on P4 and P6 oriented towards the sun as the station orbits the earth. Located between P3 and P4, the SARJ is a 10 foot diameter rotary joint that tracks the sun in the alpha axis that turns the entire P4 module (and eventually the P6 module when it is relocated). The SARJ weighs approximately 2,500 pounds.
"The SARJ can spin 360 degrees using bearing assemblies and a servo control system to turn. All of the power will flow through the Utility Transfer Assembly (UTA) in the SARJ. Roll ring assemblies allow transmission of data and power across the rotating interface so it never has to unwind. Under contract to Boeing, the SARJ was designed, built and tested by Lockheed Martin in Sunnyvale, Calif.
"The solar array wings are also oriented by the Beta Gimbal Assembly (BGA), which can change the pitch of the wings by spinning the solar array. The BGA measures 3 x 3 x 3 feet and provides a structural link between the Integrated Equipment Assembly (IEA). The BGAÕs most visual functions are to deploy and retract the SAW and rotate it about its longitudinal axis.
"Both the SARJ and BGA are pointing mechanisms and they can follow an angle target and rotate to that target. On-orbit controllers continuously update those targets so it keeps moving continuously as the station orbits the Earth every 90 minutes, maintaining contact with the sun at the same orbital rate. The SARJ mechanism will move much more than the BGA. The BGA will move about four or five degrees per day, whereas the SARJ will rotate 360 degrees every orbit or about 4 degrees per minute.
"The SARJ will be the first one to be installed on station and it is unique because it rotates the entire truss element, allowing it to rotate in the alpha axis rotation. The station has been using the P6 BGA to move as an alpha joint. Eventually, the SARJ will provide primary rotation with BGA doing minor movements and will be tested on this flight, but wonÕt be activated until assembly mission 12A.1."
That mission, by the shuttle Discovery, is scheduled for launch Dec. 14. During the flight, the left wing of the P6 array, currently mounted on the Z1 truss atop the Unity module, will be retracted. That will clear the area needed for the new P4 arrays to rotate as designed.
The right wing of the P6 array will be retracted during the next shuttle flight in February. If all goes well, the arrays will be attached to a spacer next to P4 next August.
08:00 a.m., 09/13/06, Update: Despite extra care, spacewalker loses another bolt
Canadian astronaut Steve MacLean ran into the same problem today that spacewalker Joe Tanner encountered Tuesday: a lost bolt from a thermal cover on a newly installed solar array truss. Unlike Tanner, MacLean never saw the spring-loaded bolt separate from its retaining clip and float away. One minute it was there, the next it was gone.
"OK, on cover eight, a bolt is missing," MacLean radioed. "Bolt alpha. I did not see it go."
"OK, Steve, I copy that, bolt 1 alpha is missing," Heidemarie Stefanyshyn-Piper replied from inside the shuttle-station complex.
MacLean and Dan Burbank were in the process of removing 12 launch locks on a massive rotary joint that ultimately will move the station's port-side solar arrays to track the sun as the station circles the globe.
The solar alpha rotary joint was launched with its main gear locked in place. To remove the launch locks, thermal covers held in place by four spring-loaded bolts have to be moved aside. The covers are reinstalled after the locks are removed.
The attachment hardware is designed to stay in place. But during a spacewalk Tuesday, a retaining clip apparently failed, or was knocked off its threads, and the clip and bolt floated away. Tanner was initially worried some of the hardware might have floated inside the SARJ but flight controllers dismissed that concern, saying they were confident the bolt and washer floated away from the station.
Based on Tanner's experience, MacLean and Burbank were taking special care not to put any stress on the bolt hardware as they worked through the removal of the remaining 12 launch locks. MacLean even kept an eye out for the bolt that vanished Tuesday.
"Heide and Joe, I've been looking all along for that bolt," he radioed at one point. "Haven't seen anything."
He was in the process of re-attaching a thermal cover when he noticed one of his bolts had disappeared.
"I'm standing by for your words," MacLean radioed after reporting the lost bolt. "Would you like me to remove the cover and take a look inside? The cover is tacked on right now with three bolts."
Flight controllers asked him to do just that, adding "we're just specifically concerned about whether the washer is still there."
"OK, the cover is removed again, slowly turning it around," MacLean said a few moments later. "And the washer is gone."
Looking inside the truss, he reported seeing "nothing at all that looks like a washer." He then re-attached the thermal cover with the three remaining bolts and pressed ahead.
Assuming the spacewalk stays on schedule, flight controllers plan to begin activating the SARJ around 11:15 a.m. If no problems are found, a drive motor will begin turning the main gear about an hour later to rotate a new, still-stowed set of solar arrays 180 degrees. That will put the P4 solar array blanket boxes in the proper position for deployment Thursday.
As part of its initial checkout, the SARJ will actually rotate the outboard P4 array truss a full 360 degrees before reversing direction and moving back to the 180-degree position.
Flight controllers plan to extend the panels a few feet late this evening. On Thursday, the astronauts will complete the job, sending commands that will cause a motorized mast to extend, pulling the folded solar panels from their boxes like venetian blinds. Fully extended, the arrays will stretch 240 feet from tip to tip.
05:10 a.m., 09/13/06, Update: Burbank, MacLean begin spacewalk
Astronauts Dan Burbank and Canadian Steve MacLean, floating in the space station's Quest airlock module, switched their spacesuits to internal battery power at 5:05 a.m. today to kick off a planned six-and-a-half-hour spacewalk. The goal of the outing is to complete work on a massive rotary joint that will slowly turn a new set of solar arrays to keep them face on to the sun.
This is the 71st spacewalk devoted to space station assembly and maintenance since construction began in 1998 and the second of three planned by the Atlantis astronauts. Joe Tanner and Heidemarie Stefanyshyn-Piper completed the initial setup of a new solar array truss Tuesday and will carry out a final spacewalk Friday, the day after the new arrays are unfurled.
CBS News ISS Spacewalk Stats: http://www.cbsnews.com/network/news/space/evastats.html Like Tanner and Piper, Burbank and MacLean spent the night inside the Quest airlock at a reduced 10.2 psi air pressure to purge their bodies of nitrogen and prevent the bends while working in 5-psi spacesuits. The so-called campout procedure shortens preparation time by about an hour.
The objectives of today's spacewalk are to remove 14 of 16 launch locks and a half dozen launch restraints to free the solar alpha rotary joint ring mechanism for rotation. Tanner and Piper removed two launch locks Tuesday as a get-ahead task and ran into problems when one spring-loaded bolt broke free. Despite some initial concern on Tanner's part that the bolt might have found its way inside the rotary joint mechanism, engineers believe it floated free and poses no threat to the SARJ. Even so, Burbank and MacLean will be on guard to prevent any similar problems today.
The SARJ makes up the interface between the newly installed port 3 and 4 solar array truss segments that were attached to the left side of the station's main power beam Tuesday.
The SARJ features a large gear and two redundant drive motors called drive lock assemblies, or DLAs, that ultimately will rotate two sets of outboard solar arrays through 360 degrees like giant paddle wheels as the station circles the globe to maximize solar power production.
"The SARJ, the DLAs, those mechanisms, although they've been tested on the ground, we don't have any history with them on orbit," said Atlantis commander Brent Jett. "So those represent a special challenge in terms of both engineering and operations."
Said Tanner: "The big unknown is how is SARJ going to behave when we try to activate it. It should be interesting. But hopefully not too interesting."
Along with removing the remaining launch locks, Burbank and MacLean also will complete the installation of inboard stiffener struts to provide the necessary structural rigidity.
"Steve and I are going to spend the bulk of EVA 2 removing the whole series of these launch locks and launch restraints," Burbank said in a NASA interview. "We're going to spend most of our time right in the middle section of the P3/P4 truss driving a lot of bolts with a lot of power tools. After all that's done, we've removed all this hardware that's kept the P3 and P4 trusses properly oriented for launch, we're going to deploy the SARJ braces, the solar alpha rotary joint braces, a series reinforcement structures that will help to stabilize that, that alpha rotary joint on both sides. So we'll spend a lot of time doing that.
"Then, time permitting, we'll be able to do some get-aheads, some of the work we're planning on doing on EVA 3. But EVA 2's kind of different. We're going out with a different kind of a CO2 scrubber in the (spacesuits) that allow us to go a little bit longer than planned if necessary."
Here is an updated timeline of today's activity (in EDT and mission elapsed time):
EDT DD HH MM EVENT _____________________________________________ 05:05 AM 03 17 50 EVA-2: Spacesuits to battery power 05:15 AM 03 18 00 EVA-2: Airlock egress; setup 05:40 AM 03 18 25 SSRMS camera viewing 05:55 AM 03 18 40 EVA-2: EV4: SARJ prep (remove covers/restraints) 05:55 AM 03 18 40 EVA-2: EV3: SARJ prep (remove covers/restraints) 08:30 AM 03 21 15 ISS: Transfer operations 10:10 AM 03 22 55 EVA-2: Stow P3 keel pin and drag link 10:55 AM 03 23 40 EVA-2: Payload bay cleanup, airlock ingress 11:15 AM 04 00 00 MCC: SA/SARJ activation and checkout begins 11:15 AM 04 00 00 Transfer tagup 11:35 AM 04 00 20 EVA-2: Airlock repressurization 01:15 PM 04 02 00 12A EMU swap EVA-2 02:00 PM 04 02 45 Mission status briefing on NASA TV 03:45 PM 04 04 30 ISS crew sleep begins 04:15 PM 04 05 00 STS crew sleep begins 05:00 PM 04 05 45 Daily video highlights reel on NASA TV 06:00 PM 04 06 45 Post-MMT briefing on NASA TV 07:00 PM 04 07 45 MCC: 4A solar array mast deploy (1 section) 11:05 PM 04 11 50 MCC: 2A solar array mast deploy (1 section)Burbank's call sign is EV-3 and MacLean is EV-4. Burbank's suit features horizontal red dashes while MacLean's sports diagonal dashes.
Once in place at the P3/P4 work site, the astronauts will start removing the 14 launch locks, a multi-step procedure that requires them to first release an inboard clamp; remove and temporarily stow a thermal cover; remove four bolts from the launch lock; and reinstall the thermal cover.
Once that work is done and the bolts are safely stowed in a transfer bag, the spacewalkers will remove six outboard launch restraints and install the remaining brace beams needed to stiffen the inboard side of the SARJ interface.
"Dan and I spend a lot of time around that solar array rotary joint, making sure that it's ready so that that joint can move later on during the mission," MacLean said. "So we're removing all the launch locks associated with that, and that takes us a while because it was very important to minimize the vibration of that area during launch and we have several launch locks to take off. In addition, we will stiffen up the truss. ... Here we are, construction engineers, where we'll basically remove a brace and then bring it over and then reattach it, and that stiffens up the torsional mode of the truss. We do something similar on the, on the P4 side.
"We have some AJIS (Alpha Joint Interface Structure) struts that if Joe and Heide haven't got them done the day before we will do the AJIS struts on the P4 side, which again stiffen up the torsional mode of the P4 side."
If all goes well, mission controllers will activate the SARJ later today and rotate it 180 degrees to properly position the new solar arrays for deployment. The arrays will be extended one bay tonight by flight controllers in Houston as a confidence check and then fully extended by the astronauts Thursday.
"The EVA crew does the physical work, in terms of positioning the arrays and releasing all the bolts and the launch restraints," Jett said in a NASA interview. "So the physical work is done by the EVA team but then the preparation to actually make the deployment happen, all the activation sequence, and the activation of the rotary joint, is all performed by the ground team.
"ItÕs a tremendous amount of work that needs to be done, simultaneously, not only during the EVAs but also during those two nights when weÕre asleep. The ground teamÕs working very hard to get the arrays, ready. When we wake up (Thursday), if everything goes well, the ground is going to be ready to go. We position a few cameras, so we can monitor the deployment and then we go to the computer and command the arrays to deploy. Now, hopefully, everything will go very smoothly ... and we'll get the arrays out in a couple of orbits."
But the SARJ will not begin rotating the new arrays until after a December shuttle assembly mission to complete critical cooling and electrical system changes and to retract a solar array that is currently in the way. That set of arrays eventually will be mounted just outboard of the new P4 solar panels to complete the left side of the main truss.
06:15 p.m., 09/12/06, Update: Atlantis' heat shield gets clean bill of health; shuttle cleared for re-entry
NASA's Mission Management Team today gave the shuttle Atlantis' heat shield a clean bill of health, formally clearing the ship and its crew for a normal re-entry Sept. 20 if no other problems develop.
MMT Chairman John Shannon said an exhaustive review of space- and ground-based imagery, wing leading edge sensor data and laser scans in orbit normally takes five days to complete. But this time around, the work was done in half the time, thanks to the performance of Atlantis' external tank and the team's increasing familiarity with post-Columbia inspection procedures.
"We were able to clear all of the thermal protection system in 60 hours," Shannon said. "My best estimate was always five days, so we did it in half the time. That just shows how much better the processes are getting and the people are getting at running through the processes."
Engineers decided Monday no additional heat shield inspections were needed. But two open items remained on the books: what appeared to be a protruding insulation blanket on Atlantis' right-side rocket pod; and a protruding gap filler sticking up from heat shield tiles on the belly of the orbiter.
As it turns out, it wasn't a gap filler at all.
"It was kind of a curious thing, when they started looking at the installation records, they had no record there was a gap filler in that location," Shannon said. "That caused them to be a little bit curious and they went and looked at the baseline (pre-launch) imagery and there wasn't a gap filler installed in that area."
On closer inspection, engineers realized what appeared to be part of a gap filler sticking up from the surrounding tile was actually part of a plastic shim, used during tile installation to ensure proper spacing. Shims are removed after use but this one apparently was missed.
Protruding gap fillers, not uncommon, can cause the smooth flow of hypersonic air across the belly of the shuttle to become turbulent during re-entry, which can cause areas of more extreme heating downstream. They earlier turbulent flow begins, the greater the potential for damage.
The exposed shim, Shannon said, "is not an issue at all. It's sticking out just a little bit. Since it is plastic, it will melt very easily. They ran a test on it, it'll soften at about 250 degrees Fahrenheit and it melts at about 450 degrees Fahrenheit and it will see that melting environment seven minutes before we hit Mach 25. So before we really hit the sensible atmosphere, that piece of shim stock will be long gone. So we are not worried about it."
Just to be safe, engineers carried out an analysis that assumed the shim was, in fact, a gap filler. The results showed Atlantis could safely enter as is even in that case. Two other protruding gap fillers were spotted earlier but neither poses a threat.
As for the suspect insulation blanket on the shuttle's right-side orbital maneuvering system pod, Shannon said closer inspection using a camera on the space station showed it was not a problem and Atlantis was cleared for a normal re-entry.
One final heat shield inspection will be conducted after Atlantis undocks from the space station to make sure no orbital debris or micrometeoroids hit the spacecraft after it reached orbit.
On another front, Shannon said he is optimistic NASA will be able to resume night launchings in December when the next space station assembly mission is scheduled for liftoff. "The team overall does feel extremely confident about launching at night," he said. "The radar that we have, we got another test of it this flight, and it worked extremely well for us. We also think we'll get some good imagery still just from the backlighting form the solid rocket boosters. So we're feeling good about the night launch.
"What you might lose for a night launch is further understanding of the external tank or the solid rocket boosters or the environment that we're flying in. Launching at night does not impact the safety of that crew, because we're going to do the full inspection just like we did on this flight. So, all you would lose launching at night is additional information about the environment that you might apply to ... future shuttle missions. It will not affect, though, the safety of the crew that actually launches at night. So we're feeling very comfortable that we could do that."
Shannon also said he was optimistic about eventual approval of flight to service the Hubble Space Telescope. NASA Administrator Mike Griffin is expected to make a decision one way or the other in October.
But a Hubble flight would not be able to take advantage of the space station as a safe haven in the event of non-repairable heat shield problems - the two spacecraft are in different orbits - and it may not be possible to launch a second shuttle on a rescue mission.
Shannon said he was heartened by the continued good performance of the external tank, by ongoing work to improve the tank's insulation and by development of heat shield repair techniques. But a second shuttle launch pad may not be available for a rescue mission and a Hubble repair crew might have to rely on their own ability to inspect the shuttle and carry out repairs, if necessary.
"A lot of things are lining up that says Hubble is going to be a doable kind of thing," Shannon said. "The real question on Hubble is going to be the launch on need, because that's going to be extremely difficult to do. You just don't have the orbital lifetime on a Hubble mission to be able to get another vehicle launched. It's going to be very tough.
"So we're going to have to go into the Hubble decision not counting on the launch-on-need vehicle. And that's the difficult question the agency's going to have to do. Do we have enough confidence in the design, do we have enough confidence in our inspection and repair to be able to do that? And I think that's where the discussion is mostly going to lie."
11:45 a.m., 09/12/06, Update: Spacewalk ends; all objectives accomplished; lost bolt prompts discussion UPDATED at 4 p.m. with flight director's briefing; lost bolt not a concern
Astronauts Joe Tanner and Heidemarie Stefanyshyn-Piper successfully wired in a new solar array truss segment today, removed launch restraints and deployed stowed appendages during a nearly flawless six-hour 26-minute spacewalk, the first of three complex excursions planned for the shuttle Atlantis' space station assembly mission.
"It's been a whirlwind few days here, a lot of hard work has really paid off," said lead station flight director John McCullough. "This EVA was unique, again because we had to power down half the space station. ... We had 13 umbilicals that had to be mated to supply power from the two channels on the space station and those were all accomplished successfully.
"After the EVA, the powerups went very well, all the systems are looking very good, there are no issues being tracked right now with the new hardware, it's all in good condition."
Shuttle commander Brent Jett, who stayed in the background today as Tanner and Piper worked outside, radioed flight controllers just before bedtime to offer the crew's praise for successfully carrying out the tightly scripted electrical switchovers required to connect the new truss.
"Would you pass along to the station team, everybody up here was really awed by the job they did today with all the powerups, the powerdowns, the activations," he said. "We were really running hard to keep up with them. They worked real hard for this day and they just did a great job."
Other than a few tighter-than-expected bolts - and the astronauts removed 167 in all - the only problem occurred late in the spacewalk when Tanner, removing one of 16 launch locks around a massive rotating joint, lost a washer and a bolt with a captive spring.
While Tanner expressed some initial concern that the bolt might have found its way inside the truss where it could possibly interfere with the operation of the rotary joint, McCullough and John Haensly, lead spacewalk officer, said they were confident that did not happen.
"We're pretty certain it didn't go into the structure," Haensly said. "Basically the only open space ... was the cover that he had removed and actually visually saw both the washer and the bolt and spring go off in a (different) direction."
While any sort of debris in the rotary joint would be a cause for concern, he said, "we're pretty certain it didn't go in."
The spacewalk, the 80th devoted to space station assembly and maintenance, began at 5:17 a.m. and officially ended at 11:43 a.m. when the astronauts repressurized the Quest airlock. With the completion of today's spacewalk, 61 astronauts representing the United States, Russia, Japan, Canada, Germany and France have logged 424 hours and 43 minutes building and maintaining the orbital lab complex.
"Joe and Heide, you did a phenomenal job and set the bar very high for the rest of assembly," astronaut Pam Melroy radioed from the space station control center.
"Well, we just did what we were told, Pam," Tanner joked. "We just did the best we could do, that's all we wanted to do, right Heide?"
"That's all I wanted to do," Piper said.
"Amen."
Tanner, Piper and their shuttle crewmates - commander Brent Jett, pilot Chris Ferguson, Dan Burbank and Steve MacLean - originally trained to carry out this mission in 2003, the next flight in the sequence after Columbia's ill-fated voyage.
Station assembly was put on hold in the wake of the disaster, but the Atlantis astronauts stayed together and the years of training paid off with a remarkably smooth spacewalk that belied the complexity of of the required tasks.
"Shuttle flights are definitely a hurricane when they come to the space station as far as activity goes and it takes a lot of activity in a very short time," McCullough said. "We're right now in day two of that hurricane and things are going very well."
Along with accomplishing all of their primary objectives - wiring in the new P3/P4y truss, deploying solar array appendages, removing launch restraints and engaging stiffeners and rotary joint drive motors - the spacewalkers had enough time left over to accomplish a few tasks originally scheduled for a spacewalk Wednesday by Burbank and MacLean.
The primary items on the agenda Wednesday were to remove 16 launch locks from the massive rotary joint that ultimately will spin the new arrays to follow the sun, along with six other restraints that must be removed before the joint can move freely.
The launch-lock removal is a multi-step procedure that requires the astronauts to first release an inboard clamp; remove and temporarily stow a thermal cover; remove four bolts from the launch lock; and reinstall the thermal cover. Tanner and Piper were asked to remove two of those launch locks to give Burbank and MacLean a sense of how that work might go.
As it turned out, the only snag of the day came when Tanner lost the bolt, spring and washer while working on one of the launch locks. The captive washer that normally would keep the spring-loaded bolt in place apparently came off the threads on the end of the bolt, perhaps when it was inadvertently bumped.
"Well, this is unfortunate," Tanner said, clearly disappointed. "The washer is gone, it went in a good direction, forward. The bolt and spring stayed together and I only got a glimpse of it, but it departed pretty much zenith (in an upward direction). I guess it could have ricochetted off anything in between me and the (upper) corner."
"The question would be, did it go into structure or away from structure?" mission control asked.
"Well, it was breezing across the surface of structure," Tanner replied. "It could have gone right over Heide's head, but she wouldn't have known to look up. And it was dark anyway."
After another inspection, he said "I don't see any way it could have gotten in" the truss. "I don't see it anywhere."
Back inside the space station, Tanner, clearly thinking about the lost bolt, called mission control one more time to offer details about its possible trajectory. Melroy thanked him, saying "we think you did a great job and we sure appreciate all the extra detail, but we don't think it's going to be a problem."
"Well, I just hope that bolt is on its way to mother Earth right now and not hanging around SARJ," he said, referring to the solar alpha rotary joint.
"We do, too," Melroy said. "We'll work it some more tomorrow, but don't worry about it."
Haensly said Burbank and MacLean will pay close attention to the fasteners when removing the remaining launch locks Wednesday. But Piper had no problems with the one she removed today and no additional problems are expected Wednesday.
09:10 a.m., 09/12/06, Update: Spacewalk ahead of schedule
Astronaut Joe Tanner has finished wiring in a new solar array truss segment on the international space station, plugging in a final seven data and electrical cables to complete the primary objective of today's spacewalk.
With all 13 umbilicals now connected, data can flow to and from the new truss segment and station electricity can power internal heaters needed to keep electronic components warm until the new solar arrays are unfurled Thursday.
Running more than an hour ahead of schedule, the astronauts have unfolded and locked in place the P4 solar array blanket boxes, engaged two motors that later will drive a massive rotary joint to move the arrays as required to track the sun and deployed struts to provide additional structural stability.
"All has gone very smoothly on the first spacewalk to bring the P3/P4 truss to life aboard the international space station," said NASA commentator Kyle Herring.
07:50 a.m., 09/12/06, Update: Solar array boxes deployed; rotary joint prepped
Floating at the far end of a newly attached truss, astronaut Heidemarie Stefanyshyn-Piper rotated four solar array blanket boxes into position today, appearing in spectacular video against the backdrop of the Brazilian rain forest and the Amazon River 220 miles below.
The truss and solar array components dwarfed Piper in the stunning video, giving viewers a taste of things to come when the solar panels are unfurled Thursday, stretching 240 feet from tip to tip.
Two hours and 15 minutes into a planned six-and-a-half-hour spacewalk, Piper and astronaut Joe Tanner are running ahead of schedule and have encountered no significant problems despite the complexity of the work.
Piper struggled a bit to push one of the two sets of solar array blanket boxes from the stowed to deployed position and Tanner had to lend a bit of elbow grease to get the job done. But that's not unusual with this equipment - Tanner had similar trouble during a spacewalk in 2000 - and both sets of array boxes eventually were locked in place.
Tanner is wrapping up work to engage drive motors that eventually will power a massive rotary joint in the P3 truss segment to spin the new solar arrays like a huge waterwheel to keep the panels pointed at the sun as the station circles the globe. When that task is complete, he will hook up seven more power and data cables to complete the job of wiring the new P3/P4 solar array truss segment into the space station's power grid.
06:10 a.m., 09/12/06, Update: Tanner completes first set of power, data connections
Astronaut Joe Tanner, working on the lower side of the space station's solar array truss, successfully hooked up six power and data cables between the port 1, or P1, segment and the newly installed P3 segment. Tanner finished the connections around 6:08 a.m.
A second set of seven cables will be connected later in the spacewalk to complete the most critical task in today's excursion: providing station power to internal heaters needed to keep sensitive electronic gear warm until the new arrays are unfurled Thursday.
Astronaut Heidemarie Stefanyshyn-Piper, meanwhile, is releasing launch restraints on the solar array blanket boxes on the P4 segment. Amid the work, flight controllers called to make sure the astronauts knew that mission managers had ruled out any need for additional heat shield inspections. The decision was made after the crew went to bed Monday evening.
"That's wonderful, that means we've got a good vehicle," Tanner said when told of the decision.
05:20 a.m., 09/12/06, Update: Spacewalk begins
Astronauts Joe Tanner and Heidemarie Stefanyshyn-Piper, floating in the space station's Quest airlock module, switched their spacesuits to internal battery power at 5:17 a.m. to officially begin a planned six-and-a-half-hour spacewalk.
This is the 70th spacewalk devoted to space station assembly and maintenance since construction began in December 1998. Going into today's excursion, 43 NASA astronauts, 13 Russians and four astronauts representing Japan, Canada, France and Germany had logged 418 hours and 17 minutes of spacewalk time building and maintaining the international outpost.
Tanner, veteran of a Hubble Space Telescope servicing mission, logged 33 hours and 21 minutes of EVA time in five previous spacewalks. Piper, a former Navy diver, is flying for the first time.
The primary goal of today's spacewalk is to connect 13 umbilicals to provide station electricity to a new solar array truss segment that was attached to the space station's unfinished power truss earlier this morning. The electricity is needed to operate internal heaters until the new arrays can be unfurled later this week. The astronauts also plan to release a variety of launch restraints and to set up the truss for array deployment.
The new P3/P4 truss segment was attached with four motorized bolts. Engagement of three bolts was required to consider the truss firmly attached and that was accomplished by 4:35 a.m. The fourth and final bolt was fully engaged by 5:06 a.m.
To get to the work site on the end of the port 1 truss segment, Tanner and Piper will first exit the Quest airlock, using 55-foot-long safety tethers. Crossing over a spur to the S0 truss atop the Destiny module, the spacewalkers will move across the forward face of the truss to the port side and, reaching the end of their safety lines, hook up to a different 55-foot tether. Once at the P1/P3 interface, they will swap tethers again, switching to 85-foot safety lines.
A key aspect of the spacewalk is the tight choreography between flight controllers, Tanner and Piper as the ground powers down one channel of the station's electrical grid at a time to permit the astronauts to safely plug in the umbilical cables that will route power and data to and from P3/P4.
The 13 umbilicals will be connected in stages. The first six, located on the lower side of the truss, will be connected as soon as Tanner gets in position about 45 minutes into the spacewalk. The second set of seven umbilicals, located on the top of the truss, will be connected about three hours later.
See the 2:30 a.m. status report for complete details.
04:35 a.m., 09/12/06, Update: P3/P4 solar array truss bolted into place on space station
Canadian astronaut Steve MacLean, operating the space station's Canadian-built robot arm, carefully positioned a 35,000-pound 45-foot-long solar array truss today so motorized bolts could engage to lock it to the station's main cross beam.
The first three of four anchor bolts, the requirement for a successful attachment, were secured by 4:35 a.m. The fourth bolt then was to be tightened. There were no problems of any significance this morning and the work was accomplished on time.
The mechanical attachment of the $372 million truss segment completed the first of the day's two major objectives, clearing the way for astronauts Joe Tanner and Heidemarie Stefanyshyn-Piper, already suited up in the station's Quest airlock module,to begin a planned six-and-a-half-hour spacewalk.
The goal of the excursion is to wire the new truss into the station's power grid and to begin the process of readying the new solar arrays for deployment Thursday.
The spacewalk is expected to begin around 5:15 a.m.
02:30 a.m., 09/12/06, Update: Astronauts gear up for spacewalk; solar array attachment
The Atlantis astronauts are gearing up to install a $372 million set of solar arrays on the international space station today, setting the stage for a complex spacewalk to make critical electrical connections.
"We are really looking forward to this," Canadian astronaut Steve MacLean radioed mission control early today. "Should be spectacular."
The first item on the agenda is the mechanical attachment of the 35,000-pound P3/P4 truss, launched aboard Atlantis and held overnight out over the shuttle's left wing on the end of the space station's Canadarm 2 space crane.
Working at a robotics control station inside the Destiny laboratory module, MacLean began maneuvering P3/P4 into position for attachment to the left end of the station's unfinished solar array truss around 2 a.m. Once properly lined up and positioned, four motorized bolts on the end of the P1 truss segment will engage to lock the new truss element in place.
"I'll maneuver the P3/P4 truss around up to the P1 truss, an operation that will take about 45 minutes, to the preinstall position nine centimeters away from the center of P1," MacLean said. "Then you have to wait for the rates to damp out, that takes about 30 minutes plus or minus five or 10 minutes probably, then we move in for the final install using the Canadian Space Vision System, which gives me the guidance data."
The Space Vision System uses television cameras and powerful software to measure the precise locations of large black dots attached to the truss elements. The SVS software computes the relative positions of the markings to give MacLean very precise distance and orientation information. Temperature effects can cause distortions of up to five inches, MacLean said, and misalignments of 1 to 2 degrees. The SVS will help compensate for any such effects.
"It'll take about an hour to get to the pre-install position there, and then we have to wait for an attitude change that we need in order to have the P3/P4 truss at a thermally viable position," MacLean said. "And then we install. Fergy (pilot Chris Ferguson) will come over and back me up with the Space Vision System and he will basically provide that data to me, and then using that data I will guide the P3/P4 truss in to the P1 Truss. And that'll be it. A good day."
The actual attachment is automatic. Once P1 and P3 are in close proximity, four motorized bolts on P1 will drive into attachment fittings on P3, firmly locking the two truss elements together. Three of four bolts must engage to call the operation a success.
At that point, astronauts Joe Tanner and Heidemarie Stefanyshyn-PiperPiper, now suited up in the station's Quest airlock module, will float out into space and begin the first of two back-to-back spacewalks to hook up and activate P3/P4.
The spacewalk, the 70th devoted to space station assembly and maintenance since construction began in December 1998, is scheduled to begin at 5:15 a.m.
The astronauts spent the night inside the Quest airlock at a reduced pressure of 10.2 pounds per square inch to help purge nitrogen from their bodies. The so-called camp out procedure was designed to shave about an hour off the time needed to prepare for today's spacewalk while helping ensure the astronauts don't get decompression sickness working in their 5-psi spacesuits.
The primary goal of the outing is to remove launch restraints, to unfold and lock in place the boxes holding the stowed solar array panels and to connect 13 electrical umbilicals to provide station power to internal heaters. The power is needed to keep internal electrical components warm until the now-stowed arrays are unfurled Thursday.
"Once three of four of those bolts are mated, we'll go ahead and send the crew EVA and perform the activities that we need to do to make the element survivable," said station flight director John McCullough. "All the power connections, the 13 umbilicals that need to be mated and all the activities to get ready for solar array deploy start on EVA-1. The power hookups all are completed by the end of EVA 1 and the element is completely survivable."
The station's solar array truss currently consistes of three segments. S0, the center section, is mounted atop the Destiny laboaratory module. Segments S1 and P1 are attached to the right and left ends of S0 respectively. The P3/P4 segments will be bolted to P1 on the port, or left, side of the truss. There are no P2 or S2 segments.
To get to the P1-P3/P4 worksite, Tanner and Piper will first exit the Quest airlock, using 55-foot-long safety tethers. Crossing over a spur to the S0 truss atop the Destiny module, the spacewalkers will move across the forward face of the truss to the port side and, reaching the end of their safety lines, hook up to a different 55-foot tether. Once at the P1/P3 interface, they will swap tethers again, switching to 85-foot safety lines.
A key aspect of the spacewalk is the tight choreography between flight controllers, Tanner and Piper as the ground powers down one channel of the station's electrical system at a time to permit the astronauts to safely plug in the big umbilical cables that will route power and data to and from P3/P4.
"The ground and the crew are very highly choreographed," McCullough said. "The ground has about 100 pages of ground procedures to execute in order to power down and safe connections for the EV crew to mate the 13 umbilicals. They're done on two different channels, so we have to power down one channel first, give them a go to hook up those umbilicals, then they give us a go and we power that channel back up again. We have to complete that before we can take down the next channel so we can maintain connectivity and power to the space station.
"It takes about an hour and a half between the two sets of umbilicals and when that's complete, the second set of umbilicals will be given a go and they'll do that. In between that time, there are other activities for the crew to do to get prepared for solar array deploy on flight day six."
For astronauts in the Destiny lab module, McCullough said in an interview, "a segment of the lights are going to go out that aren't on that channel. You want to be on the cooling loop system that's supplied by the other channel, so we switch over to that. You want to make sure your air circulation system is powered. ... We want to make sure we're switched over to the other side as much as possible."
In one case, he said, the astronauts in the lab will use a jumper cable to keep avionics rack 2 going, which houses critical command and control computers that otherwise would get shut down during the P3/P4 powerup/powerdown cycle.
Along with hooking up the umbilicals, Tanner and Piper will remove a variety of launch locks and restraints to prepare the solar arrays for deployment later in the mission and begin the process of preparing the massive solar alpha rotary joint, or SARJ, for operation. The rotary joint will permit the new arrays to rotate like a giant waterwheel to track the sun as the station circles the globe.
"The solar alpha rotary joint is locked in place for launch," McCullough said. "It has 16 launch locks and a lot of braces that need to be installed to support rotation and we can't deploy the arrays until all of those things are completed."
Tanner's call sign is EV-1 and he will wear a spacesuit with solid red stripes around the legs. Piper, wearing a suit with no markings, is EV-2. Here is an updated timeline of today's events (in EDT and mission elapsed time):
EDT DD HH MM EVENT __________________________________________ 12:15 AM 02 13 00 STS/ISS crew wakeup 12:45 AM 02 13 30 EVA-1: Hygiene break; prebreathe 01:00 AM 02 13 45 EVA-1: Airlock repress 01:30 AM 02 14 15 EVA-1: 10.2 depress 02:05 AM 02 14 50 EVA-1: Campout EVA preps 02:05 AM 02 14 50 SSRMS moves P3/4 to pre-install position 03:25 AM 02 16 10 SSRMS maneuver to "ready to latch" position 03:35 AM 02 16 20 EVA-1: Spacesuit purge 03:50 AM 02 16 35 EVA-1: Spacesuit prebreathe 03:55 AM 02 16 40 P1/P3 bolts engaged 04:40 AM 02 17 25 EVA-1: Crew lock depressurization 04:55 AM 02 17 40 SSRMS ungrapple 05:10 AM 02 17 55 SSRMS moves to viewing position 05:15 AM 02 18 00 EVA-1: Airlock egress; tool setup 05:50 AM 02 18 35 EVA-1: EV1: Connect P1/P3 lower cable tray 05:50 AM 02 18 35 EVA-1: EV2: Release aft solar array blanket box restraint 06:50 AM 02 19 35 EVA-1: EV1: Release aft BGA restraint 06:50 AM 02 19 35 EVA-1: EV2: Release forward solar array blanket box restraint 07:15 AM 02 20 00 ISS: EVA-2 tools configured 07:35 AM 02 20 20 EVA-1: EV1: Solar alpha rotary joint rotate 07:45 AM 02 20 30 EVA-1: EV1: Unstow aft solar array blanket box restraint 07:50 AM 02 20 35 EVA-1: EV2: Release forward BGA restraint 08:15 AM 02 21 00 EVA-1: EV1: SARJ preps 08:15 AM 02 21 00 ISS: Expedition 13 departure preps 08:35 AM 02 21 20 EVA-1: EV2: unstow forward solar array blanket box 08:50 AM 02 21 35 EVA-1: EV1: Connect P1/P3 upper cable tray 09:05 AM 02 21 50 EVA-1: EV2: SARJ prep 10:05 AM 02 22 50 EVA-1: EV1: SARJ prep 10:55 AM 02 23 40 EVA-1: Cleanup 11:35 AM 03 00 20 EVA-1: Airlock ingress/repress 11:50 AM 03 00 35 12A post EVA-1 01:25 PM 03 02 10 EVA-2: Procedures review 02:40 PM 03 03 25 EVA-2: EV3/EV4 campout mask prebreathe 03:25 PM 03 04 10 EVA-2: Crew lock to 10.2 psi 03:45 PM 03 04 30 ISS crew sleep begins 04:15 PM 03 05 00 STS crew sleep begins (EV3/EV4 in airlock)"On EVA 1 we start getting the P3/P4 element ready for solar array deploy," Piper said in a NASA interview. "That happens two days later. The first task [for] that is to hook up the umbilicals. Those are just the power cables and data cables so that the ground can start commanding all of the, the MDMs, the boxes that are on the elements and getting them ready for deploy. Actually one of Joe's tasks is to hook up the umbilicals.
"While he's doing that, I'm starting to remove the launch locks on the solar array blanket boxes. The solar arrays are folded up into what we call blanket boxes. The blanket boxes are attached to a mast canister, which is attached to the four-bar linkage, which is attached to the P4 structure. In order to get that all to fit inside the shuttle bay and also have it be safe for the vibrations of launch there are a number of launch locks and bolts that just hold it all together.
"On EVA 1, I go out and start removing these bolts. The blanket boxes, instead of being out like you see them in all the pictures with the solar arrays deployed, are folded up together. They have big bolts that hold them together so I go out and I start removing all the bolts, first on the aft side and then I go to the forward side. Meanwhile, Joe's done with the umbilicals. He comes out and gets one of the solar arrays ... swings the four-bar out and then he climbs out onto the very end of the mast canister and swings the two blanket boxes out.
"While he's doing that, I'm out on the forward one, and I do the same thing. Now the blanket boxes are pretty much ready for the ground to start commanding them as far as unlatching them and making sure that all the pins that hold them in are all deploy. That gets that ready for the solar array deploys. We're not quite ready to deploy the arrays yet because, in order to get the P3/P4 to fit inside the shuttle bay, we have to have the alpha joint rotated 180 degrees. In order to rotate it back to the zero position, there are two drive mechanisms that needed to be deployed, the DLAs (drive lock assemblies). We start working on those so that they can command the SARJ. That's pretty much what EVA 1 is.
Tanner, his feet anchored in a foot restraint, will mate the first six umbilical cables working at the lower of two cable trays on P3. Piper, meanwhile, will be preparing the solar array wings for deployment, working from a foot restraint on P4 to access two sets of launch restraints, one inboard and one outboard, holding the blanket boxes in place.
Tanner will assist once the first six umbilicals are connected, releasing two restraints securing one of two beta gimbal assemblies. The BGAs are used to control the pitch of the array wings once they are deployed. After the restraints are released, the blanket boxes and the canisters holding the telescoping masts that will extend the array blankets will be rolled into their deploy positions by manually pushing open the four-bar linkages.
After stowing a massive keel pin that helped hold P3/P4 in place in the shuttle's cargo bay, Tanner will move to the mast canisters and rotate the 4A blanket boxes into position, swinging them through an arc of 90 degrees and locking them in place with a strut to hold them in position. Piper will rotate the 2A blanket boxes into place and release the restraints on the other BGA.
Once both sets of blanket boxes are extended in the deploy position, Tanner and Piper will release latches allowing the mast canisters to open. Tanner then will move up to the top of P4 to mate seven umbilical cables while Piper removes thermal covers on the SARJ and repositions one of the two drive lock assembly motors so its gears engage. She also will engage four "stiffeners" needed to provide additional structural support.
With the final set of electrical cables in place, Tanner will make his way up the Z1 truss atop the Unity module to remove a circuit interrupt device, or CID, as a get-ahead task for the next assembly mission. The CIDs act as circuit breakers in the station's electrical system. With CID-6 ion hand, Tanner will float back down the S0 truss and remove CID-8.
After temporarily stowing the two CIDs, Tanner will rejoin Piper and reposition the other DLA to engage its gears. The two DLAs are redundant and either one can drive the rotary joint and the deployed solar arrays.
Before returning to the airlock, Tanner and Piper will remove thermal shrouds around electrical components on the SARJ that are no longer needed.
"The big challenge about that EVA is timing," Tanner told CBS News. "We have to go through our tasks fairly expeditiously, I've got to get that lower tray connected as quickly as I can because that starts a clock on the ground with that 100 pages John McCullough was talking about. They've got to execute many power ups and start talking to the boxes."
Tanner was a good choice for STS-115. He and Atlantis commander Brent Jett flew together on an earlier station assembly mission to attach the P6 solar arrays atop the Z1 truss.
"Deploying the arrays, we've done it before, we know how that should go. I think there's going to be a little bit of a problem on the four bar deploy. On (assembly mission) 4A, we had a problem of them not wanting to go at all and Carlos (Noriega) and I had to push pretty hard just to get them to move and even brought out a special tool to pull them as far as we could. And even with that, two of the latches when we left were not engaged.
"I'm convinced we're not going to have that problem. It's not going to go too fast, it's going to go about two thirds of the way to full deployment but this time the finish will be as easy as pushing it the last little bit. So expect that to happen, I'm not worried about it."
With spacewalk No. 1 complete, astronauts Dan Burbank and MacLean will spend the night inside Quest to prepare their bodies for a second spacewalk Wednesday. The objectives of the second excursion are to release 16 launch locks and six launch restraints to free the SARJ ring mechanism for rotation. Burbank and MacLean also will complete the installation of stiffeners to provide the necessary structural rigidity.
If all goes well, the new solar arrays will be deployed Thursday, stretching 240 feet from tip to tip.
06:45 p.m., 09/11/06, Update: NASA sees no need for additional heat shield inspections; three protruding gap fillers seen but tiles look good
High-resolution photographs of the shuttle Atlantis' underbelly shot today during final approach to the international space station show the orbiter's heat shield tiles are in good shape with no obvious signs of damage.
Agency engineers decided late today that additional heat shield inspections, a move that would have triggered a one-day mission extension, were not required. While NASA could still extend the flight if problems are encountered attaching a new solar array to the space station, the current plan is to stick with the pre-launch timeline.
"The initial report is all the tile on the undersurface of the vehicle looks great," John Shannon, chairman of NASA's Mission Management Team said earlier today.
But analysts did spot three protruding gap fillers, thin spacers between tiles, that worked themselves loose during ascent.
Two of the exposed gap fillers are on the doors covering propellant feedline fittings just behind the main landing gear doors. The gap filler on the port door "is almost gone, it is barely hanging in there by one little corner," Shannon said. "The one on the starboard ET door side looks like it was ripped away, it's a very, very small protrusion."
The third exposed gap filler is located on the port wing and sticks up about .15 inches.
During the first post-Columbia shuttle mission, STS-114, a spacewalking astronaut pulled two protruding gap fillers out to make sure they would not trigger turbulent flow early during re-entry, which can cause higher downstream heating.
Another worrisome gap filler was spotted during Discovery's flight in July on mission STS-121. Located near one of the external tank feedline doors, the gap filler was left in place and while higher downstream heating was observed during entry, it was well within the shuttle's design limits.
Another gap filler was left in place extending above the surrounding tile on one of Discovery's wings. It happened to be located near a temperature sensor, which allowed engineers to improve computer models used to predict the onset of turbulent flow.
"None of these really concern the team a great deal at this time," Shannon said of the three gap fillers noted on Atlantis' belly. "The one on the external tank door is very similar to the one that was cleared on STS-121. The team is going to go through the normal process of looking at that and when it might trip the aerodynamic boundary layer and cause some additional heating.
"The process we honed on STS-121 to understand the impacts, the team will go through that and we'll get a report in subsequent days whether that will be any kind of impact to us. I do not expect it to be."
On Sunday, the astronauts carried out a now-standard close-up inspection of the shuttle's wing leading edge panels and nose cape, the areas that experience the most extreme heating - more than 3,000 degrees Fahrenheit - during re-entry. Shannon said engineers identified 495 "regions of interest."
Of that total, 116 were immediately eliminated because they were present in pre-launch photo documentation. Another 318 were determined to be benign. That left 61 that were still under discussion today, "which might worry you, but what that means is that's just another level of looking at where it is, what kind of heating would happen during re-entry in that area and then deciding whether it was something that needed to be looked at further or not," Shannon said.
Late today, the engineering community decided no additional inspections were needed and that Atlantis' heat shield is in good shape for the trip back to Earth Sept. 20.
Shannon said the numbers were similar to what was observed during the first two post-Columbia missions. The big difference this time around is that NASA's post-launch engineering teams now have flight experience and actual flight data to feed back into the process. The result is a more streamlined operation.
"This is just standard work now," Shannon said. "Things that were a surprise to us on 114 or 121, it's now standard work. From a process standpoint, we're not surprised by any of these things and we know what to go do to analyze it. The other piece that's really critical, we have real flight data now. ... And we found out our models were fairly conservative."
The result is more confidence about flying the shuttle and maintaining flight safety.
"This is a really challenging mission from a space station assembly standpoint," Shannon said. "It was so beneficial to us to fly 114, to fly 121, to see these things, to be able to grapple with them and not have the complications of an assembly mission on top of that.
"We learned so much, we learned how to do it, we learned who needs to know what (and) when, how to hand off data from one group to the next and it's just a very fluid process right now. ... I am very confident in the team and our ability to support the rest of ISS assembly. It's been a good learning experience in the last two flights."
12:00 p.m., 09/11/06, Update: New solar array pulled from shuttle cargo bay; crew set for installation work Tuesday
With only four inches* or so of clearance, astronauts Dan Burbank and Chris Ferguson, operating the shuttle Atlantis' 50-foot-long robot arm, carefully lifted a 35,000-pound solar array truss from the orbiter's cargo bay today, maneuvered it safely past the ship's heat shield inspection boom and out over the shuttle's left wing.
Canadian astronaut Steve MacLean, operating the space station's more massive Canadarm 2 from inside the Destiny laboratory module, then grappled the massive payload in a high-flying handoff, setting the stage for attachment to the station's unfinished solar array truss Tuesday.
"P4 is grappled and there you have it, the great Canadian handshake," MacLean called around 10:50 a.m. Both robot arms were built in Canada and both were critical to today's operation.
A few moments later, the shuttle arm released the 45-foot-long $372 million P3/P4 truss segment, leaving it firmly in the grip of Canadarm 2, perched on the far left end of the station's unfinished truss at an anchor point known as work site 7.
The station's solar array truss runs at right angles to the long axis of the outpost, which is made up of four pressurized modules connected end to end. U.S. and Russian airlock modules are mounted on the right side of that long axis and on the bottom respectively.
The central segment of the truss, attached to the top of the Destiny lab module, is known as S0 for "starboard zero." Two other sections, known as S1 and P1, are attached to the right and left sides of S0 respectively.
The station design originally sported two more segments - S2 and P2 - but they were eliminated earlier in the lab's development.
The new P3/P4 truss segment, made up of a massive rotary joint (P3) and a new set of solar arrays (P4) will remain suspended on the end of the station's robot arm overnight. If all goes well, MacLean and station astronaut Jeff Williams will maneuver it into position just a few inches from the end of the P1 truss early Tuesday
After motorized bolts are engaged to lock P3 to P1, Joe Tanner Heidemarie Stefanyshyn-Piper will begin a complex spacewalk to remove launch restraints and to wire the new segment into the station's power system. That's a critical step, because the new components need station power to operate internal heaters until the new arrays can be deployed later.
"This truss has a lot of electronic components on it, a lot of bits and pieces that we don't want to get cold," said lead flight director Paul Dye. "So we have a clock that's running and we want to be able to get the umbilicals hooked up on the EVA tomorrow in order to make sure we can keep that thing alive and in good shape."
With the completion of the handoff maneuver between the shuttle arm and Canadarm 2, the Atlantis astronauts wrapped up an extremely busy day in space that began with a series of rendezvous rocket firings to catch up with the station, a spectacular end-over-end flip for photography of the shuttle's heat shield and finally, docking with the station.
"It was really spectacular stuff today," said Dye. "The rendezvous this morning was probably just about as perfect as a rendezvous as I have ever been a part of. Everything was just dead on, the timing was great, the tracks were perfect, Brent did a masterful job along with his crew. ... My prop(ulsion) officer was real happy because he said Brent used well below the mean amount of prop that we usually allocate for a rendezvous.
"In general, they docked pretty much on time and that was the only thing they did on time today because everywhere else they've been ahead of sked by a significant amount. ... Again, this is an extremely busy day, one of the fullest days I've ever put together on paper for a mission and they're handling it extremely well."
After a review of the procedures planned for Tuesday's spacewalk, Tanner and Piper plan to seal themselves inside the station's Quest airlock module where they will spend the night at a reduced pressure of 10.2 pounds per square inch to help purge nitrogen from their blood streams.
The so-called "camp out" procedure will save an hour of preparation time and help prevent the bends when the astronauts spend the day in their 5-psi spacesuits. Piper, a former Navy diver, is more familiar than most with the need to guard against decompression sickness.
"One of the things about doing EVAs in space is you have the opposite effect of going diving," she said in a NASA interview. "When you go diving, you go from the EarthÕs atmosphere [atmospheric pressure] to a higher atmosphere and so when you come back up you have to decompress. Well, the same thing happens when you go out on a spacewalk because youÕre inside the space station at 14.7 [pounds per square inch] nominally, and when you go out on your spacewalks, youÕre only down at 4.3 psi.
"WeÕve taken care of that on the space shuttle," she said. "The EVA crew members get locked in the airlock the night before, they bring the pressure in the airlock down to 10.2 psi, and so instead of living in the shuttle at 10.2 youÕre just living in the airlock at 10.2. Since youÕre locked in there, itÕs been given the name of 'camp out', because you have to take your sleeping bags in there and youÕre, in a sense, camping out.
"By doing that, weÕre able to start our EVAs one hour earlier, and so that means now weÕre not crunched at the end of the day. When you come back in from an EVA you have to clean up your suits and put all your tools away, and all of that takes time. What happened in the past is that, that would run into the crew memberÕs sleep time. And we donÕt want to compromise our crews for sleep because thatÕll just lead to fatigue by the end of the mission. So in doing the camp out, if weÕre able to get out the door one hour earlier, then that gives us one more hour at the end of the day so we can finish all of our tasks and not have to run into our sleep period."
The astronauts are scheduled to go to bed at 4:15 p.m. today and wake up at 12:15 a.m. Tuesday to begin spacewalk preparations. If all goes well, Tanner and Piper will exit Quest, after attachment of the P3/P4 truss, around 5:15 a.m. The spacewalk is expected to last about six-and-a-half hours.
A spacewalk by MacLean and Burbank is planned Wednesday to complete activation and checkout of the new truss segment and if all goes well, the giant arrays will be unfurled Thursday, stretching 240 feet from tip to tip. A third spacewalk, by Tanner and Piper, is on tap Friday to carry out communications system upgrades.
* Contrary to what Jett and others told reporters before launch, the actual clearance between the P3/P4 truss and the OBSS sensor boom was about 4.5 inches, engineers said today, not one inch as reported earlier.
08:40 a.m., 09/11/06, Update: Hatches opened; station crew welcomes Atlantis astronauts aboard
The three-man crew of the international space station welcomed the Atlantis astronauts aboard today after a picture-perfect rendezvous and docking.
Atlantis docked with the space station at 6:48 a.m. and, after latches engaged and leak checks were complete, a final hatch was opened around 8:30 a.m. Waiting to welcome shuttle Commander Brent Jett and his crew were Expedition 13 Commander Pavel Vinogradov, flight engineer Jeff Williams and European Space Agency astronaut Thomas Reiter, who was carried to the station in July aboard the shuttle Discovery.
Jett, pilot Chris Ferguson, flight engineer Dan Burbank, Joe Tanner, Canadian astronaut Steve MacLean and Heidemarie Stefanyshyn-Piper floated into the laboratory module and enjoyed a few moments of camaraderie before a safety briefing from the station crew.
Burbank plans to use the shuttle's robot arm later this morning to pull a 35,000-pound solar array truss out of Atlantis' cargo bay so MacLean, operating the station's Canadarm 2 space crane, can grapple it and hold it in place overnight. Early Tuesday, MacLean will attach the P3/P4 truss to the station's P1 truss just before the start of a spacewalk by Tanner and Piper to make critical electrical connections.
Here is a timeline of the rest of today's activity (in EDT and mission elapsed time; subject to change):
EDT DD HH MM EVENT ___________________________________________ 09:25 AM 01 22 10 Shuttle arm (SRMS) unberths P3/4 10:00 AM 01 22 45 Mission status briefing on NASA TV 10:15 AM 01 23 00 EVA tools configured 10:45 AM 01 23 30 SRMS hands P3/P4 to ISS arm (SSRMS) 10:55 AM 01 23 40 SRMS ungrapples P3/4 11:30 AM 02 00 15 EVA camera setup 11:55 AM 02 00 40 EVA-1: Procedures review 02:40 PM 02 03 25 EVA-1: Tanner, Piper campout prebreathe 03:25 PM 02 04 10 EVA-1: 10.2 depress 03:45 PM 02 04 30 ISS crew sleep begins 04:15 PM 02 05 00 STS crew sleep begins
06:50 a.m., 09/11/06, Update: Shuttle Atlantis docks with space station
Commander Brent Jett guided the shuttle Atlantis to a gentle docking with the international space station today after a spectacular end-over-end flip across Africa, Italy and the Balkans to let the lab crew photograph the spaceplane's heat shield.
While the rotational pitch maneuver is a now-standard part of every post-Columbia flight, the lighting today was ideal and video beamed down from the space station provided crystal clear views of the orbiter as it slowly pirouetted some 600 feet below against the backdrop of northern Africa and the Mediterranean Sea.
The smooth flight of the shuttle and the seemingly sedate passage across the Earth below belied the orbiter's five-mile-per second velocity, its open payload bay showing the massive 35,000-pound solar array truss that will be attached to the station Tuesday.
The shuttle's underbelly looked pristine, but engineers will have to wait for the station crew to downlink high resolution digital still images to get the clarity needed to assess the health of the tiles on the belly of the shuttle.
After completing the RPM, Jett guided Atlantis in a slow loop up to a point about 400 feet directly in front of the station with the shuttle's nose pointing toward deep space and its open payload bay toward the lab complex.
From there, flying Atlantis from the aft flight deck, Jett manually guided the shuttle to a docking at 6:48 a.m. as the two spacecraft sailed 220 miles above the south Pacific Ocean west of Chile.
For most shuttle flights, docking would be the highlight of the day. But for Atlantis' crew, there will be no time for celebration. Dan Burbank will use the shuttle's robot arm later this morning to pull the $372 million P3/P4 solar array truss from Atlantis' cargo bay.
After maneuvering the 45-foot-long truss to a point out over the left wing of the shuttle, Burbank plans to hand it off to Canadian astronaut Steve MacLean, operating the station's more powerful Canadarm 2 space crane.
Canadarm 2, anchored to work site 7 on the left end of the station's unfinished solar array truss, will hold the new P3/P4 truss segments in place overnight before installation Tuesday.
04:15 a.m., 09/11/06, Update: Rocket firing begins terminal phase of station rendezvous
The shuttle Atlantis has entered the terminal phase of today's rendezvous with the international space station. Trailing the station by about 9.2 miles, commander Brent Jett and pilot Chris Ferguson fired the shuttle's maneuvering thrusters at 4:08 a.m. to kick off final approach.
03:40 a.m., 09/11/06, Update: MMT debris analysis update
NASA's Mission Management Team has refined the timing of a handful of launch debris events noted during the shuttle Atlantis' climb to space Saturday. As mission managers reported Sunday, no impacts occurred during the first 135 seconds of flight, the period when atmospheric density is high enough to give debris enough energy to cause damage.
Here is the latest MMT summary uplinked to the astronauts by mission control as part of their daily "execute package" of notes and instructions:
"The teams continue to review the ascent imagery data (ET LOX feedline camera, ground cameras, WAVE aircraft video, and debris radar). The preliminary characterization is the debris environment was minimal, which is consistent with the preliminary debris report that you received yesterday during the post insertion timeframe. There was only one event occurring inside the debris sensitive timeframe. That event was a late release of an F4D (thruster jet) Tyvek Cover at (about) 16 secs MET (mission elapsed time) at a velocity of 230 mph."
An attached photo showed the paper cover did not impact the orbiter. Other debris events are as follows (shown in minutes and seconds after launch):
- 2:50 MET- Debris from ET ice Frost ramp at Xt 1270
- 4:05 MET- Possible Orbiter debris impacts to belly and RCC glove areas, but no damage visible. (Q-bar is 0.04 psf)
- 4:07 MET Debris outboard of LO2 feedline that did not impact Orbiter
- 5:27 MET Potential debris impact on starboard wing, but no visible damage, WLEIDS (wing leading edge sensors) did not detect anything
- 5:30 MET RADAR Event with no corroboration from WLEIDS sensors or imagery
- 7:32 MET Debris seen with possible Orbiter impact
- 8:44 MET Suspected ice impacts Orbiter near NLGD (nose landing gear door)
03:00 a.m., 09/11/06, Update: Atlantis closes in on space station
The shuttle Atlantis is closing in on the interational space station this morning for a linkup that will kick off a busy week of work to attach and deploy a $372 million set of solar arrays. Docking is expected around 6:46 a.m.
"Welcome to a wonderful day in micro gravity and thanks for your excellent work!" flight controllers said in a morning message to the crew. "Today your extraterrestrial peers are looking forward to greeting you and to getting your help to upgrade their home! Have a smooth docking!"
Commander Brent Jett is flying a standard rendezvous profile, approaching the lab complex from behind and below. The terminal phase of the rendezvous procedure will begin a few minutes past 4 a.m. with the shuttle trailing the station by about 9.2 miles.
On final approach, at a distance of about 600 feet directly below the station, with Atlantis' nose facing forward and its open payload bay facing the station, Jett will carry out the slow 360-degree rotational pitch maneuver, or RPM, that will point the belly of the shuttle at the station.
As the shuttle's underside rotates into view, Expedition 13 commander Pavel Vinogradov and flight engineer Jeff Williams will photograph Atlantis' belly with handheld digital cameras equipped with 400mm and 800mm lenses. The former has a resolution of three inches while the latter has a resolution of one inch.
Imagery from the station will be downlinked to Houston for detailed analysis.
"The RPM maneuver, or rendezvous pitch maneuver, is actually very visually dramatic," Jett said in a NASA interview. "But from a flying standpoint, it's not really any more difficult than any other type flying we do for rendezvous. The real significance of the RPM is that it allows the station crew to take photos of the underbelly tile areas of the orbiter, which we don't inspect on flight day two. On flight day two, we're looking primarily at leading edge of the wing so this is a whole other area of the thermal protection system, which allows the folks on the ground to analyze for any damage.
"If for some reason we can't do the RPM, it's a significant impact to our mission because we still have to, at some point, go under there and look at the tile. The RPM is a very, very efficient way for us to do a little flip maneuver, as we approach the station and allow the station crew members to use an 800mm lens to photograph all the tile and send it down to the ground and let them analyze it. So it's a real important maneuver."
After completing the pitch-around, Jett will position Atlantis about 400 feet directly ahead of the space station with the shuttle's nose facing deep space and its cargo bay facing the lab complex. He then will guide the spacecraft to a docking with a pressurized mating adaptor attached to the front of the Destiny laboratory module.
After leak checks, Vinogradov, Williams and European Space Agency astronaut Thomas Reiter, ferried to the station aboard Discovery in July, will welcome the Atlantis crew aboard the station and provide a safety briefing before all nine astronauts get down to work.
"Traditionally, space shuttle crews have kind of taken the day off after docking," pilot Chris Ferguson said in a NASA interview. "It's typically a very long and very busy day. They might do some general transfer operations after docking, but they would kind of pause and take the night off and begin the heavy construction the next day.
"What we've elected to do ... is to get right into the payload operations shortly after docking. So about two hours after we're together, hard-mated and the hatches are open, Dan (Burbank) and I are going to extract the payload from the payload bay. Once again, this payload is huge, it occupies the entire payload bay and weighs about 36,000 pounds, so it's no small operation. There are some areas where the clearances get rather tight."
Burbank, operating the arm, will have just one inch of clearance between the P3/P4 solar array truss segment and the OBSS heat shield inspection boom mounted along the right wall of the payload bay. As he is lifting the payload straight up from its perch in the cargo bay, Burbank will have to jog it slightly to the left to avoid the OBSS. It is a delicate procedure because of the payload's inertia and the need to avoid any overshoots that could cause it to hit anything.
Assuming all goes well, Burbank will position P3/P4 over the left wing of the shuttle. At that point, Canadian astronaut Steve MacLean, operating the space station's more massive arm from inside the Destiny laboratory module, will grapple P3/P4 in a handoff maneuver and Burbank will release the truss with the shuttle's arm.
The Canadarm 2 crane will be positioned at work site 7 on the station's P1 truss element, "which is as far as you can go on the space station with the station arm, or Canadarm 2," MacLean said in an interview. "I'm prepositioned so I can accept the handoff. Dan will get it into position and then I'll go in for the handshake when both arms are holding it. Dan will let go and we'll park there over night."
MacLean said the handoff will mark a proud moment for Canada, which provided both robot arms and the Space Vision System that will be used Tuesday to precisely position P3/P4 for attachment to the station's truss.
"Don't be surprised if you hear a call out on the 'great Canadian handshake,'" MacLean joked at a pre-flight news conference. "But we are handshaking with a payload that is impressive, very high tech, that's going to carry us forward to having the best orbiting laboratory in the world."
Pulling P3/P4 from the cargo bay starts a 35-hour timer. That's how long the crew has to get the payload attached to the P1 truss and wired into the electrical system to power critical heaters. But the 13 umbilicals needed to route power and data to and from the new truss element will not be hooked up until Tuesday during a spacewalk by Tanner and Heidemarie Stefanyshyn-Piper.
Instead, P3/P4 will be left hanging out over the left wing of the shuttle Monday night, safely attached to the station's robot arm, while the astronauts wind down from a very busy third day in space.
Here is an updated timeline of today's activities (in EDT and mission elapsed time):
EDT DD HH MM EVENT __________________________________________________ 04:00 AM 01 16 45 ISS: Verify RPM photo setup ready 04:08 AM 01 16 53 TI rendezvous rocket firing 04:20 AM 01 17 05 ISS in attitude 04:44 AM 01 17 29 Sunset 05:07 AM 01 17 52 Range: 10,000 feet 05:15 AM 01 18 00 Range: 5,000 feet 05:17 AM 01 18 02 Sunrise 05:20 AM 01 18 05 Begin final approach 05:21 AM 01 18 06 Range: 3,000 feet 05:25 AM 01 18 10 MC-4 rendezvous burn 05:29 AM 01 18 14 Range: 1,500 feet 05:31 AM 01 18 16 RPM start window open 05:34 AM 01 18 19 Range: 1,000 feet 05:37 AM 01 18 22 KU antenna to low power 05:38 AM 01 18 23 +R bar arrival directly below ISS 05:43 AM 01 18 28 Range: 600 feet 05:45 AM 01 18 30 Rendezvous pitch maneuver 05:46 AM 01 18 31 Noon 05:53 AM 01 18 38 End pitch maneuver 05:54 AM 01 18 39 RPM full window close 05:56 AM 01 18 41 Start pitch up maneuver to +V bar in front of ISS 06:02 AM 01 18 47 RPM start window close 06:07 AM 01 18 52 +V bar arrival; range: 310 feet in front of ISS 06:08 AM 01 18 53 Range: 300 feet 06:12 AM 01 18 57 Range: 250 feet 06:16 AM 01 19 01 Sunset 06:16 AM 01 19 01 Range: 200 feet 06:19 AM 01 19 04 Range: 170 feet 06:21 AM 01 19 06 Range: 150 feet 06:25 AM 01 19 10 Range: 100 feet 06:28 AM 01 19 13 Range: 75 feet 06:32 AM 01 19 17 Range: 50 feet 06:35 AM 01 19 20 Range: 30 feet; start stationkeeping 06:40 AM 01 19 25 End stationkeeping; push to dock 06:45 AM 01 19 30 Range: 10 feet 06:46 AM 01 19 31 Atlantis docks with space station 06:49 AM 01 19 34 Sunrise 07:05 AM 01 19 50 Hatch leak checks 07:20 AM 01 20 05 Group B computer powerdown 07:35 AM 01 20 20 Orbiter docking system preps for entry 07:55 AM 01 20 40 Hatches opened 08:05 AM 01 20 50 Shuttle robot arm (SRMS) grapples P3/P4 08:20 AM 01 21 05 Welcome aboard! 08:30 AM 01 21 15 Safety briefing 08:55 AM 01 21 40 Station arm (SSRMS> configured 08:55 AM 01 21 40 Post-docking EVA transfer 09:25 AM 01 22 10 SRMS unberths P3/4 10:00 AM 01 22 45 Mission status briefing on NASA TV 10:15 AM 01 23 00 EVA tools configured 10:45 AM 01 23 30 SRMS hands P3/P4 to SSRMS 10:55 AM 01 23 40 SRMS ungrapples P3/4 11:30 AM 02 00 15 EVA camera setup 11:55 AM 02 00 40 EVA-1: Procedures review 02:40 PM 02 03 25 EVA-1: Tanner, Piper campout prebreathe 03:25 PM 02 04 10 EVA-1: 10.2 depress 03:45 PM 02 04 30 ISS crew sleep begins 04:15 PM 02 05 00 STS crew sleep begins 05:00 PM 02 05 45 Daily video highlights reel on NASA TV 06:00 PM 02 06 45 Post-MMT status briefing on NASA TVTanner and Piper will spend the night sealed up in the station's Quest airlock module as part of a new "campout" procedure. The airlock's pressure will be lowered from 14.2 pounds per square inch to 10.2 psi to help the spacewalkers purge nitrogen from their blood and prevent the bends when working in their 5-psi spacesuits.
Tuesday morning, after a "hygiene break," Tanner and Piper will begin donning their spacesuits, assisted by Jett. MacLean, meanwhile, will return to the Destiny module, take control of Canadarm 2 and move P3/P4 up to a pre-install position just a few inches from the left end of the station's main truss.
Motor-driven bolts will then engage to lock the new P3/P4 truss in place, clearing the way for Tanner and Piper to begin a critical spacewalk to wire it into the station's electrical system, to remove launch restraints and to begin preparations for solar array deployment Thursday.
06:30 p.m., 09/10/06, Update: NASA has 'high confidence' Atlantis in good shape
An initial assessment of the shuttle Atlantis' heat shield gives mission managers "high confidence" the spaceplane completed its climb to space Sunday without any potentially dangerous debris impacts, officials said today.
John Shannon, chairman of NASA's Mission Management Team for orbital operations, said the results of a detailed analysis of ground imagery, radar data, shuttle inspections, wing leading edge sensor data and photos shot from the space station during final approach Monday will take several more days to complete.
But so far, it would appear what little foam that did fall away from Atlantis' external tank during launch did so well after the shuttle had climbed out of the dense lower atmosphere where debris can attain the energy needed to damage the ship's heat shield.
"We make a decision at the end of our first MMT on whether the thermal protection system is suspect or not," Shannon told reporters today. "And the decision this time is that it is not. That was based on our quick-look review of the imagery, the fact that we had nothing in our aerodynamically sensitive time and the initial look at the leading edge and the nose cap. So right now, I have high confidence in the thermal protection system."
After launch Sunday, engineers identified two potential foam shedding incidents at four minutes and five seconds after liftoff and at five minutes and 28 seconds.
Shannon today showed photographs of the external tank after it was jettisoned in space showing one 4 X 4-inch area of foam loss from an area that had been repaired before flight. A small amount of foam from one of the tank's so-called ice-frost ramps also was missing, along with insulation in two other areas near the tank's cable tray.
NASA currently is redesigning the ice-frost ramps to reduce the amount of foam needed to prevent ice from forming around brackets holding two pressurization lines in place. The ramps are made by pouring foam into molds on top of existing foam and post-Columbia research shows such foam-on-foam buildups are susceptible to cracks.
Even so, Atlantis' tank looked very good to the untrained eye and Shannon said it appeared no foam came off in the time that is the most dangerous, when the surrounding air is dense enough to slow a piece of debris fast enough that the shuttle can slam into it at a high relative velocity.
"We saw no debris at all that came out in our critical time periods," Shannon said. "All the foam we saw lost was after what we call the aerodynamically sensitive transport time that ends at 135 seconds. The first piece of foam we saw come off was after four minutes. So we're in good shape there."
That's not to say engineers don't have interesting data to digest. A C-band radar detected a return from something that apparently separated from the spacecraft 330 seconds after launch. Nothing shows up in camera views and it's not yet clear what might have generated the signature.
In addition, data from wing leading edge sensors detected a 4-G spike just 14 seconds after launch. Again, nothing visible could be seen striking the panels in question. It may simply be the result of leading edge components, which are designed to have a bit of play in them, snapping into place under the stress of launch. A similar spike was seen during Discovery's flight in July, although the magnitude was smaller.
Otherwise, Shannon said, "Atlantis looks great" and flight controllers are only troubleshooting a handful of minor glitches. One of four redundant power channels that drive the shuttle's rudder/speedbrake exhibited unexpected behavior during launch and may need to be isolated for re-entry.
And a few microswitches that indicate whether the payload bay doors are open or closed appear to be stuck, but the astronauts can easily bypass the suspect data. Again, Shannon said, no problems are expected.
And with that, the stage is set for rendezvous and docking with the international space station Monday and the installation of a 35,000-pound $372 million solar array truss that will signal the restart station assembly after a three-and-a-half-year hiatus.
"The bottom line is, we have a really good start to this very complex mission," Shannon said. "The team certainly has their game faces on. They understand the rendezvous tomorrow with the EVA (spacewalk) the day following, it's going to be a really big day for the international space station, it's going to be a very challenging day for the crew and the ground team."
02:00 p.m., 09/10/06, Update: Atlantis heat shield inspection goes smoothly
The Atlantis astronauts inspected the shuttle's wing leading edge panels and nose cap today as part of a now-standard post-Columbia checkout and while additional observations and analysis will take several more days to complete, no obvious signs of damage were seen.
"We've been scanning the vehicle doing the post-ascent inspection," flight director Paul Dye said earlier today. "We finished the starboard wing, finished the nose cap, we're most of the way through the port wing and so far, everything has gone exactly according to plan.
"I think once we get the data down and folks start looking at it, we'll have more to tell you about how things looked. We take the scans and the data needs to be interpreted. But what we've seen looks good so far."
Dye said Commander Brent Jett and his crew also checked out and prepared two spacesuits for use during upcoming spacewalks and carried out a key rendezvous rocket firing to fine-tune the shuttle's approach to the international space station.
"This has been a remarkable shift in the fact that I have not seen a single problem with the vehicle," Dye said. "The crew is ahead of schedule by a measurable amount.
"We did a fairly significant burn this morning, part of our series of burns to catch up with the space station. I anticipate a good on-time docking. There's not much more to say except the crew sounds happy, they sound rested, they're doing great."
The goal of the 116th shuttle mission is to deliver and install a 35,000-pound solar array truss segment on the international space station, a complex task that will require two spacewalks and part of a third to complete.
If all goes well, Jett will guide Atlantis to a docking at a pressurized mating adapter on the front of the U.S. Destiny laboratory module around 6:46 a.m. Monday. The $372 million P3/P4 solar array truss will be pulled from Atlantis' payload bay three-and-a-half hours later and bolted in place Tuesday, followed by the first of three spacewalks.
Here is a look ahead at Monday's schedule (in EDT and mission elapsed time. NOTE: This chart is more current than the flight plan posted on the CBS News STS-115 Quick-Look page. An update to that timeline will be posted shortly):
EDT DD HH MM EVENT ____________________________________________________ MONDAY 12:15 AM 01 13 00 STS/ISS crew wakeup 01:35 AM 01 14 20 Rendezvous timeline begins 02:37 AM 01 15 22 NC4 rendezvous rocket firing 04:08 AM 01 16 53 TI rendezvous rocket firing 04:20 AM 01 17 05 ISS in attitude 04:44 AM 01 17 29 Sunset 04:45 AM 01 17 30 ISS: Verify RPM photo setup ready 05:07 AM 01 17 52 Range: 10,000 feet 05:15 AM 01 18 00 Range: 5,000 feet 05:17 AM 01 18 02 Sunrise 05:21 AM 01 18 06 Range: 3,000 feet 05:25 AM 01 18 10 MC-4 rendezvous burn 05:29 AM 01 18 14 Range: 1,500 feet 05:31 AM 01 18 16 Rotational pitch maneuver (RPM) window open 05:34 AM 01 18 19 Range: 1,000 feet 05:37 AM 01 18 22 KU antenna to low power 05:38 AM 01 18 23 +R bar arrival directly below ISS 05:43 AM 01 18 28 Range: 600 feet 05:45 AM 01 18 30 Start RPM maneuver 05:46 AM 01 18 31 Noon 05:53 AM 01 18 38 End RPM maneuver 05:54 AM 01 18 39 RPM window close 05:56 AM 01 18 41 Initiate pitch up maneuver 06:02 AM 01 18 47 RPM start window close 06:07 AM 01 18 52 +V bar arrival; range: 310 feet in front of ISS 06:08 AM 01 18 53 Range: 300 feet 06:12 AM 01 18 57 Range: 250 feet 06:16 AM 01 19 01 Sunset 06:16 AM 01 19 01 Range: 200 feet 06:19 AM 01 19 04 Range: 170 feet 06:21 AM 01 19 06 Range: 150 feet 06:25 AM 01 19 10 Range: 100 feet 06:28 AM 01 19 13 Range: 75 feet 06:32 AM 01 19 17 Range: 50 feet 06:35 AM 01 19 20 Range: 30 feet; start stationkeeping 06:40 AM 01 19 25 End stationkeeping; push to dock 06:45 AM 01 19 30 Range: 10 feet 06:46 AM 01 19 31 ATLANTIS DOCKS WITH SPACE STATION 06:49 AM 01 19 34 Sunrise 07:52 AM 01 20 37 Hatches opened 08:02 AM 01 20 47 Shuttle robot arm grapples P3/P4 08:20 AM 01 21 05 Welcome aboard! 09:18 AM 01 22 03 Shuttle arm unberths P3/P4 10:00 AM 01 22 45 Mission status briefing on NASA TV 10:42 AM 01 23 27 Shuttle arm hands P3/P4 to station arm 01:57 PM 02 02 42 Tanner, Piper begin airlock campout 03:45 PM 02 04 30 ISS crew sleep begins 04:15 PM 02 05 00 STS crew sleep begins 05:00 PM 02 05 45 Daily video highlights reel on NASA TV 06:00 PM 02 06 45 Post-MMT briefing on NASA TV
04:45 a.m., 09/10/06, Update: Astronauts gear up for heat shield inspection
The Atlantis astronauts are gearing up to carry out a detailed inspection of the shuttle's wing leading edge panels and nose cap, part of a now-standard flight-day-two checkout to verify the integrity of the ship's heat shield.
An updated flight plan and a rendezvous and docking timeline are now posted on the CBS News STS-115 Quick-Look page. Here is an updated timeline of today's activities (in EDT and mission elapsed time):
09/10/06 DATE/EDT DD HH MM EVENT __________________________________________________________ Sun 01:15 AM 00 14 00 Crew wakeup Sun 02:45 AM 00 15 30 PGSC setup (part 2) Sun 03:09 AM 00 15 54 NC2 rendezvous rocket firing Sun 03:45 AM 00 16 30 TV setup Sun 03:45 AM 00 16 30 Robot arm unberth Sun 05:00 AM 00 17 45 Starboard wing survey Sun 05:15 AM 00 18 00 Spacesuit checkout preps Sun 05:45 AM 00 18 30 Spacesuit checkout Sun 06:30 AM 00 19 15 Nose cap survey Sun 06:50 AM 00 19 35 OMS pod inspection Sun 07:15 AM 00 20 00 Crew meals begin Sun 08:15 AM 00 21 00 EVA prep for transfer Sun 09:00 AM 00 21 45 Port wing survey Sun 10:15 AM 00 23 00 Transfer preps Sun 10:30 AM 00 23 15 OBSS berthing Sun 11:15 AM 01 00 00 Upper surface survey Sun 12:00 PM 01 00 45 Centerline camera installation Sun 12:15 PM 01 01 00 Rendezvous tools checkout Sun 12:30 PM 01 01 15 Orbiter docking system ring extension Sun 01:55 PM 01 02 40 Laser dynamic range imager (LDRI) downlink Sun 02:29 PM 01 03 14 NC3 rendezvous rocket firing Sun 04:15 PM 01 05 00 Crew sleep begins
05:00 p.m., 09/09/06, Update: Ascent debris appears minimal; no damage seen
A camera mounted on the side of the shuttle Atlantis' external tank showed several pieces of foam insulation separating from the tank about four minutes after liftoff and again a minute and a half later. But that was well above the denser atmospheric regions where debris poses a major threat to the shuttle's heat shield, officials said. In any case, there were no immediate signs of any damage.
"The bottom line is, we are looking at nits, nothing of any remote consequence," shuttle Program Manager Wayne Hale told reporters at a quick-look imagery news conference.
"The reason I don't have any pictures for you is there's just nothing to look at here, folks," he said. "Of course, we will inspect the underside of the orbiter, the entire heat shield system with a fine tooth comb and prove there is nothing that caused any damage."
Hale said four debris events were noticed in ascent video and radar data. Two were foam incidents at four minutes and five seconds into flight and again at five minutes 28 seconds after launch. A piece of ice detached after external tank separation that struck the orbiter near its nose landing gear doors, but that happened as the shuttle was slipping into orbit and no damage was seen.
Radar tracking indicated a possible debris event around the five-minute 40-second mark, but engineers don't yet know what that might have been. In addition, a paper rain cover used to protect a maneuvering rocket nozzle before launch failed to separate as early as desired, but it did not appear to strike the orbiter.
In all cases, Hale said, initial examination of ascent video revealed no signs of any damage to the shuttle's heat shield.
For foam debris to pose a threat to the shuttle's tiles or wing leading edge panels, it must come off early in flight when the shuttle is still within the denser regions of the atmosphere. That can cause separated foam to decelerate very rapidly, allowing the shuttle to ram into it at a high relative velocity. After about two minutes and 15 seconds, the shuttle is beyond that danger zone.
The video showed the tank's externally mounted 17-inch-wide liquid oxygen feedline flexing a fair amount as the shuttle thundered away. But Hale said the movement was normal and that it was not related to Atlantis' so-called high-Q ascent, which subjected the shuttle to higher aerodynamic stress.
Engineers will need several days to evaluate footage from a variety of cameras, data from wing leading edge sensors, a detailed inspection by the astronauts Sunday and additional inspections Monday during final approach to the station before Atlantis will be given a clean bill of health.
In the meantime, "what you saw today was a flawless count, a majestic launch and it was tough to get here," said NASA Administrator Mike Griffin. "This vehicle has not flown in many years and not everything in the count leading up to this day was easy. And in between we had to dodge tropical storms, lightning strikes and things like that. But we got here and it was just a flawless day."
11:35 a.m., 09/09/06, Update: Atlantis rockets into space UPDATED at 12:45 p.m. with quotes from post-launch news conference
The space shuttle Atlantis took off today on its fifth try, kicking off a long-awaited flight to restart assembly of the international space station three years after the Columbia disaster derailed construction.
Considered one of the most complex flights in shuttle history, commander Brent Jett and his five crewmates, with help from the station's three-man crew, will attach a 35,000-pound 45-foot-long solar array truss to the lab complex and stage three spacewalks to make critical electrical connections, hook up the array's cooling system and deploy the giant panels.
"In my opinion, every one of these flights we're flying in the next 12 to 18 months ranks right up there as the most complicated flights we've every flown, including Hubble Space Telescope repair missions," said Paul Hill, mission operations manager at the Johnson Space Center.
"The fact that we're going to go conduct a series of them for 18 months, each one of which is absolutely necessary for the next one to happen, without a doubt makes this the most complicated, most complex 18 months of manned spaceflight we have ever experienced.
Said shuttle Program Manager Wayne Hale: "Clearly these are the most complicated spacewalk and assembly tasks that have ever been done before."
Two weeks after being grounded by a launch pad lightning strike, tropical storm Ernesto, a fuel cell glitch and trouble with an external tank fuel sensor, Atlantis's main engines flashed to life on time, followed 6.6 seconds later by ignition of the shuttle's twin solid-fuel boosters at 11:14:55 a.m.
With a crackling burst of incandescent flame, Atlantis began accelerating skyward, hitting 120 mph in just 10 seconds and then rolling about its long axis to line up on a trajectory carrying it up the East Coast of the United States.
A launch try Friday was called off because one of four hydrogen low-level engine cutoff - ECO - sensors manfunctioned. NASA managers decided to press ahead today using an amended flight rule that permitted a launch if the other three sensors worked properly. As it turned out, ECO sensor No. 3 worked normally today and the malfunction Friday remains an unexplained anomaly.
"Brent, it looks like you're long wait is over," Launch Director Mike Leinbach radioed the crew a few minutes before liftoff. "We wish you all the best luck in the world, Godspeed, and we'll see you back here in about two weeks."
"We appreciate those words and the effort to make this launch window," Jett replied. "It's been almost four years, two return to flight missions, a tremendous amount of work by thousands of individuals to get the shuttle program back to where we are right now and that's on the verge of restarting the station assembly sequence.
"We're confident over the next few weeks, and few years for that matter, that NASA's going to prove to our nation, to our partners and our friends around the world that it was worth the wait and the sacrifice. We're ready to get to work."
Atlantis put on a spectacular Saturday skyshow as it climbed away from Florida's space coast atop a long cloud of churning exhaust, knifing through a partly cloudy sky. A camera mounted on the external fuel tank provided dramatic live views as the shuttle climbed toward space, showing the Florida coast line dropping away in the brackground as the ship arced out over the Atlantic Ocean.
"What you saw today was a flawless count, a majestic launch and it was tough to get here," said NASA Administrator Mike Griffin. "This vehicle has not flown in many years and not everything in the count leading up to this day was easy. And in between we had to dodge tropical storms, lightning strikes and things like that. But we got here and it was just a flawless day."
Atlantis made the climb to orbit using an external tank featuring so-called ice-frost ramps that are officially classified as "probable/catastrophic" in NASA's risk matrix, meaning there is a 50-50 chance of a catastrophic failure over the 100-flight life of a space shuttle.
NASA is in the process of redesigning the ice-frost ramps but an interim fix will not be available until next year and the shuttle Discovery will make another flight with the old design in December.
Reviewing launch video in slow motion, reporters could see several pieces of what appeared to be foam insulation separating from the external tank about four minutes after liftoff. But that was well above the denser atmospheric regions where debris poses a major threat to the shuttle's heat shield. In any case, there were no obvious signs of damage.
"It's extremely preliminary but so far, we didn't see anything in the region of highest concern and the things that folks did see ... were well into the ascent phase where we really don't have debris concerns," said LeRoy Cain, chairman of the launch-site Mission Management Team.
The video also showed the tank's externally mounted 17-inch-wide liquid oxygen feedline flexing a fair amount as the shuttle thundered away. A foam ramp that used to provide aerodynamic shielding was removed to eliminate a potential source of ascent debris. The oxygen line appeared to move more than one used during Discovery's launch in July, but Atlantis made a so-called high-Q ascent that subjected the shuttle to higher aerodynamic loads. Whether that played any role in the movement of the oxygen line it not yet known.
But engineers will need several days to evaluate footage from a variety of cameras, data from wing leading edge sensors, a detailed inspection by the astronauts Sunday and additional inspections Monday during final approach to the station before Atlantis will be given a clean bill of health.
Joining Jett and Ferguson aboard Atlantis were flight engineer Dan Burbank, Joe Tanner, Canadian astronaut Steve MacLean and Heidemarie Stefanyshyn-Piper.
The solar alpha rotary joint, or SARJ, is the main component of what NASA calls the P3, or port 3, truss element. The solar arrays, their electronics and cooling radiators make up the P4 truss element. Both are bolted together and NASA refers to the combination as the P3/P4 truss.
Getting P3/P4 attached to the station's port truss will require one of the most ambitious flight plans ever put together for a shuttle mission.
Atlantis will dock with the space station Monday around 6:45 a.m. Just two hours later, Burbank, operating the shuttle's robot arm, will lift the P3/P4 truss out of the cargo bay and hand it off to MacLean, who will be operating the station's more massive Canadarm 2. Canadarm 2 will be mounted atop a mobile transporter on the far end of the port truss.
"Normally, once we finish the rendezvous, we open the hatches, everybody says hello and we get down to doing some (equipment and supply) transfers and a few things like that," said lead shuttle flight director Paul Dye. "We have so much on this mission that on this day, we're going to do the rendezvous and then we're going to ... take the payload, the P3/P4 truss segment, out of the bay and hand it off to the station before the crew goes to bed.
"So while we are equalizing air pressure between the spacecraft and opening the hatches and getting things connected and shaking hands and greeting, we're going to have crew on the aft flight deck getting ready to pull the P3 out."
Because the 50-foot-long orbiter boom sensor system, or OBSS, will be in place along the right side of Atlantis' payload bay, Burbank will have about one inch of clearance as he unberths P3/P4. To get past the OBSS, he will have to move the arm in a complex sequence, being careful not to bang into anything along the way.
"We'll grapple the payload, we'll move it up, back a little bit, up a little bit more to where we're clear, then out to the side and then we have a large automated maneuver which will put it into what we call the handoff position so the station can go and grab that with the big arm," Dye said.
"This is a pretty significant activity by itself and putting it on rendezvous day makes this a pretty long and very interesting day. Once we have it held in the handoff position, the station arm will move in and grapple. Once they've got it, we'll release it with our arm and at that point, it becomes (the station's) piece of equipment."
MacLean will leave P3/P4 parked overnight on the left side of the shuttle just below the station's unfinished truss. Before the crew goes to bed, they will change the orientation of the shuttle-station complex, rolling 45 degrees to port. That will aim the left side of the truss down toward Earth and help keep the stowed solar array blankets warm.
The next day, MacLean will move P3/P4 up to the station's P1 truss (there is no P2 element). Once properly aligned, motorized bolts in P1 will be powered up to lock the new truss in place.
As soon as three of the four attachment bolts are engaged, Tanner and Piper will exit the station's Quest airlock and begin a complex spacewalk to make critical electrical connections required to power heaters and other systems necessary to keep the new arrays alive.
Electrical power to the U.S. section of the space station currently is provided by solar arrays mounted atop a short truss, known as Z1, that extends up in the zenith direction from the station's multi-hatch Unity module.
Those arrays, known as P6, will be moved down to the main solar array truss next year and attached to a short spacer, known as P5, that will be bolted to P4 during the next shuttle assembly mission in December.
To wire in the new P4 arrays, flight controllers in Houston will carefully power down the station's two P6 electrical channels, one at a time, so Tanner can hook up 13 umbilical cables between P1 and P3/P4.
"There are about a hundred pages of ground commanding that have to go on in order to get things powered down in the right order and get things switched over and powered back up again afterwards," station flight director John McCullough said in an interview. "It's one of the more tightly choreographed EVAs that we've done as far as ground and crew interaction."
The P4 solar arrays are packed up like venetian blinds in four large "blanket boxes." Tanner and Piper will prepare those boxes for deployment and start the process of readying the SARJ for operation.
NASA managers may insert an extension day after the first spacewalk to give the astronauts time to carry out additional heat shield inspections if any "areas of interest" are identified during the inspections Thursday or during final approach to the station.
But as it now stands, MacLean and Burbank will carry out a second spacewalk the day after the first to complete preparations for SARJ operation and solar array deploy. That night, flight controllers will send commands to extend the arrays one mast bay in a confidence test before the astronauts take over the next morning. First, they will extend each array to 49 percent and then, after letting the sun heat them up a bit, the rest of the way.
The stepwise approach is being taken because of problems encountered in December 2000 when the P6 array was deployed. When the first P6 wing unfurled, several solar cell panels stuck together, resulting in a jerky motion that caused a tension cable to unwind and jump from its spool.
The second P6 array was deployed in high-tension mode, which prevented additional problems. Engineers now believe the "stiction" was caused by subtle effects of atomic oxygen coating the arrays and low temperatures. For the P3/P4 deploy, the arrays will be extended in high-tension mode with enough solar heating to preclude similar problems.
Fully extended, the 38-foot-wide arrays will span 240 feet from tip to tip. Some 66,000 solar array cells will generate nearly 66 kilowatts of usable power. A dozen massive batteries will provide power when the station moves into Earth's shadow and ammonia lines inside accordion-like radiator panels extending 44 feet will shed the heat generated by the electrical circuits.
But the new arrays will not provide power to the station until the next shuttle mission in December when the left side of the P6 array is retracted. In its current position, the port wing of the P6 array is at right angles to the P4 wings, extending into the area where P4 eventually will rotate.
With the new arrays deployed, Tanner and Piper will stage a third spacewalk the following day to complete SARJ activation, to carry out critical repairs on the station's S-band antenna system and to install a thermal blanket around components of the lab's high-speed KU-band antenna.
If all goes well, Atlantis will undock from the space station Sept. 17 - Sept. 18 if the flight is extended a day. The next day, the crew will carry out heat shield inspections to make sure Atlantis hasn't been hit by any orbital debris or micrometeoroids since they carried out a post-launch inspection on the second day of the mission.
Landing back at the Kennedy Space Center is targeted for a few minutes before 6 a.m. on Sept. 20, Sept. 21 if the flight is extended. Assuming the shuttle's external tank performed well and no major impact damage occurs, NASA managers will relax a post-Columbia requirement to launch in daylight, opening up more space station launch windows and clearing the way for a night launch of Discovery Dec. 14.
09:10 a.m., 09/09/06, Update: Astronauts strapped in; ECO 3 working normally
The Atlantis astronauts have strapped in for launch. The forecast remains favorable and there are no technical problems at pad 39B.
An engine cutoff - ECO - sensor that failed to operate properly during a launch try Friday appears to be working normally today, as are the other three ECO sensors in the hydrogen section of the shuttle's external tank.
If ECO sensor No. 3 fails computer checks at any point today, NASA will press ahead with a flight rule exception permitting launch with three of four operational sensors. But as of this writing, the sensor is operating normally.
It is not clear what, if any, additional data engineers have today about the cause of the original ECO 3 malfunction that they didn't have Friday or whether the readings today are considered reliable.
07:40 a.m., 09/09/06, Update: Astronauts depart crew quarters
Commander Brent Jett, pilot Chris Ferguson, flight engineer Dan Burbank, Joe Tanner, Canadian astronaut Steve MacLean and Heidemarie Stefanyshyn-Piper departed crew quarters and headed for launch pad 39B today to strap in for blastoff on a space station assembly mission.
The 116th shuttle mission remains scheduled for 11:14:55 a.m., the final opportunity in the current launch window. If Atlantis doesn't get off the ground today, the flight will slip to around Sept. 30 at the earliest, and that assumes NASA waives a daylight launch requirement. If not, launch would slip to around Oct. 26.
But there are no technical problems of any significance at pad 39B and forecasters continue to predict good weather. Atlantis' external tank is loaded with rocket fuel and three of the four hydrogen engine cutoff - ECO - sensors at the bottom of the tank are operating normally. The failure of a single sensor - ECO 3 - forced a launch scrub Friday but engineers believe the other three will work correctly.
02:30 a.m., 09/03/06, Update: Shuttle refueled for second launch try; ECO sensors performing as expected
Engineers at the Kennedy Space Center began refueling the shuttle Atlantis early today for a down-to-the-wire attempt to get the oft-delayed space station assembly mission off the ground before its current launch window closes.
Supercold liquid oxygen and hydrogen rocket fuel began flowing toward the shuttle from huge dewars near the pad at 1:15 a.m., setting the stage for launch at 11:14:55 a.m. Forecasters are predicting good weather, although there's a chance of showers within 20 nautical miles.
Today's launch will depend on the performance of three engine cutoff - ECO - sensors at the bottom of the shuttle's huge external tank. During fueling Friday, one of four such sensors malfunctioned and indicated it was wet when it should have indicated dry. That forced a 24-hour launch scrub.
NASA's launch commit criteria require all four sensors to be operating normally for a countdown to proceed. In the case of a single sensor that "fails wet," managers can approve launch the next day if the other three sensors continue to operate as expected and no other sensor issues develop.
Hydrogen ECO sensor No. 3 failed wet Friday and continued to indicate it was wet until five hours after the tank was drained, when it finally toggled dry. The other three sensors went dry when they were supposed to. ECO-3 is considered failed.
Early today, the presumably healthy sensors indicated they were wet, as expected, when they were covered by liquid hydrogen. Computer commands then were sent to simulate a dry condition and again, ECO sensors 1, 2 and 4 operated normally.
The ECO sensors are part of a backup system designed to prevent the shuttle's main engines from running too long and draining the tank, with potentially catastrophic results, if other problems force the engines to run longer than expected.
Three sensors would have to fail wet to compromise the system, misleading the shuttle's flight computers into believing propellant remained in the tank when, in fact, it was empty. In the wake of problems with ECO sensors before the first post-Columbia mission last year, NASA managers developed a rationale for flying with three of four sensors if a single sensor failed wet and no other ECO system problems developed during a second launch attempt.
04:30 p.m., 09/08/06, Update: Suspect ECO sensor stays wet after tank drained; other sensors indicate dry as expected
Engine cutoff - ECO - sensor No. 3, the one that "failed wet" earlier today and derailed an attempt to launch the shuttle Atlantis, continued indicating it was immersed in liquid hydrogen after the ship's external tank was drained this afternoon, officials said. The other three ECO sensors in the hydrogen tank correctly indicated they were dry as one would expect.
The readings lend some credence to the belief that three of the four sensors are operating normally. If they continue to behave properly when the tank is re-loaded with liquid hydrogen early Saturday - and if no other sensor issues develop - NASA managers may be able to approve a flight rule waiver allowing a launch with three of four operational ECO sensors.
At launch pad 39B, meanwhile, approaching bad weather will prevent engineers from moving a gantry back in place around Atlantis. As a result, technicians will be unable to re-install a rain cover over one of the ship's forward thrusters that was blown off during a recent storm.
Water in the thruster can freeze as the shuttle climbs to space and interfere with operation of a pressure sensor. That, in turn, can fool the shuttle's computers into believing the thruster failed. But the thruster in question points to one side, not straight up, and engineers are hopeful any rain showers later today will not cause problems.
04:00 p.m., 09/08/06, Update: Launch delayed by ECO sensor failure; Hale says team made right decision
After a dramatic, down-to-the-wire debate, NASA's Mission Management Team called off the shuttle Atlantis' countdown today and delayed launch at least 24 hours because of concern about an apparently faulty low-level hydrogen fuel sensor in the ship's huge external tank.
"OK, Brent, we gave a lot of thought to the ECO sensor issue today and what we decided to do as a team is follow the launch commit criteria as written. And so we're going to detank this vehicle, come back in tomorrow, fill it back up and see how they behave and see if we can get more confidence in that system for tomorrow's attempt," Launch Director Mike Leinbach told commander Brent Jett and his five crewmates during a final "hold" at the T-minus nine-minute mark.
"So we appreciate you guys getting on board today," Leinbach said. "Tomorrow's weather should be just as good as it was today if not better. We all feel good about the attempt today, we didn't get there because of the ECO sensors."
"OK, Mike, we understand and we concur 100 percent," Jett replied from Atlantis' flight deck. "That whole plan was given a lot of thought by a lot of smart people, under not having the pressure of a vehicle on the pad. So it's the right thing to do."
The launch time Saturday is 11:14:55 a.m. and forecasters are predicting an 80 percent chance of good weather. At issue is whether Atlantis can be cleared for flight with three out of four hydrogen main engine cutoff - ECO - sensors operating. The sensors are part of a critical backup system intended to make sure the shuttle's main engines don't shut down early or run too long.
Problems with ECO sensors bedeviled NASA last year during the ramp up to the first post-Columbia mission, prompting one scrub and intense analysis. After the flight, engineers traced the problem to a suspect connection between sensors and electrical cables in a specific batch of ECO sensors manufactured in the late 1990s.
The sensors in a tank used by the shuttle Discovery last month were replaced with a set thought to be fault free and those sensors worked as expected. The sensors in Atlantis' tank also were replaced after detailed inspections identified the best available sensors.
It is not yet clear whether the problem seen today, when hydrogen ECO sensor No. 3 "failed wet," involved the sensor, its wiring or an avionics box aboard the shuttle that reformats and routes the data to flight computers.
But the timing of the failure indicates it more likely involves the sensor itself and not electronics aboard the shuttle. And when the hydrogen section of the tank was drained today, ECO sensor No. 3 continued indicating it was wet when the other sensors switched back to dry as expected.
Twenty four propellant sensors are used in the shuttle's external tank, 12 each in the oxygen and hydrogen sections. Eight are used in each tank to measure the amount of propellant present before launch. Four ECO sensors in each tank are used in flight as part of a backup system intended to make sure the ship's engines don't shut down too early, resulting in an abort, or run too long, draining the tank dry with potentially catastrophic results.
NASA's original launch commit criteria required three operational ECO sensors for a countdown to proceed. But in the wake of the 1986 Challenger disaster, the LCC was amended to four-of-four because of concerns two sensors could be knocked out by a single failure in an upstream electronic black box known as a multiplexer-demultiplexer. The single-point failure later was corrected, but the four-of-four launch rule remained on the books.
Because of ECO sensor problems going into me first post-Columbia mission, NASA managers ultimately developed an "exception" to the four-of-four rule that would permit a launch if A) a hydrogen sensor failed wet; and B) engineers could show the problem didn't originate in the multiplexer-demultiplexer avionics system.
As originally written, the flight rule exception called for standing down a day. A second launch try could then be made depending on an analysis of the way the sensor failed and how it behaved during a second fueling. With one sensor failed wet, two more ECO sensors would have to fail wet to pose the threat of running the tank dry.
Many observers were surprised NASA's Mission Management Team held open the option of launching today for so long. The flight rule was intended to give engineers a way to press ahead with a launch in the case of a single sensor failure, but only after taking time to make a thorough analysis, away from the pressure of a launch countdown.
Asked why NASA pressed so hard today, shuttle Program Manager Wayne Hale seemed surprised the question was asked.
"What are we going to do, go look for a tee time? I mean we are here to launch the vehicle, so it always, always makes sense to look at the situation you've got. Now, you do that with a great deal of trepidation ... because you're in the heat of the launch and you can get carried away by emotion.
"There's no point in knocking it off early, even though coming in the door this morning, most of us thought we were not going to launch today," Hale said. "So I'm not a bit surprised that's the way it turned out."
It seemed to be a close thing, however. Sources said the majority of the engineering community favored pressing ahead with launch. But a representative of the flight crew operations directorate at the Johnson Space Center voted against proceeding. Other non-voting engineers and mangers also voiced reluctance to proceed.
In the end, Mission Management Team Chairman LeRoy Cain called off the countdown.
"In this case, this engine cutoff sensor No. 3 failed to what we call a wet condition," he said. "And for that condition, we had previously established launch commit criteria that said if we had one of the four sensors fail that way , we would detank, come back the next day and retank, and evaluate the situation as to whether or not there were any changes and whether we'd be safe to fly. That is exactly the case we had today.
"At the end of the day, we had some folks who did not feel like we should press on and launch today and that we should follow the procedure we had previously established, for good reason. So we decided that was the approach we'd take."
The behavior of the three presumably good ECO sensors will be critical to any decision to launch Saturday.
"Overnight, the engineers are going to look very carefully at how all the other sensors look during the detanking when they go dry," Hale said. "And if everything is performing as we expect, and if we just have one sensor continue to be a bad actor, we'll launch tomorrow."
While engineers were close to developing a technical rationale for flying today, "we felt it was more prudent to do what we had planned to do in our calmer moments and review the data," Hale said. "We'll be back tomorrow. The weather's probably going to be good for us tomorrow and we'll give it another shot and hopefully, be successful."
If the shuttle doesn't get off the ground Saturday, the long-awaited and oft-delayed mission almost certainly will slip to late this month - or next - because of a daylight launch constraint and conflict with a Russian mission to rotate crews on the international space station.
A launch past Saturday is not believed to be an option. NASA presumably could launch after a Soyuz carrying the returning station crew lands Sept. 28. But that would require managers to relax a current requirement to launch in daylight for photo documentation of the shuttle's external tank and heat shield.
The next lighted launch opportunity after Saturday is Oct. 26. But Hale would not speculate on how all of that might play out, saying only that he expected to launch Saturday.
09:55 a.m., 09/08/06, Update: ECO sensor discussion ongoing; crew on board
Editor's Note...
The Atlantis astronauts are strapped in aboard the shuttle as the countdown enters is final 90 minutes. NASA managers are continuing to discuss problems with one of four engine cutoff - ECO - sensors in the shuttle's external tank and a final decision on whether to proceed toward a launch at 11:40:37 a.m. today or scrub for 24 hours has not yet been made.
The forecast continues to call for good weather. While the ECO sensor discussion has dominated events this morning, engineers also are discussing the loss of a maneuvering jet thruster cover that may have allowed water from recent showers to enter a nozzle. The concern is that ice could form that might pose a debris threat during ascent.
There are no other issues of any significance.
08:15 a.m., 09/08/06, Update: Astronauts begin boarding; ECO sensor discussion continues
Atlantis commander Brent Jett, pilot Chris Ferguson, flight engineer Dan Burbank, Joe Tanner, Canadian astronaut Steve MacLean and Heidemarie Stefanyshyn-Piper have arrived at launch pad 39B to strap in for blastoff today on a space station assembly mission.
Liftoff remains targeted for 11:40:37 a.m. and the forecast calls for generally favorable conditions.
NASA's Mission Management Team continues a discussion about the potential impact of a hydrogen low-level fuel sensor in the shuttle's external tank that suffered a malfunctioned earlier today. An existing flight rule would seem to require a 24-hour launch delay, but engineers are debating whether they can press ahead for launch today as is.
An update will be posted here as soon as a decision is made.
06:30 a.m., 09/08/06, Update: NASA managers mull ECO options
NASA managers are mulling two options for dealing with the failure of a hydrogen fuel level sensor in the shuttle Atlantis' external tank: Flying as is today or standing down for 24 hours for additional troubleshooting.
Engine cutoff - ECO - sensor No. 3 in the base of the hydrogen section of the huge external tank apparently "failed wet" early today during a test. Computer commands were sent to simulate a dry condition as part of a now-standard health check and the sensor continued to indicate wet.
Twenty four propellant sensors are used in the shuttle's external tank, 12 each in the oxygen and hydrogen sections. Eight are used in each tank to measure the amount of propellant present before launch. Four ECO sensors in each tank are part of a backup system intended to make sure the ship's engines don't shut down too early, resulting in an abort, or run too long, draining the tank dry with potentially catastrophic results.
NASA's original launch commit criteria required three operational ECO sensors for a countdown to proceed. But in the wake of the 1986 Challenger disaster, the LCC was amended to four-of-four because of concerns two sensors could be knocked out by a single failure in an upstream electronic black box known as a multiplexer-demultiplexer. The single-point failure later was corrected, but the four-of-four launch rule remained on the books.
Because of ECO sensor problems going into me first post-Columbia mission, NASA managers ultimately developed an "exception" to the four-of-four rule that would permit a launch if A) a hydrogen sensor failed wet; and B) engineers could show the problem didn't originate in the multiplexer-demultiplexer avionics system.
As originally written, the flight rule exception called for standing down a day and if, during a second launch try, the same electronic "signature" was seen, the team could proceed with launch. Because of the way the system works, two more ECO sensors would have to fail wet to pose the threat of running the tank dry.
NASA managers today apparently are considering yet another change to the ECO sensor rationale. The problem is particularly vexing because Atlantis' tank is equipped with ECO sensors that underwent extensive inspections before installation.
Here is a bit of background for readers unfamiliar with the ECO sensor system.
The cutoff sensors are armed late in the ascent when a relatively small amount of rocket fuel remains in the tank. Once armed, the shuttle's computer system checks the status of each sensor, which is still immersed in cryogenic propellant, to make sure it is "wet." To protect against a faulty sensor, the first "dry" indication from any one of them is discarded.
During normal operations, the shuttle's flight computers continuously calculate the orbiter's position and velocity, using that data to figure out when the engines should be shut down to achieve the desired target. As a backup, the computers also monitor the ECO sensors as the tank empties to protect against unexpected problems that might affect the performance of the propulsion system.
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The shuttle is launched with more fuel than it needs and in normal operation, the ECO sensors would never be "dry" before the normal guidance-based engine shutdown sequence begins. But if a problem does occur, and the computers detect two "dry" sensors, they will shut the engines down to keep from running the tank dry. As long as at least three sensors indicate "wet," however, fuel is assumed to be in the tank and the engines will keep running.
Once the system is armed, two sensors must fail "dry" to trigger an inadvertent engine shutdown. If three sensors fail "wet," the engines could run the tank empty.
The odds of such multiple failures are "extremely remote," according to internal NASA documents describing earlier problems. In fact, no cutoff sensors have failed in flight since the sixth shuttle mission in 1983 when the design was changed.
But the consequences of an early or late engine shutdown are extreme. A premature shutdown could prevent a crew from reaching orbit while a late shutdown could result in an engine fire or explosion. Even though the cutoff sensor system is considered a backup to the shuttle's flight computers, NASA's post-Challenger launch commit criteria required four operational cutoff sensors in each tank to provide multiple layers of redundancy.
The engine cutoff sensor system has been put to the test only two times in the history of the shuttle program.
During the shuttle Challenger's launching July 29, 1985, on mission STS-51F, a main engine shut down five minutes and 43 seconds after blastoff because of an internal temperature sensor failure. The fuel consumption of the two engines that kept running was affected and the end result was an ECO sensor engine cutoff.
The only other such shutdown in shuttle history occurred during mission STS-93, when a hydrogen leak in the coolant tubes making up main engine No. 3's nozzle caused more oxygen to be consumed than expected. In that case, oxygen ECO sensors went "dry," triggering engine shutdown.
In both cases, the shutdowns happened late in the ascents and both shuttle crews were able to complete their missions.
05:00 a.m., 09/08/06, Update: Engineers troubleshoot possible engine cutoff sensor problem
Engineers fueling the shuttle Atlantis for launch today are troubleshooting a possible problem with a hydrogen engine cutoff - ECO - sensor in the ship's external tank. During a test, hydrogen ECO sensor No. 3 indicated it was wet when it should have indicated dry. The three-hour fueling procedure is continuing while engineers look into the issue and launch remains on track for 11:40:37 a.m.
NASA's Mission Management Team is assembling early to discuss the issue, according to NASA spokesman Bruce Buckingham. Because of problems during the first post-Columbia launch campaign, a launch rule modification is on the books that permits a flight to continue with three of four operational ECO sensors. But that rule, in its original form, also called for a 24-hour delay to fully assess the matter and as of this writing, it's not clear how today's countdown might proceed if the problem cannot be resolved.
Problems with hydrogen ECO sensors delayed the first post-Columbia mission last year. After the flight, engineers traced the problem to a suspect connection betweem sesors and electrical cables in a specific batch of ECO sensors manufactured in the late 1990s. The sensors in a tank used by the shuttle Discovery last month were replaced with a set thought to be fault free and those sensors worked as expected.
The hydrogen sensors in Atlantis' tank also were replaced.
The ECO sensors are part of a backup system that ensures the shuttle's main engines shut down normally before the tank runs out of fuel. NASA launch rules require all four ECO sensors to be operating before a launch can proceed.
But going into last month's flight, NASA managers developed rationale for an "exception" to the four-of-four flight rule that would permit a second launch attempt the next day if engineers could show the fault was in the shuttle's electronics system and not the sensors themselves.
Two of the four hydrogen ECO sensors would have to "fail dry" to trigger a premature engine shutdown. Three sensors would have to fail wet for the engines to run the tank dry. The three-of-four rationale was developed to cover a failed wet case. No such rationale was developed for the failed dry case.
Updates will be posted here as information becomes available.
02:55 a.m., 09/08/06, Update: Shuttle fueling underway
Engineers began pumping a half-million gallons of liquid oxygen and hydrogen rocket fuel into the shuttle Atlantis' external tank early today, setting the stage for blastoff on a thrice-delayed space station assembly mission.
The supercold propellants began flowing from huge dewars near launch pad 39B at 2:49 a.m., about an hour late because of work to replace a gaseous nitrogen purge control valve at the pad. There are no other problems of any significance and forecasters continue to predict a 70 percent chance of acceptable weather.
Liftoff is targeted for 11:40:37 a.m., roughly the moment Earth's rotation carries the launch pad into the plane of the international space station's orbit. If all goes well, commander Brent Jett will guide Atlantis to a docking with the space station just before 8 a.m. Sunday.
The goal of the 116th shuttle mission is to attach a $372 million solar array truss to the orbital lab complex, kicking off the resumption of station assembly after a three-and-a-half-year hiatus.
Here is a summary timeline of today's countdown highlights (all times in EDT):
07:30 p.m., 09/07/06, Update: Atlantis cleared for Friday launch try; NASA managers confident fuel cell up to task
NASA managers today cleared the shuttle Atlantis for launch Friday despite a suspect electrical generator, deciding the risk of an in-flight fuel cell shutdown that could prompt a shortened mission was not a credible threat to the thrice-delayed space station assembly flight.
If all goes well, engineers will begin loading a half-million gallons of rocket fuel into the shuttle's external tank around 1:45 a.m. Friday for a launch attempt at 11:40:37 a.m. The forecast calls for a 70 percent chance of good weather, but if problems prevent liftoff, NASA can make a final try Saturday at 11:14:55 a.m., the newly declared end of the window.
"After a very extensive review of the last almost 48 hours now, the team came to the conclusion today that the cloud that we saw over fuel cell No. 1 is probably acceptable to fly with," said shuttle Program Manager Wayne Hale. "We had another very fun and interesting Mission Management Team meeting.
"I've got to tell you that if you ever wanted to see the difference between the old NASA and the new NASA, you should have been over there today. There was a chance for everyone to participate, all the data was laid out on the table for everyone to examine, from the top of the agency down to the most junior engineer.
"We had a vigorous debate and we had many people give their opinions and arguments," Hale said. "And at the end of the day, when the Mission Management Team was polled by (Chairman) LeRoy Cain, it was not quite unanimous but very nearly unanimous with just a few folks voicing concerns that we go ahead and attempt to fly."
Some engineers, including representatives of UTC Power, the builder of the fuel pumps, believed it made more sense to replace the suspect fuel cell, which would have delayed the flight until after an upcoming Russian Soyuz flight to the space station.
But Hale ultimately sided with LeRoy Cain, who argued in favor of launching during Wednesday's MMT meeting, and ordered engineers to press ahead for a Friday launch.
Facing the Bush administration's 2010 deadline to complete the space station and retire the shuttle, and with multiple delays and just two flights under its belt since the 2003 Columbia disaster, some outside observers believe NASA managers are under pressure to resume station construction as soon as possible.
NASA Administrator Mike Griffin approved a shuttle launch in July over the objections of NASA's chief engineer and safety officer about external tank foam insulation that was officially classified as "probable/catastrophic" in NASA's risk matrix. At the time, Griffin said he disagreed with that assessment and said he decided to proceed because of the potential impact of a lengthy delay on the downstream station assembly schedule.
In the wake of the Columbia accident, NASA was criticized for putting the launch schedule ahead of flight safety and succumbing to "go fever." But Hale today dismissed concern that schedule pressure played into today's decision, saying "I think that's a cockeyed way to look at it."
Hale said the fuel cell problem never violated NASA's safety guidelines and that Atlantis could have been launched, by the book, without any additional debate.
"What I would tell you - no offense - what I would tell you is without having a requirement, without having what in the old days would have been considered any credible reason at all, we have stood down two days to make sure that we are safe to fly. OK?" Hale told CBS News. "So we have gone the extra mile. And I've gotta tell you, from where I sit, I don't feel like we're racing to the end of the window. OK?
"We have a couple of days available for launch and if we get the opportunity to go fly, I would like to take advantage of those couple of days. ... I feel very confident we're not racing, that we have, in fact, taken a very slow, methodical, thorough and safety-oriented approach in this whole matter, far and above what would have been done by folks in the old days."
The goal of the 116th shuttle mission is to install a 35,000-pound $372 million solar array on the end of a massive truss stretching across the U.S. Destiny laboratory module. It is the first of a half-dozen extremely complex flights to build out the solar arrays and prepare the station for arrival of European and Japanese research modules.
Engineers initially hoped to launch Atlantis Aug. 27, but the flight was grounded by a launch pad lightning strike and then by tropical storm Ernesto. A launch try Wednesday was called off after an apparent short circuit showed up in fuel cell No. 1.
Atlantis is equipped with three fuel cells that generate direct current electricity by combining oxygen and hydrogen in a sort of reverse electrolysis. That direct current is then converted into three-phase alternating current and distributed throughout the spacecraft across three electrical buses.
The short in question occurred in fuel cell No. 1's Freon coolant pump motor. While the motor runs fine on two-phase power, a subsequent short would knock it out of action and, without cooling, force the crew to shut down fuel cell 1. A fuel cell shutdown, in turn, would trigger a flight rule requiring the crew to shorten its mission and to land early.
If a minimum-duration flight was declared early, the astronauts would still be able to dock with the station, attach the new solar array and stage at least one spacewalk to plug it into the station's power and cooling systems. After that, the crew would be ordered home early. But Hale said he believed the odds of that, while not zero, were acceptably low.
Extensive testing over the past two days convinced most engineers the short is in the motor itself and poses little risk of additional trouble. Playing it safe, a circuit breaker will be pulled for the duration of the mission that will cut phase A power to the Freon pump motor, a hydrogen pump in fuel cell No. 1 and a temperature sensor.
Fuel cells do not lend themselves to repairs at the launch pad and in any case, NASA could not access the powerplants before the end of the launch window. The only realistic options were to fly as is or to order a swap out, a procedure that would take at least 11 days to complete at the launch pad.
Hale said the complexity of the repair job raised the threat of collateral damage and added that even if Atlantis was delayed past Saturday, he would not order a swap out.
In any case, the Russian space agency plans to launch a Soyuz rocket carrying the space station's next full-time crew on Sept. 18. Any launch past the 18th would result in a pre-dawn landing for the outgoing station crew Sept. 28, a scenario the Russians are adamant about avoiding.
In earlier discussions, NASA promised the Russians Atlantis would leave the station by Sept. 17 at the latest. NASA managers and their Russian counterparts have now agreed that Atlantis can remain docked to the station through Sept. 18 if necessary. That would permit the Atlantis astronauts to launch on Saturday, if required, and still extend the flight one day for additional heat shield inspections if required.
12:30 p.m., 09/07/06, Update: Updated countdown chart, flight plan, NASA TV sked posted for possible Sept. 8 launch
Engineers continue to assess the health of an electrical generator aboard the shuttle Atlantis today to develop a rationale for either pressing ahead toward launch Friday, the end of the current launch window, or standing down to replace the powerpack. NASA's Mission Management Team will meet at 2 p.m. to make a decision one way or the other.
At issue is whether a short inside fuel cell No. 1 that is preventing one of three phases of AC power from reaching the pump motor could worsen during the vibration of launch or later, shutting down the pump and forcing the crew to turn off the fuel cell to prevent over heating.
By pulling a circuit breaker, the crew can isolate the phase A circuit to prevent any short-related transients that might affect two of six main engine controllers during ascent.
Otherwise, the Freon pump can operate normally on two-phase power. But a subsequent problem could knock out the coolant pump, forcing shut down of fuel cell No. 1. That, in turn, would force the astronauts to carry out a so-called minimum-duration mission that could prevent them from accomplishing all of their space station assembly work.
During an MMT meeting Wednesday, the engineering community was split on whether to proceed with flight or replace the fuel cell. As of this writing, it's unclear whether data collected overnight will provide enough additional insight to permit a definitive resolution.
If NASA managers ultimately decide to swap out the pump - either before or after a Friday launch try - engineers believe the work could be accomplished at the pad in 11 days, setting up a launch attempt two weeks after the replacement work was ordered. That assumes NASA managers relax a launch constraint that currently requires takeoff in daylight for photo documentation of the shuttle's heat shield and external tank.
Even if the lighting constraint is eliminated, Atlantis would not be able to take off until after the Sept. 28 landing of a Russian Soyuz spacecraft carrying the international space station's outgoing crew back to Earth. Assuming a shuttle launch Sept. 30, for example, launch would be targeted for around 2:50 a.m.
If Atlantis fails to get off the ground Friday, and if the lighting constraint remains in force, launch would be delayed to Oct. 26. If engineers decide to forego good lighting for post tank separation in orbit, the launch window could open as early as Oct. 20.
Assuming NASA managers press ahead for a launch attempt Friday, here is an updated countdown chart for critical events (in EDT):
http://www.cbsnews.com/network/news/space/currentglance.html
08:30 p.m., 09/06/06, Update: Launch delayed to at least Friday pending resolution of fuel cell problem
NASA managers late today ruled out an attempt to launch the shuttle Atlantis Thursday but held open the possibility of a last-ditch Friday launching if engineers can resolve a problem with one of the ship's three electrical generators before time runs out.
The decision came at the end of a long day of troubleshooting, engineering analysis and discussion in which LeRoy Cain, chairman of NASA's Mission Management Team, recommended proceeding with a launch try Thursday. Shuttle Program Manager Wayne Hale and other senior agency officials disagreed and decided to err on the side of caution, ordering an additional 24-hour stand down.
The shuttle's launch window closes Friday and there is no time to make any actual repairs to fuel cell No. 1, one of three compact powerplants under the floor of the orbiter's forward cargo bay that supply the electricity needed to power Atlantis' myriad electrical systems.
If the engineering community can show the problem seen during launch preparations Tuesday and Wednesday won't get worse, NASA will proceed with an attempt to launch Atlantis Friday at 11:40:37 a.m. on a long-awaited space station assembly mission. Forecasters are predicting a 70 percent chance of good weather.
The only other option is to replace the suspect fuel cell, which would delay liftoff until Oct. 26 barring a decision to relax a self-imposed requirement for a daylight launch. That requirement was put in place to permit photo documentation of the shuttle's heat shield and external fuel tank insulation and if it is waived, Atlantis could fly shortly after a Russian Soyuz spacecraft brings the space station's outgoing crew back to Earth Sept. 29.
"If we get comfortable that this is safe and understood, then we'll go fly (Friday)," Hale said. "And if we don't get comfortable - take schedule out of this - if we don't get comfortable that it's safe to fly, we'll stand down and change the fuel cell out.
"This is one of those really 50-50 kind of decisions," he added. "If you want high drama, this is about as good as it gets."
NASA originally hoped to launch Atlantis Aug. 27, but the flight was delayed in the wake of a launch pad lightning strike Aug. 25 and then by tropical storm Ernesto. Thanks to an improved forecast and an unprecedented decision to reverse a move off the launch pad last week, Cain and Launch Director Mike Leinbach preserved three shots at launching Atlantis this week - Wednesday, Thursday or Friday - before the September launch window expires.
During fuel cell activation late Tuesday evening for a planned Wednesday launch try, engineers noticed an electrical "signature" indicating a short circuit somewhere in fuel cell No. 1 that prevented one of three phases of AC power from reaching a Freon cooling pump. Because of concern about the unusual signature, mission managers put launch on hold pending additional analysis.
The pump can run on normal two-phase power, but a subsequent failure would trigger a shut down and that, in turn, would force flight controllers to turn off the fuel cell to prevent over heating. Such a failure in orbit would trigger flight rules calling for a shortened, "minimum duration mission" and a quick return to Earth.
The goal of Atlantis' mission is to install a $372 million solar array truss segment, a complex task requiring three spacewalks and intricate work on the ground to orchestrate station powerdowns while the new equipment is wired into the lab's electrical and cooling system.
Going into the flight, NASA managers were preserving the option of extending the shuttle flight up to two days to permit additional heat shield inspections and to provide time to handle any unexpected assembly problems.
A launch Friday alreaady would eliminate any extension days because of a NASA promise to the Russians that the shuttle will undock from the station by Sept. 17 at the latest, clearing the way for the Sept. 18 launch of a Soyuz carrying the space station's next crew.
But a minimum duration flight, in a worst-case scenario, could force the crew to attach the new truss and then depart before completing all three planned spacewalks, causing a variety of downstream complications.
After extensive analysis, some engineers concluded Atlantis could be safely launched Thursday and that whatever was causing the short in the coolant pump motor had little chance of causing any additional problems. Others wanted more time to confirm that conclusion.
Cain, a former ascent/entry flight director serving as launch site chairman of the MMT for the first time, played a critical role keeping Atlantis on track for launch tries this week after the lightning strike and Ernesto.
At the end of today's discussion, Cain wanted to proceed with a launch try Thursday, but Hale and other senior agency officials disagreed.
"I'm a little disappointed to be here talking to you about this," Hale said late today. "I'd really hoped that I would be here doing a press conference at this hour telling you the results of launch. ... However, last night when we came in, or actually before most of the management team came in, when the fuel cells started up, there was an anomaly found in fuel cell No. 1.
"It's a very interesting thing. We do not have a violation of the launch commit criteria, we have not violated any of our requirements. But as we looked very carefully at this scenario that played out over a couple of hours with fuel cell 1, we decided there are some liens against that particular piece of equipment.
"The fuel cells generate the electricity for the shuttle, the shuttle requires electricity to fly and there are no batteries to speak of. So we're very interested in having good fuel cells. And again, the particular signature we saw was not a violation of our current launch rules but it did cause a great deal of engineering analysis to come back to say there is something funny going on in that fuel cell."
The shuttle's fuel cells, built by UTC Power, are located under the ship's cargo bay floor. They each weigh 255 pounds and measure 14 inches high, 15 inches wide and 40 inches long. They combine oxygen and hydrogen in a sort of reverse hydrolysis to produce electricity and, as a byproduct, water.
The fuel cells generate direct current that is routed through inverters to produce three-phase AC power. Normal household appliances run on two-phase AC power but the shuttle's systems use three-phase electricity to provide additional margin against failures.
Some of that AC power is routed back to the fuel cells to drive coolant pumps and other devices. Fuel cell No. 1 is generating the proper amount of electricity but somewhere in the system, one phase of the returning AC power is being prevented from reaching the Freon coolant pump motor.
Engineers need to make sure the vibration of launch won't cause additional electrical problems that, in some scenarios, could knock out one or more main engine computers. And they need to understand the consequences of a failure in orbit that could force flight controllers to shut down fuel cell No. 1, triggering a minimum duration mission.
"The bottom line coming out of today's meeting is we decided it would be prudent for us to spend another 24 hours looking more closely at the engineering analysis to understand what we've got," Hale said. "I still am hopeful, and I certainly believe there's an opportunity to launch Friday morning."
But, he added, "I would like to have a high degree of confidence that we are not at significant risk of incurring a minimum duration flight before we go launch. That's one of the things I'm going to be looking for the engineering team to come back and say we really think we have a good handle on this problem and it won't propagate to the next level and cost me several days off the flight."
He stressed that in their current condition, the fuel cells are fully operational and "we have no violation of our launch commit criteria. The fuel cell works fine on two phases and it has been working fine since we turned it on and there is certainly the probability it will continue to work fine for the full duration of the mission."
"What we have here, however, is a signature which is a new engineering indication that casts some doubt on the health of that fuel cell and whether it would be able to support the full 12 to 14 days we want to fly this flight," he said.
Asked why this option was more attractive than simply changing out the fuel cell, waiving the daylight launch requirement and flying at the end of the month, Hale said other than the fuel cell issue, Atlantis is ready to fly.
"What it is, we're all suited up. The crew's here, all the teams are here, the shuttle's out on the pad, everything's ready to go and from a program management standpoint, you always say is there a reasonable way we can decide it's safe to fly?
"If we cannot prove it's safe to fly, we won't fly," he said. "That's the principle and I stand beside it. The real puzzler to this is the condition we are in is not an unsafe condition. Our engineering requirements documents say as we are, it's good to go fly. What we have taken here is an extra look at safety. We've gone above and beyond what our safety requirements are (but) we think it is prudent that we understand (the issue) fully before we go commit to fly."
02:20 p.m., 09/06/06, Update: NASA managers mull fuel cell options
NASA's Mission Management Team met today to discuss options for launching the shuttle Atlantis on a key space station assembly mission. A launch try today was scrubbed because of a possible short in one of the shuttle's three electricity producing fuel cells. It does not appear engineers have time to carry out any repairs before the current launch window runs out Friday, but they could opt to fly as is if troubleshooters can show the glitch can be isolated and not cause additional problems.
But that could be a tough sell. Depending on the exact cause of the 1.5-amp current increase and an associated voltage spike that showed up in fuel cell No. 1's coolant pump motor, additional failures could lead to trouble with main engine computers and other critical systems during the climb to space.
If troubleshooters determine Atlantis can't safely fly in its current condition, engineers could replace the fuel cell at the launch pad, a complex job that could take up to a week or so to complete.
In 1995, the shuttle Endeavour was hauled off its launch pad because of an approaching hurricane, then moved back in place for a launch try Aug. 31, 1995. That attempt was called off prior to fuel loading because of problems with fuel cell No. 2. The powerplant was changed out at the pad and Endeavour rocketed into orbit Sept. 7, 1995 - 11 years ago Thursday.
NASA originally hoped to launch Atlantis Aug. 27, but the flight was delayed by a launch pad lightning strike Aug. 25 and then by the approach of tropical storm Ernesto. Atlantis was briefly moved off its launch pad last week before the trip was called off thanks to an improving forecast.
But like Endeavour 11 years ago, engineers ran into fuel cell problems late Tuesday, before the planned start of fuel loading early today.
NASA faces a very limited set of launch options because of the upcoming Sept. 18 launch of a Russian Soyuz spacecraft carrying the space station's next crew and a self-imposed requirement to launch Atlantis in daylight for photo documentation of the shuttle's heat shield and external tank insulation. The next lighted launch window opens Oct. 26 and lasts just two days.
NASA managers began reviewing the rationale for the daylight launch requirement in the wake of recent weather delays and the need to get on with station assembly. No final decisions have been made, but if the daylight launch requirement ultimately is relaxed, Atlantis could be ready for another launch try within days of the Sept. 29 landing of a Russian Soyuz carrying the outgoing space station crew.
In the near term, NASA managers could opt to press ahead for a possible launch try Thursday while troubleshooting continues, deferring a final decision until later this evening, but again, no decisions have been made. This status report will be updated following a post-MMT news conference later today.
07:15 a.m., 09/06/06, Update: Updating countdown, flight plan, ascent data, etc., to reflect possible Sept. 7 launch
The STS-115 flight plan, launch day countdown and ascent timeline have been updated to reflect a possible Sept. 7 launch of the shuttle Atlantis if engineers can resolve concerns about the health of fuel cell No. 1.
Text versions of the launch-day countdown and flight plan, which includes the latest rendezvous, docking, undocking, deorbit and landing times, are available on the CBS News STS-115 Quick-Look page:
http://www.cbsnews.com/network/news/space/currentglance.html
SpaceCalc screenshots also are available in the sidebar to the right. Additional updates will be posted as warranted.
04:30 a.m., 09/06/06, Update: Troubleshooting plan; MMT meeting on tap (05:10 a.m. update: adding fuel cell background)
NASA managers stopped the shuttle Atlantis' countdown early today and put launch on hold for at least 24 hours because of problems with one of the ship's three electricity producing fuel cells.
Engineers are continuing to troubleshoot the issue in hopes of getting Atlantis off the ground Thursday or Friday, the end of the current launch window. NASA's Mission Management Team plans to meet later today to discuss repair options.
It may be possible to press ahead with launch Thursday or Friday if the engineering community can get comfortable with the apparent internal short that was observed when fuel cell No. 1 was powered up earlier today.
But if not, and if the powerplant cannot be repaired at the launch pad, NASA could be forced to haul Atlantis back to its hangar for a fuel cell swap out, a move that would delay launch several weeks. As of this writing, however, no such decisions have been made.
NASA originally hoped to launch Atlantis on a space station assembly mission Aug. 27, but the flight was delayed by a launch pad lightning strike Aug. 25 and later, by tropical storm Ernesto.
With forecasters predicting a 70 percent chance of good weather today, engineers were gearing up to load a half-million gallons of liquid oxygen and liquid hydrogen rocket fuel into Atlantis' external tank for a launch attempt at 12:29 p.m.
But before fueling began, engineers noticed the problem with fuel cell No. 1's phase A bus, one of three power units in the device. Fuel loading was delayed pending resolution of the fuel cell problem, but engineers ran out of time and the launch was scrubbed a few minutes before 4 a.m.
The shuttle's fuel cells, built by UTC Power, are located under the ship's cargo bay floor. They each weigh 255 pounds and measure 14 inches high, 15 inches wide and 40 inches long. They combine oxygen and hydrogen in a sort of reverse hydrolysis to produce electricity and, as a byproduct, water. All three must be operating normally for a countdown to proceed.
"The three fuel cells operate as independent electrical power sources, each supplying its own isolated, simultaneously operating 28-volt dc bus," according to NASA's space shuttle reference manual. "The fuel cell consists of a power section, where the chemical reaction occurs, and an accessory section that controls and monitors the power section's performance.
"The power section, where hydrogen and oxygen are transformed into electrical power, water and heat, consists of 96 cells contained in three substacks. Manifolds run the length of these substacks and distribute hydrogen, oxygen and coolant to the cells. The cells contain electrolyte consisting of potassium hydroxide and water, an oxygen electrode (cathode) and a hydrogen electrode (anode).
"The accessory section monitors the reactant flow, removes waste heat and water from the chemical reaction and controls the temperature of the stack. The accessory section consists of the hydrogen and oxygen flow system, the coolant loop and the electrical control unit."
Today's problem might have been caused by internal debris that triggered a short in one of the substacks, sources said. If so, it's not yet clear how the vibration of launch might affect the fuel cell or whether additional problems could be expected.
Fuel cells do no lend themselves to on-pad repairs and if the problem in fuel cell No. 1 cannot be easily resolved, engineers could be forced to remove the shuttle's payload and roll Atlantis back to its hangar so the powerplant can be replaced. That scenario likely would delay launch for several weeks.
The goal of the 116th shuttle mission is to deliver and install a $372 million solar array truss, restarting space station assembly after a three-and-a-half-year hiatus in the wake of the 2003 Columbia disaster.
Atlantis' flight and the next half dozen in the assembly sequence are considered among the most complex manned space missions ever attempted. Because each flight builds on the work accomplished during the previous mission, they must be conducted in sequence and any major delay could cause problems for downstream missions.
NASA is operating under a self-imposed requirement to launch Atlantis in daylight for photo documentation of the shuttle's heat shield and external tank insulation. The next lighted launch window opens Oct. 26 and lasts just two days. NASA managers already were in the process of reviewing the rationale for that requirement, which greatly restricts launch opportunities this time of year.
The Sept. 8 end of the current launch window was defined by conflict with Russian plans to launch a fresh crew to the space station aboard a Soyuz spacecraft Sept. 18 and to return the lab's outgoing crew Sept. 29.
If Atlantis isn't off the ground by Friday - and if NASA ultimately relaxes the daylight launch constraint - the shuttle could fly as early as Sept. 30 if the fuel cell problem can be resolved at the launch pad.
If the flight slips to late October, a planned December flight by shuttle Discovery could be pushed into January and three critical spacewalks by the station's crew could be delayed in turn.
This status report will be updated as new information becomes available.
03:55 a.m., 09/06/06, Update: Launch called off
NASA managers stopped the shuttle Atlantis' countdown early today and put launch on hold because of problems with one of the ship's three electricity producing fuel cells.
Engineers are continuing to troubleshoot the issue in hopes of getting Atlantis off the ground Thursday or Friday, the end of the current launch window. But if the powerplant has to be replaced, NASA could be forced to haul Atlantis back to its hangar for repairs, a move that would delay launch several weeks.
Engineers at the Kennedy Space Center are troubleshooting a problem with fuel cell No. 1 aboard the shuttle Atlantis. The loading of rocket fuel is on hold and if the problem is not resolved by 4 a.m. or so, today's launch attempt likely will be scrubbed, officials said.
The shuttle is equipped with three electricity producing fuel cells that combine oxygen and hydrogen to produce electricity. All three must be operating normally for a countdown to proceed.
During powerup early today, a problem showed up in fuel cell No. 1's phase A power bus, one of three power sources within the device. Engineers may shut down and restart the powerplant in a bid to clear the problem or at least understand the unexpected "signature."
Launch remains targeted for 12:29 p.m., assuming the fuel cell problem can be resolved by 4 a.m. or so. Updates will be posted here as new information becomes available.
12:00 p.m., 09/05/06, Update: Weather now 70 percent 'go;' Hale discusses ice-frost ramp redesign, mission extension options
NASA managers are holding open the possibility of extending the shuttle Atlantis' mission by at least one and possibly two days to give the crew time to carry out additional heat shield inspections and to handle any unexpected problems that might crop up, officials said today.
Atlantis is scheduled for blastoff Wednesday at 12:29 p.m. on a space station assembly mission considered one of the most complex shuttle flights in recent memory. There are no technical problems of any significance at pad 39B and forecasters are predicting a 70 percent chance of good weather Wednesday, Thursday and Friday.
"We really are working no issues, the vehicle's in very good shape," said LeRoy Cain, launch site chairman of NASA's Mission Management Team. "I conducted the go/no-go poll to continue and everybody on the team is go and in good spirits. We're ready to press forward from here."
Launch Director Mike Leinbach said engineers may move the launch pad service gantry away from Atlantis an hour or so early today to beat the onset of expected afternoon thunderstorms.
"If we get it back before the weather sets in, that's great," he said. "If not, we'll recover that time after the weather passes. Typically, we hold four or five hours in abeyance for RSS (rotating service structure) retract. So if we do get hit by the afternoon weather, that really shouldn't pose a problem for us."
The Mission Management Team plans to meet at 1:45 a.m. Wednesday to assess the weather and give engineers clearance to proceed with loading Atlantis' external tank with liquid oxygen and hydrogen rocket fuel.
Fueling is scheduled to begin at 2:33 a.m. and if all goes well, commander Brent Jett, pilot Chris Ferguson, flight engineer Dan Burbank, Joe Tanner, Canadian astronaut Steve MacLean and Heidemarie Stefanyshyn-Piper will begin strapping in around 9:09 a.m.
Liftoff is targeted for 12:28:49 p.m. If Atlantis fails to get off the ground Wednesday, NASA can try again Thursday and Friday. After that, the flight will be delayed until after the Russians launch a fresh crew to the international space station Sept. 18 and bring the lab's outgoing crew back to Earth Sept. 29. The next daylight launch opportunity or the shuttle after Friday is Oct. 26.
With an on-time launching, Atlantis will dock with the space station Friday at 8:40 a.m. The next day, a new solar array truss will be attached to the outpost and the crew will stage the first of three spacewalks to make critical electrical connections, remove launch restraints and perform other activation tasks.
As it now stands, a second spacewalk would be carried out the next day, followed by solar array extension the day after that and then a third spacewalk. But managers may insert an extra day between the first two spacewalks to let the crew carry out "focused inspections" of the shuttle's heat shield based on whatever they see during an initial inspection the day after launch.
"We don't (currently) have that scheduled in the STS-115 timeline, but we know that is a likely possibility based on the flight day two or three inspections, that we'll need to go back and look at some areas in more focused detail," said shuttle Program Manager Wayne Hale. "There's a hope that perhaps we won't need to do that.
"The more difficult case for the team to execute, both the astronauts in orbit and mission control, is two back-to-back EVAs. If we need to do a focused inspection, the thinking is ... we would insert a day between the first and second EVAs. That becomes a somewhat lighter day for the crew and mission control, so it's an easier day to stand by for.
"What we'd really like to do is not have to do focused inspection, in other words, have such a clean vehicle that no inspections are required. Then we can save that day, bank it, and keep it (for) the end of the mission in case we run into any difficulties in the assembly process. Lifting off tomorrow or even the day after tomorrow, we really will have the capability to extend not one, but two days to the docked period so we would have the capability to handle both contingencies."
If an extension day is, in fact, inserted after the first spacewalk, the second spacewalk would occur on Sept. 11, the fifth anniversary of the terrorist attacks on New York City and Washington.
In other developments, Hale gave reporters an update on NASA's work to develop safer ice-frost ramps on the shuttle's external tank. The ice-frost ramps are buildups of foam insulation around brackets that support two pressurization lines and a cable tray. The insulation prevents ice from forming that could break off during launch and strike the shuttle.
The IFRs are manually sprayed on and then sculpted on top of so-called acreage foam. Post-Columbia testing shows areas where foam is applied on top of other foam are susceptible to cracking due to differential thermal effects. Cracks, in turn, can lead to foam shedding during launch.
The IFRs are officially classified as "probable/catastrophic," meaning there is a 50-50 chance of a catastrophic failure over the 100-flight life of a space shuttle. It is the only system on the shuttle that is so classified and NASA is developing a near-term fix to reduce the chances of foam debris breaking away.
"One of the options was to cover these little pieces of foam, about a pound or two pounds of foam at every bracket, cover them with a titanium shell, titanium being a metal that would retain the foam," Hale said today. "Titanium has a low thermal conductivity, so the hope was they could fasten that to this tank and not have ice form on the outside.
"They were unsuccessful in the environmental testing and the thermal testing to prevent ice from forming on the outside of the metal brackets. So the option (under development) is to reshape the foam, a reformulation of the foam to remove the SLA, or super-lightweight ablative foam core, and just use the standard foam."
The all-foam design "will be what we take to the wind tunnel tests later this month to make sure it will hold together," Hale said. The new design is similar in appearance to an earlier design that broke apart during wind tunnel testing last spring. It was that failure that prompted NASA to stick with the current design, accepting the associated risk, while engineers developed an improved design.
"To the casual observer, it's not going to look a whole lot different than what we tried last April that didn't hold together in the wind tunnel," Hale said. "There are some differences internally in the way it's put together and some small shape differences. The bottom line is, we want to reduce the footprint.
"Every one of these 17 ice-frost ramps on the hydrogen part of the tank has a footprint of foam over foam, which is what we believe causes us concern with shedding of foam. So we have reduced the area of foam on top of foam, it's a much smaller footprint, and the thermal analysis indicates we will be much less susceptible to the thermally induced cracking that occurs in the underlying foam region, which is the goal of this exercise.
"This is an interim fix," Hale said. "We're coming back with a final fix in about eight more tanks after that. So we think we've got a good design, we'll put it in the wind tunnel later this month to make sure we've got a good design. We're going to have the critical design review before we start modifying the tank that's in production at the Michoud Assembly Facility, which we hope to ship about mid December."
That tank, Hale said, will be used with shuttle mission STS-117 next February.
06:30 p.m., 09/04/06, Update: NASA set for three consecutive launch attempts if necessary; lighting rationale review continues
NASA managers today agreed to make three consecutive attempts to get the shuttle Atlantis off the ground if bad weather or technical problems prevent an on-time liftoff Wednesday.
The forecast calls for an 80 percent chance of good weather Wednesday, decreasing to 70 percent "go" Thursday and Friday. If Atlantis isn't off the ground by Friday, the flight will be delayed to late October, barring a decision to relax NASA's current daylight launch requirement.
The space agency normally gives the launch team a day off after two straight attempts but given the high stakes involved, and the impact of a major delay on NASA's plans to resume station assembly, the launch team agreed to make three attempts in a row if necessary.
Liftoff Wednesday is targeted for 12:29 p.m., a week and a half behind schedule because of a launch pad lightning strike and delays caused by tropical storm/depression Ernesto.
"We certainly had our share of tropical weather, or at least the potential for tropical weather the last week or two, which put us a little behind in the schedule," said shuttle program manager Wayne Hale. "However, in the bigger scheme of things, a week or so waiting out the weather will not cause us any concern.
"We have a good shot at three consecutive launch dates coming up the middle of this week. We owe this to the really hard work from the launch team that spent not just today, the Labor Day holiday out here working, but the whole weekend and in fact every day since Ernesto passed as well. So we are looking forward to a really good mission."
Launch director Mike Leinbach said NASA has only attempted three launches in a row once before. The normal practice is to make two attempts and then to stand down a day to give the launch team a break before making two more attempts.
"If you give us four attempts in five days, (our success rate is) something on the order of 90 to 95 percent," he said. "So three in a row is probably in the low 90s.
"The team is really excited to try to do this," he said. "This is what we're in the business for. To a man, to a woman, there were no disagreements at all about trying three in a row. We want to get this vehicle in orbit. I feel we have a pretty good shot at it, I really do. It's got to be in the 90-percentile range."
While hoping for the best, NASA managers are continuing a review of the current daylight launch requirement, which permits photo documentation of the shuttle's heat shield and external tank insulation. Hale said if Atlantis doesn't get off this week, that review will play into discussions about when the shuttle could be readied for another attempt.
The current launch window closes Friday because of conflict with launch of the space station's next full-time crew aboard a Russian spacecraft - Soyuz TMA-9 - and the Sept. 29 landing of the lab's outgoing crew aboard the Soyuz TMA-8 capsule. Based on lighting alone, the next shuttle launch window would open Oct. 26. Without that requirement, Atlantis could launch within days of the Soyuz TMA-8 landing.
The goal of the 116th shuttle mission is to deliver and install a $372 million solar array truss, kicking off the resumption of space station assembly after a three-and-a-half-year hiatus.
Atlantis' flight and the half dozen that follow will nearly complete the station's main solar array truss, which will stretch the length of a football field, and ready the outpost for attachment of European and Japanese research modules.
"Clearly, we are into the heart of the assembly sequence of the international space station," Hale said. "As we bring up the solar arrays, we are configuring the power system from its early assembly interim configuration to the final configuration and there is a huge rewiring on the station (required), both from the electrical power system, the generation and distribution of electrical power, as well as the cooling situation. Because all of that power, as it gets used, turns into heat and must be removed and the entire cooling system is being re-plumbed in the course of the next three or four shuttle assembly flights.
"And then following that, we bring up major modules, the international partners' modules that will be doing the bulk of the research, at least from their point of view, in addition to the U.S. lab that is just crucial to the success of the international space station. This is clearly a very complicated task. When you try to compare it to moonwalks or other things we have done in the past, then it's very difficult to compare. In terms of EVA tasks, spacewalk tasks, clearly these are the most complicated spacewalk and assembly tasks that have ever been done before."
Hale said he was excited to be this close to launch "because this is the purpose for which we fly."
"We're not flying the shuttle just as some kind of engineering experiment, although some folks would be happy to do that," he said. "We're flying the shuttle for a purpose, to carry a payload, to create this marvelous research outpost.
"It is really the purpose we are here for and I'm excited that after a substantial period of time of redesign and rethinking and retooling and preparation we are into the heart of the assembly. And we have certainly got our fingers crossed that it's going to go very well and we have made plans to cover every possible contingency we can think of."
11:15 a.m., 09/04/06, Update: Countdown on track; weather 80 percent 'go'
Engineers loaded the shuttle Atlantis' fuel cell system with liquid hydrogen and oxygen early today, a key step in readying the spacecraft for launch Wednesday on a weather-delayed space station assembly mission. There are no technical problems of any significance at launch complex 39B, officials said today, and forecasters are continuing to predict an 80 percent chance of good weather.
"Everything is tracking extremely well, we're tracking no issues at this time," said NASA Test Director Jeff Spaulding. "We'll continue through our engine checkouts later on tonight and then we'll work towards power up of our ground communications network and do that checkout at nine thirty Tuesday morning. Rotation of our rotating service structure is planned for three o'clock tomorrow afternoon. We will, of course, be watching the weather on that."
Afternoon thunderstorms could hold up rotation of the massive launch pad gantry, but no major problems are expected. Assuming the countdown stays on track, engineers will begin loading Atlantis' huge external tank with liquid oxygen and hydrogen rocket fuel around 2:30 a.m. Wednesday for a launch attempt at 12:28:49 p.m.
"Atlantis and her crew have been waiting for years to complete this mission and thanks to Ernesto, they've had to wait about a week longer," Spaulding said, referring to the storm that prevented an Aug. 27 launch attempt. "So I'm pleased to announce that wait's nearly over and that we'll be ready on Wednesday for Atlantis' launch."
Because of conflict with the launch of a Russian Soyuz spacecraft carrying the space station's next full-time crew, Atlantis must be off the ground by Friday at the latest or the flight will be delayed until late October, barring a decision by NASA to relax a daylight launch requirement.
The forecast for Thursday and Friday is 70 percent "go." While NASA doesn't normally make three launch attempts in a row, agency managers could waive that guideline if weather or other problems keep Atlantis on the ground past Thursday.
LeRoy Cain, chairman of NASA's Mission Management Team, and Launch Director Mike Leinbach will brief reporters later today on the status of launch preparations.
09:15 a.m., 09/03/06, Update: Countdown begins; weather 80 percent 'go'
With little fanfare, NASA restarted the shuttle Atlantis' countdown today for blastoff Wednesday on a long-awaited mission to restart space station assembly.
The countdown began at 8 a.m. for a launch try Wednesday at 12:29 p.m., a week and a half behind schedule because of a launch pad lightning strike Aug. 25, which prevented an Aug. 27 launch, and then tropical storm/hurricane Ernesto.
As with Atlantis' first launch try, the 76-hour 23-minute countdown began six hours earlier than normal. That will give engineers a better chance of getting the shuttle's fuel cell system loaded with liquid oxygen and hydrogen Monday morning before any afternoon storms can develop and provide additional time to handle unexpected problems.
The latest Air Force weather forecast calls for an 80 percent chance of acceptable weather Wednesday, dropping to 70 percent "go" Thursday and Friday.
"Our primary concerns for launch are cumulus clouds within 10 nautical miles of (launch) complex 39B and isolated showers within 20 nautical miles of the Shuttle Landing Facility," according to the forecast.
"The probability of KSC weather prohibiting launch increases slightly the following two days due to a frontal boundary approaching Central Florida from the northwest. This boundary with strong upper level winds from the west may cause anvil clouds from thunderstorms in the Gulf of Mexico and along the west coast of Florida to (move) east toward KSC."
NASA safety rules forbid a launch if electrically active anvil clouds move within a few miles of the launch site.
Here is a timeline of countdown highlights (in EDT). A more detailed countdown chart is posted on the CBS News STS-115 Quick-Look page:
10:45 a.m., 09/02/06, Update: Astronauts fly back to Kennedy; countdown begins Sunday
The Atlantis astronauts flew back to the Kennedy Space Center today for launch Wednesday on a weather-delayed space station assembly mission. The countdown begins at 8 a.m. Sunday with launch on tap, weather permitting, at 12:29 p.m. Wednesday.
Arriving in T-38 jet trainers, commander Brent Jett, pilot Chris Ferguson, flight engineer Dan Burbank, Joe Tanner, Steve MacLean and Heide Stefanyshyn-Piper landed at the spaceport's 3-mile-long shuttle runway around 9:30 a.m., two hours ahead of schedule.
The astronauts originally hoped to take off Aug. 27, but the flight was delayed, first by testing after a powerful launch pad lightning strike Aug. 25 and then by concern about tropical storm/hurricane Ernesto.
The storm's projected track and strength prompted NASA managers to order Atlantis moved off its seaside launch pad and back to the protection of the Vehicle Assembly Building early Aug. 29.
But before the shuttle could reach the VAB, LeRoy Cain, chairman of NASA's Mission Management Team, and launch director Mike Leinbach changed their minds and ordered the shuttle back to the pad after an updated forecast that lowered predicted wind speeds.
As it turned out, Ernesto weakened even more by the time is reached Florida's space coast and the unprecedented decision to return Atlantis to the pad preserved a chance to get the mission off the ground before the end of its September launch window.
"Last Tuesday, as the center here was preparing for tropical storm Ernesto, we were flying back to Houston," Jett said today at the landing strip. "In fact, we made a left turn out over the pad and as we did, we saw Atlantis on the crawler headed for the VAB. I think all of us thought we were going to be spending a little while in Houston, but I think we're all really happy, just four days later, we're back here, we've got a shot at this launch window.
"The past week and a half, we've been fortunate enough to observe the team here at KSC work a lot of issues, from the lightning strike to the threat of Ernesto, and then getting Atlantis back ready (to fly). These guys never cease to amaze me, they've done a terrific job, from the crawler crews all the way to the leadership of Mike and LeRoy. They're dedicated, they work hard and they're good at what they do.
"We're honored to be here to work with them this week," Jett said. "There's a saying that if you work hard, you bring yourself good luck. If that's true, these guys deserve some good luck this week with the weather. I hope they get to see Atlantis leave the pad on Wednesday."
NASA has not yet released an official forecast for Wednesday, but the National Weather Service is predicting a 40 percent chance of rain with partly cloudy skies and scattered showers and thunderstorms.
The launch window, based on the space station's orbit and NASA's desire to launch Atlantis in daylight for photo documentation of the ship's heat shield and external tank, originally extended through Sept. 7. The close of the window was due to a conflict with a Russian mission to launch the space station's next crew and to return the outgoing crew to Earth.
In the wake of Ernesto, NASA was able to extend the window one day to Sept. 8 after agreeing to give up one potential in-flight extension day and guaranteeing the Russians Atlantis will undock from the station Sept. 17 at the latest.
That will clear the way for launch of the Expedition 14 crew aboard the Soyuz TMA-9 spacecraft on Sept. 18 and, more important, the return of the outgoing Expedition 13 crew at dawn on Sept. 29. A shuttle launch past Sept. 8 would have forced the Russians to delay the Soyuz launch, resulting in a nighttime landing for the returning station crew aboard the Soyuz TMA-8 capsule. The Russians don't want to do that for safety reasons.
The goal of Atlantis' mission is to deliver a $372 million solar array segment to the space station and restart assembly after a three-and-a-half-year hiatus. When the astronauts arrived at the Cape for their first launch attempt, Canadian astronaut MacLean promised reporters a gold medal performance in space.
"I hope we still get a good gold medal," he said today. "But I also promised a very good story. The story starts with the lightning bolt that hit the shuttle, followed by Ernesto that teased us into a dancing shuttle two-step. For me, the mission will be complete when the solar panels are deployed. The borders of the solar panels are all golden, so there's a little bit of gold there as well!
"I really encourage everyone to watch the middle of the mission, to see how we do, and I expect that you'll be on the edge of your seats. With the ground team, I think we'll give you a good show with a good story to tell everybody else."
If Atlantis isn't off the ground by Sept. 8, the flight will be delayed to late October, barring a NASA decision to give up the current daylight launch requirement. The next daylight window opens Oct. 26 and closes Oct. 27. If NASA gives up a requirement for external tank lighting in orbit, the opening of the window could be moved up to Oct. 20.
NASA managers are reviewing the rationale for the daylight launch requirement and if that rationale is relaxed, Atlantis could take off within a day or so of the Soyuz TMA-8 landing.
But no decisions have been made and in any case, it will be a moot point if Atlantis gets off the pad next week and if its external tank performs well. Assuming no new tank problems, NASA already intended to resume night launchings with the next shuttle flight in December.
An updated countdown chart is now posted in text format on the CBS News STS-115 Quick-Look page and as a gif graphic on this page. Revision D of the NASA television schedule is posted on the Quick-Look page, along with an updated trajectory timeline for launch attempts Sept. 6 and 7.
NASA does not plan any media events Sunday, but will hold a countdown status briefing Monday at 10 a.m. and a pre-launch news conference around 4 p.m., after the L-minus two-day Mission Management Team review.
06:30 p.m., 08/31/06, Update: NASA sets Sept. 6 as target launch date
NASA managers today set Sept. 6 as the new target launch date for shuttle Atlantis after a launch pad inspection revealed no wind damage from the passage of tropical depression Ernesto Wednesday night. Liftoff is set for 12:28:49 p.m. Wednesday, weather permitting.
Atlantis commander Brent Jett, pilot Chris Ferguson, flight engineer Dan Burbank, Joe Tanner, Steve MacLean and Heide Stefanyshyn-Piper plan to fly back to the Kennedy Space Center from Houston early Saturday. The countdown is scheduled to begin Sunday.
As it now stands, NASA will have three days to get Atlantis off the ground: Sept. 6, 7 and 8. If not, the flight will be delayed to late October or, if NASA relaxes a daylight launch requirement, at some point after the Sept. 29 landing of a Russian Soyuz spacecraft carrying the international space station's outgoing crew.
12:20 p.m., 08/30/06, Update: NASA, Russians agree to extend shuttle launch window through Sept. 8 UPDATED at 5:30 to include Russian decision to forego possible Sept. 14 Soyuz launch
NASA and Russian space managers agreed today to extend the shuttle Atlantis' launch window by one day, to Sept. 8, to bolster the U.S. space agency's chances of getting the weather-delayed shuttle off the ground this month.
To get the extra day, NASA managers agreed Atlantis will undock from the international space station by Sept. 17 at the latest, clearing the way for launch of a Russian Soyuz rocket carrying the space station's next crew at 12:08 a.m. EDT on Sept. 18.
NASA managers hope to have Atlantis ready for launch by Sept. 6, if possible, after tropical storm Ernesto passes through the Kennedy Space Center area.
A launch on Sept. 6 or 7 would permit NASA to extend the docked phase of the mission by up to two days to give the crew time for additional heat shield inspections, if necessary, or to deal with other contingencies. A launch on Sept. 8, however, would force NASA to forego one additional docked day in order to ensure an undocking on Sept. 17.
Any shuttle launch past Sept. 8 would force the Russians to delay the launch of Soyuz TMA-9. And that, in turn, would delay the return of the station's outgoing crew aboard the Soyuz TMA-8 spacecraft, resulting in a night landing. For safety reasons, the Russians want to avoid that scenario if at all possible.
Under current planning, if Atlantis fails to get off the ground by Sept. 8 the flight will be delayed to around Oct. 26, barring a NASA decision to relax current rules requiring a daylight launch. In that case, the Russians had hoped to move the Soyuz TMA-9 launch back up to Sept. 14, the mission's original launch date before the Russians agreed to accommodate launch attempts through Sept. 7. Now that Sept. 8 is a possibility for Atlantis, the Russians have decided to forego any attempt to launch the Soyuz on Sept. 14 and to focus exclusively on Sept. 18.
Shuttle flight plans for Sept. 6-8 are posted in the SpaceCalc screenshot directory in the sidebar to the right. All other timelines and charts have been updated to reflect a possible Sept. 6 launch. Engineers will not know if that date is feasible until after detailed post-Ernesto inspections Thursday and Friday.
The CBS News STS-115 Quick-Look page now includes updated launch windows, a countdown chart and the flight plan for a possible launch on Sept. 6:
http://www.cbsnews.com/network/news/space/currentglance.html
06:20 p.m., 08/29/06, Update: Leinbach says launch try possible by Sept. 6; flight plan overview
If shuttle Atlantis weathers tropical storm Ernesto without any major problems, and if engineers can complete hurried preparations, NASA may be ready to make a launch attempt as early as Sept. 6, one day before the shuttle's launch window closes, officials said late today.
Launch Director Mike Leinbach said earlier that if the shuttle was moved from its launch pad, it would take eight days to ready the ship for takeoff from the point it was returned to the firing stand.
"If we were in the VAB (vehicle Assembly Building) and had to roll out to the pad to get to our first launch attempt, that was eight days," he said. "We'll already be at the launch pad, that saves a half day right there. We'll also kick off as much of the launch pad connections as we can get done tonight, that saves more time.
"Any kind of launch dates are predicated on how long we'll be cleared from the space center (because of Ernesto)," he added. "We're assuming it'll only be tomorrow afternoon and tomorrow evening and we should be able to get back into the space center Thursday. If that's the case, the plan rolls out to an attempt September the sixth or September the seventh. We're finalizing that now, we do not have a firm date. But it's in the sixth/seventh kind of time frame."
Leinbach and other senior managers decided early today to move Atlantis off the launch pad and back to the VAB because of concern about high winds from Ernesto. At the time, forecasters were predicting sustained winds of 50 knots as the storm passed by the Kennedy Space Center with gusts to 65 knots.
NASA's launch pad safety limit is 70 knots and shuttle managers, deciding it was too close to call, erred on the side of caution and ordered engineers to start moving Atlantis off the pad. The 4.2-mile trip began at 10:04 a.m. and was expected to take about 10 hours to complete.
But later in the day, the forecast changed. While south Florida was expected to get hit by 55-knot winds and gusts up to near hurricane strength, the space center was expected to see 45-knot winds with gusts to 55 Wednesday night, well below the launch pad's 70-knot limit.
After discussing the weather with forecasters and other senior managers, Leinbach and LeRoy Cain, chairman of NASA's Mission Management Team, ordered an unprecedented rollback reversal. At 2:45 p.m., NASA's ponderous crawler-transporter began creeping back toward the pad. If all goes well, Atlantis and its mobile launch platform will be "hard down" at the pad shortly after 8 p.m. A massive rotating service structure will be moved into place around the shuttle shortly thereafter and wind screens will be extended.
The wind screens and the RSS virtually surround the space shuttle at the pad, protecting the orbiter from wind-borne debris and rain. A lightning protection system shields the orbiter from electrical activity. The external fuel tank, at least the side away from the shuttle, is pretty much exposed to the elements.
"We followed the data, we met our criteria and I feel very good about the decision," Leinbach said. "There's no trepidation in my mind at all about the decision. This is the right way to go. It was a good exercise in time, we protected both options."
It remains to be seen whether NASA can, in fact, ready Atlantis for a launch attempt as early as Sept. 6. If so, a standard three-day countdown would begin this Sunday afternoon and engineers would begin pumping hydrogen and oxygen rocket fuel into the shuttle's external tank around 2:30 a.m. next Wednesday for a launch attempt at 12:29 p.m.
"The plan to get back to a launch attempt once we return from the storm is really very straight forward," Leinbach said. "We'll go through a launch pad validation process, that's about a day-long test or so, that's where we do all the connections, data, power and gases, connections from the launch pad to the mobile launch platform. We will be opening the payload bay doors and giving our payload friends a battery boost.
"Then on day two, we will reconnect our ordnance, we need to pressurize our MPS (main propulsion system) and our RCS (reaction control system) tanks. We depressurized those for the roll back, so we'll repressurize those. Then we'll get into our launch countdown. It's going to be a full three-day standard launch countdown."
Pad processing will not take as long as usual because many tasks have already been completed. Rocket fuel for the shuttle's maneuvering jets is already on board, the payload - a new solar array truss for the international space station - is already in the cargo bay and the crew has already completed a dress-rehearsal countdown.
"So those things do not have to be re-performed and that saves us a heck of a lot of time," Leinbach said. "So the short answer is, I feel good about it. I can't give you a firm date yet. When we have a better plan, I'm sure we'll advertise it to you."
The current Sept. 7 end of the shuttle's launch window is the result of three factors: The need to launch into the plane of the space station's orbit; the desire to launch in daylight for photo documentation of the shuttle's heat shield and external tank; and the need to complete the docked phase of the mission before launch of a Russian Soyuz rocket carrying the station's next full-time crew.
For Atlantis to launch past Sept. 7, the Russians would have to agree to a Soyuz launch delay that, in turn, would force the outgoing crew of the station to land in pre-dawn darkness, something the Russians don't want to do.
Earlier today, Mike Suffredini, space station program manager at the Johnson Space Center in Houston, said more discussions were planned but as of today, Sept. 7 was the cutoff. Cain seemed to imply at one point that Sept. 8 might already be on the table, but that could not be confirmed.
For readers interested in a look ahead, here is the shuttle's flight plan assuming a launch at 12:29 p.m. on Sept. 6. The timing of key events will change slightly as NASA revises the shuttle's rendezvous profile and the crew's timeline between now and then, but the times below provide a ballpark look at when major activities would occur (all times in EDT and mission elapsed time):
04:15 p.m., 08/29/06, Update: NASA considers relaxing daylight launch constraint if Atlantis misses September window
If the shuttle Atlantis fails to get off the ground before the Sept. 7 end of its current launch window - a scenario that could delay the flight to late October - NASA managers may reconsider an earlier decision to only launch in daylight to ensure photo documentation of the ship's heat shield and external tank, officials said today.
The issue became somewhat moot in the near term after NASA managers reversed an earlier decision to haul Atlantis off the pad because of concern about high winds from tropical storm Ernesto.
If Atlantis can ride out the storm at pad 39B without any major problems, NASA should have one or two shots at getting the flight off the ground before Sept. 7 without changing any existing requirements.
Had NASA pressed ahead with rollback, however, the agency would have lost any chance of launching Atlantis before the end of the window without help from the Russians or a change in the lighted launch requirement.
While NASA could launch as late as Sept. 13 based on lighting alone, any launch past Sept. 7 would require the Russians to delay launch of a Soyuz rocket carrying the next station crew and that, in turn, would force the outgoing station crew to land in pre-dawn darkness.
The Russians don't want to do that and while discussions are ongoing, it appears extremely unlikely they will change their position.
The next lighted launch opportunity for Atlantis is a two-day window opening Oct. 26. But if Atlantis doesn't' get off before Sept. 7, and if NASA managers give up the lighting requirement, the shuttle could take off shortly after the Soyuz carrying the outgoing station crew departs from the lab complex.
Assuming NASA uses up the existing window, the Soyuz would take off Sept. 18 and dock with the station two days later. The outgoing station crew would land Sept. 29. Under that scenario, the earliest Atlantis could launch, in predawn darkness, would be late September or, more likely, early October.
"We want to work the technical discussion of lighting and see where it leads us and we'll keep you informed as we get there," Hale told reporters less than an hour before Atlantis reversed course and headed back to the pad.
In the wake of the 2003 Columbia disaster, NASA managers said the first two return-to-flight missions would be launched in daylight to ensure good photo documentation of the heat shield and external tank insulation. After a large piece of foam insulation fell off the shuttle Discovery's tank during the first post-Columbia mission, Hale extended the daylight launch requirement to one additional mission - STS-115 aboard Atlantis.
After standing down a year to make more changes to the tank's insulation, Discovery flew again last July and its tank performed well. No major pieces of foam came off during passage through the dense lower atmosphere when the most critical damage can occur.
But Discovery's tank, like the one being used by Atlantis, features buildups of foam insulation called ice-frost ramps that are considered dangerous. NASA is working to redesign the ramps, but a fix will not be in place until next year.
From Hale's perspective, the lighted launch requirement is directly tied to the need to gather data that can help engineers improve the tank design. But with the possibility of a long delay if Atlantis misses the September window, Hale has asked engineers to revisit the lighting issue.
"We have kicked off a study to review our requirement for lighting," Hale said. "This will be the third flight that we have asked for lighting and going into STS-115, our position was that having successful data and consistent performance we would drop that requirement for subsequent flights and fly at night as required.
"So we have asked ourselves now, what are the rationales for our requirements, have we exceeded some of it? For example, if we wait for the next lighted launch window, which is very late in October, I think it's the 26th of October, one of the things we wanted to potentially get was to roll data that you'd get from the lighted pictures of the ET into the ice-frost ramp redesign. We're working that very hard.
"We expect to finalize our design and make some engineering decisions about the first of October," he said. "So at that point, getting data late in October is not very useful to inform those engineering decisions. I'm just using that as an example of the kind of review we're going forward with to say do we, in fact, still want to hold firm to a day-lit launch requirement for this particular flight? Or is it possible that we would be willing to launch with less than optimum lightning conditions?"
Hale said he expects a preliminary report by the end of next week.
"We have not made a decision, we're just going through the technical review at this point," he said. "We obviously will talk to a lot of folks about that decision before we make it. So lighting, I think, is under discussion."
Hale was asked if his willingness to consider amending a long-standing, if self-imposed, safety guideline in the face of perceived "schedule pressure" might send the wrong signal to the work force. He strongly disagreed and because this issue is so critical to the near-term shuttle launch schedule, here is his complete response:
"The original test flight philosophy was to have two flights with the daylight launch, which was STS-114 and STS-121," he said. "We elected, and it was largely my decision, to extend the daylight planning requirement for one more flight, STS-115. There seemed to be a number of reasons why that would be an interesting and good thing to do.
"But none of which were related to the safety of the flight in progress. Because the safety of the flight in progress, in this case STS-115, is assured by the 100 percent inspection that we do of the thermal protection system of the orbiter before we commit to landing. And it's also backed up with layers of redundancy, with our repair capability that we have worked very long and hard to get together for on-orbit repairs of the thermal protection system. Finally, as a last-ditch effort, (we have) a way to rescue the crew from an extended stay on board the space station if we had suffered large damage and were unable to repair it. So we think we have defense in depth here.
"The question about having a day-lit launch really is to gather data for the future flights after the current one, which is to say STS-116 and subsequent. Now, the principle thing we're doing on the tank is to modify the ice-frost ramps. We have a large group of folks ... working on that redesign. We have done a large number of ground tests, we're getting ready to go back into the wind tunnel with modified designs.
"So we think we're coming to a decision point here in the not very distant future to make final decisions about those modifications, which we are going to start putting on the tank that will fly early next year," he said. "So the question is, are we missing something, is there something in a requirement which we are not thinking about that says that we should stay with the lighted launch requirement?
"We know that if you have for the duration of the shuttle program a requirement to launch in daylight, we cannot fulfill this manifest, it is physically impossible. So at some point, we want to go back to having around-the-clock launch capability. Originally, that was scheduled to be for the STS-115 flight.
"We extended the constraint for one flight because we thought there were some good reasons for it and what I've asked the team to do is go off and examine those reasons and see if they are still applicable. If they are, we will stay with the lighted launch window. If, in fact, we have been overcome by events and they are no longer requirements, they do not inform the redesign for the ice-frost ramps, then perhaps we have a constraint that is overly burdensome and is not providing additional safety to the program and it makes sense then to proceed with a non-lighted launch."
02:55 p.m., 07/16/06, Update: NASA reverses rollback decision, moves Atlantis back to pad with improved forecast
Launch director Mike Leinbach, buoyed by a more favorable forecast for tropical storm Ernesto, ordered engineers to stop the shuttle Atlantis' trip back to the Vehicle Assembly Building today and instead to return to the ship to the launch pad.
The National Hurricane Center now expects Ernesto to bring sustained winds of 45 knots to the Kennedy Space Center Wednesday, with gusts to 60 knots. That's within NASA's safety limits and the protection provided by wind screens and the massive rotating service structure that surrounds the shuttle on the pad.
Atlantis' rollback began at 10:04 a.m. after a long debate about the forecast and whether to ride out the storm at the pad. In the end, Leinbach decided predictions of 65-knot gusts were too much and the slow move began.
Then at 2:45 p.m., the massive crawler-transporter stopped in its tracks, loud speakers along the crawlerway announced the decision to reverse course and at 2:45 p.m., the shuttle began moving back toward pad 39B. Engineers expect to put it back in place by 8 p.m. and to extend the rotating service structure by 8:30 p.m. to provide some level of protection.
It is not at all clear how this decision might affect when Atlantis might be ready for launch. Leinbach said earlier it would take eight days to ready the ship for flight whenever it was returned to the pad from a rollback. Given the impact of Ernesto and other factors, it's not clear whether NASA can complete preparations before time runs out.
10:10 a.m., 08/29/06, Update: Shuttle rollback underway
With tropical storm Ernesto threatening Florida, NASA managers today reluctantly ordered engineers to proceed with plans to move the shuttle Atlantis back to the protection of the Vehicle Assembly Building, a move that likely will delay the flight to late October.
Launch director Mike Leinbach made the decision shortly before 9:45 a.m. after a final weather briefing and a last-minute debate about the possibility of riding out Ernesto at the launch pad.
By keeping Atlantis at the pad, NASA could, in theory, be ready for launch by Sunday or Monday assuming the storm caused no major damage. But with forecasters predicting 50-knot winds Wednesday with gusts to 65 knots, Leinbach and other senior managers decided to err on the side of caution.
Engineers operating a powerful crawler-transporter then jacked up Atlantis' mobile launch platform and began inching toward the VAB at 10:04 a.m.
The 4.2-mile trip from the launch pad to high bay 2 on the west side of the Vehicle Assembly Building was expected to take about 10 hours to complete. That's two hours faster than originally expected because of a decision to run the crawler at its top speed of 1 mph.
The slow speed is not surprising given the enormous mass of the shuttle and its mobile launch platform. The two-story MLP, which measures 160 feet by 135 feet, weighs 9.25 million pounds. With an unfueled space shuttle attached, the weight climbs to 12 million pounds.
The original plan called for moving Atlantis to high bay 3 on the east side of the VAB closest to the launch pad. That would have reduced the travel time to about eight hours. But problems with NASA's only other crawler prevented engineers from moving another MLP out of the way Monday. As a result, Atlantis will have to make a longer trip to the far side of the VAB.
The forecast for today's move calls for an increasing chance of showers as the day wears on with the odds of thunderstorms climbing to 30 percent between 5 p.m. and 8 p.m. Between 8 p.m. and 10 p.m., there's a 40 percent chance of thunderstorms, 60 percent between 10 p.m. and midnight.
At the launch pad, the shuttle is shielded by a very effective lightning protection system. A 100,000-amp lightning strike at the pad last Friday caused no major damage. But during the roll back to the VAB, the shuttle is exposed to the elements and NASA hopes to avoid thunderstorms if at all possible.
Today's decision to roll the shuttle back to the VAB was a critical milestone for NASA because it all but eliminates any chance of launching before the Sept. 7 end of the shuttle's current launch window.
The end of the launch window is defined by NASA's desire to launch in daylight for photo documentation of the shuttle's heat shield and external tank and by Russian plans to launch a Soyuz rocket by Sept. 18 to deliver a fresh crew to the international space station.
Based on lighting alone, Atlantis could launch as late as Sept. 13. NASA would need at least eight days to ready the shuttle for flight after a roll back out to the launch pad after Ernesto passes and if lighting alone was the limiting factor, at least a few launch attempts would be possible.
But any launch past Sept. 7 would force the Russians to delay the Soyuz beyond Sept. 18, resulting in a dead-of-night landing for the space station's outgoing crew. The Soyuz recovery team is operating under new civilian management for the first time and so far, Russian space managers, citing flight safety, have refused to move the launch date past the 18th.
If that holds up, NASA will be forced to delay Atlantis' launch on a long-awaited space station assembly mission until a two-day window that opens Oct. 26. The next lighted window after that is a one-day opportunity Dec. 23.
NASA managers already are discussing ways to expand the October window slightly, by either relaxing some of the lighting requirements or changing station operations to loosen temperature constraints.
As it now stands, a launch by Atlantis in October would almost certainly delay a planned Dec. 14 flight by the shuttle Discovery to mid January. That, in turn, would delay three critical post shuttle-undocking spacewalks by the station crew to February in a ripple effect that could have implications for other downstream flights.
But in the near term, Ernesto is the center of NASA's focus as engineers haul Atlantis back to the VAB and prepare the launch pad and other facilities for tropical storm-force winds Wednesday.
04:00 p.m., 08/28/06, Update: Crawler problems add hours to rollback time
Problems with one of NASA's ponderous crawler-transporters will force engineers to take the shuttle Atlantis to the far side of the Vehicle Assembly Building Tuesday if a rollback from the launch pad is ordered because of tropical storm/hurricane Ernesto. The change in plans will add three hours or so to the time necessary to get Atlantis out of harm's way.
If rollback is, in fact, ordered, NASA will be in a race against the clock to get Atlantis moved before any thunderstorms develop along Florida's space coast. NASA safety rules forbid moving a shuttle "stack" in winds above 40 knots or if lightning is present within 20 nautical miles.
At the launch pad, a shuttle and its propellant-loaded solid-fuel boosters are protected from the weather by a lightning protection system and rain barriers that effectively surround the orbiter. No such protection is available during a roll to or from the pad.
NASA has not yet committed to hauling Atlantis off pad 39B, but Ernesto's projected track and the prospect of tropical storm- or hurricane-force winds Wednesday could leave the agency with little choice. But a final decision is not required until Tuesday morning, when a crawler-transporter picks up the shuttle's mobile launch platform.
Assuming a rollback is ordered, NASA had planned to move Atlantis into high bay 3 in the VAB, which faces the launch pad, after moving another mobile launch platform out of the way. A crawler-transporter moved that MLP out of the bay earlier today, but had to put it back after hydraulic problems developed.
The only available bay for Atlantis, high bay 2, is on the opposite side of the VAB. Because more turns and maneuvering are required to reach high bay 2, Atlantis' trip, if ordered, will take up to three hours longer to complete. If ordered, the trip would begin around 9 a.m. and take about 11 hours or so to complete.
The forecast for Tuesday calls for winds out of the southeast at 8 knots in the morning, increasing to 14 to 20 knots in the afternoon. After 8 p.m., the winds will jump to 17 to 25 knots, still well below the 40-knot limit.
There is a 30 percent chance of rain showers in the morning with a 20 percent chance of thunderstorms, a forecast that currently extends to 5 p.m. Tuesday. Between 5 p.m. and 8 p.m., the chance of showers increases to 40 percent with a 30 percent chance of thunderstorms. Between 8 p.m. and 10 p.m., the rain chance goes up to 60 percent with a 40 percent chance of thunderstorms and after 10 p.m., the probability of rain increases to 70 percent with a 60 percent chance of thunderstorms.
"They would like to be moving as soon as they can in the morning so they can be in the barn by eight o'clock," said NASA spokesman George Diller.
If an electrical storm develops during the roll back to the VAB, the safety plan calls for the crawler crew to stop the move and leave the transporter until the storm passes.
07:30 a.m., 08/28/06, Update: Ernesto's track moves eastward; threatens Kennedy Space Center; rollback preps underway (UPDATED at 12:00 p.m. with news conference; quotes and details)
In what amounts to a "perfect storm" of high winds, high stakes and international drama, tropical storm Ernesto threatens to bring hurricane-force winds to the Kennedy Space Center by Wednesday night. NASA managers today ordered engineers to begin work to roll the shuttle Atlantis off its seaside launch pad Tuesday, raising the prospect of a lengthy launch delay.
For NASA, which is poised to resume space station assembly after a three-and-a-half year hiatus, rollback is a last-resort option that would end any chance of getting Atlantis off the ground before the launch window closes Sept. 7. If that scenario plays out, launch could slip to late October when a brief two-day lighted window is available.
An October launch, in turn, almost certainly would force NASA to delay a planned December flight by the shuttle Discovery to January at the earliest in a ripple effect with consequences for downstream flights.
But NASA managers are holding open the option of calling off Atlantis' rollback if Ernesto veers away from Florida or weakens significantly. The storm's track has consistently moved eastward and now is predicted to make landfall around Miami and move up Florida's east coast before heading out to sea south of the Kennedy Space Center. The track could end up missing Florida altogether when all is said and done.
But based on the current prediction and the near certainty of high winds at the spaceport later this week, NASA managers plan to begin moving Atlantis from pad 39B to the protection of the Vehicle Assembly Building as early as 8 a.m. Tuesday.
"We made a decision this morning to start in earnest our rollback preparations to move us back to the VAB," said Launch Director Mike Leinbach. "The first thing on the agenda for us is off loading the reactants (liquid oxygen and hydrogen) for our fuel cell system. That's in work, that should be done probably about noontime today."
Once the pad reopens for normal work this afternoon, engineers will begin disconnecting ordnance on the vehicle in preparation for rollback. Leinbach said the team can stop rollback preparations pretty much at any point between now and Tuesday morning based on the progress and development of Ernesto.
But with thunderstorms expected at the Kennedy Space Center Tuesday afternoon, a final decision will have to be made late tonight or first thing Tuesday morning to ensure Atlantis can get back to the VAB before the weather deteriorates. The 4.2-mile trip takes more than six hours to complete and the shuttle would be exposed to the elements between the pad and the VAB.
"We had been targeting approximately two o'clock for first motion," Leinbach said. "We'd like to get off the pad tomorrow morning if at all possible. ... It's my hope and expectation that we'll be able to get off the pad tomorrow morning first shift sometime, probably around eight o'clock or so, maybe 10. ... Based on tomorrow afternoon's local weather, we'd much rather be back in the VAB earlier than later."
NASA's safety rules forbid moving the unprotected orbiter off the pad in winds higher than 40 knots or if lightning is expected within 20 nautical miles.
NASA managers considered ordering a rollback Sunday night but deferred a decision to today believing they had time before the onset of 40-knot winds. By deferring a decision, NASA kept open the possibility of launching Atlantis Tuesday on a space station assembly mission if Ernesto's track or strength dramatically changed. That option is now closed.
Atlantis' launch window closes Sept. 7, based on a desire to launch in daylight for photo documentation of the shuttle's heat shield and external tank and because of conflict with launch of a Russian Soyuz rocket carrying the space station's next crew.
While the shuttle can launch as late as Sept. 13 from a lighting standpoint, any launch past Sept. 7 would force the Russians to delay the Soyuz launch and, more important, delay the return to Earth of the station's outgoing crew. A shuttle launch on Sept. 7 would result in a pre-dawn landing for the returning Soyuz.
Every day past Sept. 7 would move the landing earlier in the day and Russian managers want to avoid a dead-of-night touchdown because the recovery team will be conducting its first operation under new civilian management.
A rollback would use up NASA's available launch window, barring a concession from the Russians to delay the Soyuz launch. Even if Ernesto passes without causing major damage, it would take NASA at least eight days to ready the ship for flight after rolling back out to pad 39B.
If Atlantis remains at the launch pad, either because of high winds preventing a rollback or because the storm changes strength or direction, NASA managers believe it's unlikely any launch attempts could be made before Saturday or Sunday at the earliest.
"All I can give you is ballpark right now," Leinbach said. "If the storm were to change course significantly, and intensity significantly (and) we're comfortable riding the storm out with Atlantis at the launch pad, we'd have to wait for the storm to pass, we'd have to get back into the ordnance connects if we decide to disconnect this afternoon, and then get back into the launch countdown. ... The best I can tell you is, if we stay at the launch pad with the vehicle, which right now doesn't look likely, the best we can do for launch is sometime late this weekend. You can all interpret that as you please. I do not have a date for you.
"If we roll back to the VAB, that's a significantly different beast," he said. "Once we get back out to the launch pad after the rollback, it's a minimum of eight days to a launch. It's all dependent on what happens to the storm and how long we're in the VAB if we do roll back."
Said LeRoy Cain, chairman of NASA's Mission Management Team: "If we actually roll the vehicle back to the VAB ... we can't get to a T-zero before Sept. 7."
Space station program manager Mike Suffredini opened discussions with the Russians today about the possibility of a launch past Sept. 7 and while NASA has not made any official comment, that does not appear to be a likely scenario. Delaying the Soyuz just two days, for example, would move the returning Soyuz's landing time several hours deeper into darkness.
As for relaxing the lighted launch requirement to open up more opportunities after the Soyuz flight, Bill Gerstenmaier, chief of spaceflight for NASA, said Sunday the agency considers photo documentation of the shuttle's tank and heat shield a high priority.
But if Atlantis misses the September launch window, NASA would be faced with the prospect of just three lighted launch days between then and the end of the year - Oct. 26-27 and Dec. 23. The next lighted launch window after that opens Feb. 19.
Flight planners may be able to expand the October window by a day or two, but that remains to be seen. In any case, a launch of Atlantis in October almost certainly would push a planned Dec. 14 launch of shuttle Discovery into January at the earliest.
Assuming Atlantis gets off this fall and no problems are found with the ship's external tank foam insulation, NASA likely will relax the daylight launch constraint. If so, and if Atlantis could be turned around fast enough to serve as a rescue vehicle, Discovery next launch window would open around Jan. 13.
But a new factor enters the planning mix for that flight. Because the astronauts plan to activate the station's main ammonia cooling system, launch cannot take place if the angle between the sun and the plane of the station's orbit is below 50 degrees or so. While that will limit the available launch windows in January, it will not be as restrictive as the lighting constraints currently in place.
09:00 p.m., 08/27/06, Update: NASA defers rollback decision to Monday; Tuesday launch still possible
NASA managers met Sunday evening and agreed to wait until Monday morning to make a decision on whether to roll the shuttle Atlantis back to the Vehicle Assembly Building, preserving for now the option of launching the ship Tuesday on a space station assembly mission.
"We plan to get together early tomorrow morning and take a final look," said LeRoy Cain, chairman of NASA's Mission Management Team. "Based on the current timetable, we plan to make our decision one way or the other by 7 a.m. tomorrow morning."
At issue is the progress of tropical storm/hurricane Ernesto and an updated forecast that calls for 40-knot winds at the Kennedy Space Center early Wednesday. A rollback would take 42 hours, so NASA could afford to wait until Monday morning before making a decision.
If Ernesto weakens or its path changes, NASA could simply press ahead and make a run at launching Atlantis Tuesday at 3:42 p.m. Engineers have concluded there is no need to conduct time-consuming booster and self-destruct system tests in the wake of a launch pad lightning strike Friday. Forecasters say there is a 70 percent chance of acceptable weather Tuesday.
But if Ernesto continues to threaten, NASA's Mission Management Team will order engineers to begin preparing for rollback early Monday.
"With the current storm predictions, it would take a relatively significant change from the current forecast we're seeing to prevent us from going into rollback preparations," Cain said. "If we see a change like that, then we'll press on. If we don't, then we'll be getting into our rollback preparations."
Before Atlantis can be moved from the launch pad, engineers must first drain liquid oxygen and hydrogen from the ship's fuel cell system, a hazardous operation that requires the launch pad to be evacuated. After that, a variety of pyrotechnic charges would have to be disconnected and Atlantis would not be ready to roll until Tuesday afternoon.
Draining the fuel cell system would preclude any chance of launching Tuesday. But if the forecast changes before rollback begins, NASA could keep Atlantis at the launch pad and avoid a long delay that would threaten to use up the available launch window. In that case, subsequent launch attempts could be made after Ernesto passes and after engineers reload the shuttle's fuel-cell system.
If a rollback is ordered, Atlantis likely could not be returned to the launch pad until Saturday or Sunday. From that point, engineers would need at least eight days to ready the ship for launch. That would prevent any chance of launching Atlantis by Sept. 7, the current end of the launch window.
NASA managers said earlier Sunday a rollback decision was needed by midnight based on earlier predictions that high winds could reach the Florida spaceport Tuesday night. While the shuttle can endure, in theory, 70-knot winds at the launch pad where wind and lightning protection is available, a shuttle cannot be rolled back to the VAB in winds higher than 40 knots.
"We're going to get some effects from the storm at the Kennedy Space Center," said launch director Mike Leinbach. "It remains to be seen how bad those effects are and that's the risk trade we make when these storms threaten us. Do we stay at the pad and accept some amount of wind? Or do we expect to have those levels of winds that would harm the orbiter and we have to roll back and protect her?"
The goal of Atlantis' mission is to deliver a new set of solar arrays to the international space station. To reach the station, the shuttle must launch into the plane of its orbit during periods when the angle between that plane and the sun doesn't result in lower-than-allowable temperatures. Such temperature problems occur when the so-called beta angle drops below 50 to 60 degrees.
In this case, the launch window also is affected by a self-imposed NASA requirement to launch in daylight for photo documentation of the shuttle's heat shield and external tank. Based on all three constraints, Atlantis' launch window extends through Sept. 13.
The Russians plan to launch a fresh crew to the space station in mid September and to bring the lab's current crew home 11 days later. The Russians do not want to launch past Sept. 18 at the latest to avoid a dead-of-night landing for the returning station crew. This will be the first Soyuz recovery carried out under civilian management.
As it now stands, Atlantis must launch by Sept. 7 to complete its docked mission and depart before arrival of the Soyuz.
Mike Suffredini, space station program manager at the Johnson Space Center, said Sunday he planned to open discussions with the Russians early Monday about possible options.
"My opinion is, I think the system is fairly robust for night landings but again, you're weighing a risk to the crew with the schedule to go fly," he said. "We're responsible for shuttles. It's up to us to say we feel comfortable. They're responsible for Soyuz. So a really big part of this is not my opinion on risk trade, but whether they're willing, whether they want to take that risk because they're ultimately responsible for the crew. And just like how we feel about protecting our crews, they feel the same way."
If Atlantis misses the September window, NASA would be faced with the prospect of just three lighted launch days between then and the end of the year - Oct. 26-27 and Dec. 23. The next lighted launch window after that opens Feb. 19, and that assumes NASA would launch with a beta angle of less than 50 to 60 degrees.
Asked if NASA might be willing to relax the daylight launch constraint to open up more opportunities, Bill Gerstenmaier, NASA's senior space flight manager, said "we really want to keep the daylight launch" to ensure photo documentation of the shuttle's external tank, especially so-called ice-frost ramps that are still considered potentially dangerous.
"We really want to see how the ice-frost ramps perform, we really want to gather this data," said Bill Gerstenmaier, NASA's administrator for space flight. "So I think it's a pretty strong requirement. We may kind of nibble around the edges, do we need umbilical camera lighting? Do we need lighting during ascent? Are there other things we can do that might allow us to shave a little bit one way or the other? But I think from where we are really in this flight test mode, this data's pretty important to us and it's going to carry a pretty high priority."
04:20 p.m., 08/27/06, Update: Rollback options debated; launch windows reviewed
NASA managers plan to meet tonight to make a decision on whether to proceed with an attempt to launch the shuttle Atlantis Tuesday on a space station assembly mission or roll the spacecraft back to the protection of the Vehicle Assembly Building because of hurricane Ernesto.
As it now stands, Atlantis has at least a shot at getting off the ground Tuesday at 3:42 p.m. if engineers can resolve lingering questions about the possible effects of a Friday lightning strike on critical booster and self-destruct systems.
The forecast for Tuesday calls for showers in the area and if NASA failed to get Atlantis off, engineers would not have time to get the shuttle back to the VAB before high winds from Ernesto reached the area. As of this writing, 40-knot winds are expected at the Kennedy Space Center by Thursday afternoon.
That's important because NASA safety rules forbid moving a shuttle from the launch pad if sustained winds of 40 knots or greater are expected. At the launch pad, a shuttle is protected somewhat by rain barriers and a lightning protection system. While NASA specifications say a shuttle can endure near hurricane-strength winds at the pad, the ship's external tank is exposed to the elements, as are the spacecraft's twin solid-fuel boosters.
NASA has moved shuttles off the launch pad 15 times in program history, four of them due to threatening tropical storms or hurricanes.
Computer models predicting the path and forward velocity of Ernesto are "drifting a little more to the right (east) now, a little more up central Florida," said Bill Gerstenmaier, NASA's senior spaceflight manager. "So that's a concern to us from a rollback standpoint. We'd like to have the vehicle back to the (Vehicle) Assembly Building before high winds hit the Cape. So that forces us to start taking some actions pretty soon.
"We really have two competing objectives," he said. "One, we want to get the vehicle ready to go fly. The other objective is we want to get the vehicle ready to roll back to the VAB. And they are not compatible. Those are two totally different objectives. And at some point in the sequence you have to give up on either one or the other. That point in time hasn't occurred yet, but it's coming this evening and we're going to have to make a decision."
If the decision is to move Atlantis back to the VAB, engineers would first have to drain on-board oxygen and hydrogen supplies, a hazardous operation that requires workers to leave the launch pad, and then make critical disconnections.
The entire process, from the time the decision was made to Atlantis reaching the VAB, would take about 42 hours, officials said, putting Atlantis back in the VAB by Tuesday evening.
"Probably by about midnight tonight we have to decide one way or the other which way we're going and we can no longer continue to protect both options," Gerstenmaier said. "So we will protect both options as long as we can unless the data changes. If the data changes, we'll delay the decision as long as the data allows us to delay the decision."
But based on Ernesto's current track and the convergence of several computer models, it would appear NASA will not be able to delay a decision much longer.
The goal of Atlantis' mission is to deliver a new set of solar arrays to the international space station. To reach the station, the shuttle must launch into the plane of its orbit during periods when the angle between that plane and the sun doesn't result in lower-than-allowable temperatures. Such temperature problems occur when the so-called beta angle drops below 50 to 60 degrees.
In this case, the launch window also is affected by a self-imposed NASA requirement to launch in daylight for photo documentation of the shuttle's heat shield and external tank. Based on all three constraints, Atlantis' launch window extends through Sept. 13.
The Russians plan to launch a fresh crew to the space station in mid September and to bring the lab's current crew home 11 days later. The Russians do not want to launch past Sept. 18 at the latest to avoid a dead-of-night landing for the returning station crew.
That means Atlantis must launch by Sept. 7 to complete its docked mission and depart before arrival of the Soyuz.
Gerstenmaier said today a preliminary assessment shows Atlantis could be rolled back to the VAB and back out to the pad after Ernesto passes in time to support a launch try by Sept. 7 or 8. But engineers say a more realistic estimate is eight to 10 days between rollout and launch.
If Atlantis misses the September window, NASA would be faced with the prospect of just three lighted launch days between then and the end of the year - Oct. 26-27 and Dec. 23. The next lighted launch window after that opens Feb. 19, and that assumes NASA would launch with a beta angle of less than 50 to 60 degrees.
Asked if NASA might be willing to relax the daylight launch constraint to open up more opportunities, Gerstenmaier said "we really want to keep the daylight launch" to ensure photo documentation of the shuttle's external tank, especially so-called ice-frost ramps that are still considered potentially dangerous.
"We really want to see how the ice-frost ramps perform, we really want to gather this data," he said. "So I think it's a pretty strong requirement. We may kind of nibble around the edges, do we need umbilical camera lighting? Do we need lighting during ascent? Are there other things we can do that might allow us to shave a little bit one way or the other? But I think from where we are really in this flight test mode, this data's pretty important to us and it's going to carry a pretty high priority."
12:00 p.m., 08/27/06, Update: Monday launch ruled out
NASA managers have officially ruled out any possibility of launching the shuttle Atlantis on Monday. A launch attempt Tuesday is possible, but it's not yet known whether additional testing will be required to recover from a Friday lightning strike at the launch pad or whether hurricane Ernesto might force NASA to haul Atlantis off the launch pad.
A series of meetings is planned today to discuss the weather, launch and rollback options. Updates will be posted here as warranted.
09:40 a.m., 08/27/06, Update: Monday launch no longer appears possible; Ernesto takes turn toward Florda
NASA managers debating launch options for the shuttle Atlantis have a new issue to contend with: Hurricane Ernesto, now predicted to strike the west coast of Florida late this week just north of Tampa.
Engineers at the Kennedy Space Center have been told Atlantis' launching is off until at least Tuesday, but NASA has not yet made any official announcement. A launch Monday or Tuesday assumes time-consuming tests of ordnance and control circuitry in the shuttle's solid rocket boosters and self destruct system in the wake of a lightning strike Friday are not required (see the 1:50 a.m. status report for details). The latest forecast for Tuesday is not favorable.
Depending on Ernesto's eventual course, the timing of its passage and what needs to be done to recover from the lightning strike, NASA managers could be forced to consider hauling Atlantis back to the protection of the Vehicle Assembly Building, a move that would use up most of the shuttle's September launch windows.
NASA wants to launch Atlantis in daylight for photo documentation of the shuttle's external tank and heat shield. If the ship isn't off the ground by Sept. 13, NASA will be faced with the prospect of just three lighted launch days between then and the end of the year: two in late October and one in December.
Complicating the picture, launch tries between Sept. 7 and 13 would require agreement by the Russians to delay launch of a Soyuz capsule carrying the space station's next crew. A shuttle launch past Sept. 7 would require a dead-of-night landing for the returning station crew and the Russians want to avoid that because this will be the recovery team's first landing operation since a recent switch to civilian management.
NASA's Mission Management Team plans to meet at 1 p.m. and a news conference is expected later in he day. Updates will be posted here as new information becomes availabe.
01:50 a.m., 08/27/06, Update: MMT defers decision on possible booster, range safety tests
NASA's Mission Management Team decided early Sunday to continue testing and analysis to assess the possible effects of a launch pad lightning strike Friday on the shuttle Atlantis' solid-fuel booster and self-destruct systems. A Monday launch attempt remains feasible for now, sources said, but only if the community agrees time-consuming tests to verify the health of booster and range safety pyrotechnic systems are not needed. If the tests are required, launch likely would slip to mid week or later.
The Mission Management Team plans to meet again at 6 p.m. Sunday to discuss the progress of the analysis and to make a decision on how to proceed.
The lightning bolt hit Friday, pumping some 100,000 amps of current through the launch pad's lightning protection system. Lightning strikes typically generate 5,000 to 20,000 amps of current and the bolt Friday is one of the strongest on record at the Kennedy Space Center.
Telemetry showed a very small "spike" in one of the shuttle's electrical buses and a larger surge in the circuity associated with a launch pad pyrotechnic device used to disconnect a hydrogen vent arm from the shuttle's external tank.
Concern that induced currents could have affected other sensitive electrical systems on the pad or in the shuttle, Mission Management Team Chairman LeRoy Cain on Saturday ordered Atlantis' launch delayed for at least 24 hours, from Sunday to Monday at 4:04 p.m., to give engineers a chance to assess their systems.
Later Saturday, representatives of the shuttle booster program and the range safety system raised concerns that prompted a late night meeting of the Mission Management Team.
Atlantis was powered up when the lightning struck and an analysis of the powered systems shows no problems. But the boosters were not powered and engineers have no data to assess the health of critical components. At issue is whether the strike might have affected circuity that fires explosive charges used during booster ignition and separation. Similar concerns were raised by Air Force range safety officers about the shuttle's self-destruct system.
To test those circuits and their pyrotechnic initiator controllers, or PICs, engineers would first have to drain liquid oxygen and hydrogen from the shuttle's fuel cell system and open the ship's aft compartment. Ordnance would have to be disconnected and then reconnected as part of the verification process. Then engineers would have to close out the aft and reload the shuttle's fuel cell supplies to ready the ship for launch.
If such tests are ordered, sources said early today, launch likely would be delayed until late this week.
But it may be possible to clear the PIC systems without disconnecting the ordnance based on more detailed analysis of shuttle grounding and response to electrical transients. If that turns out to be the case, NASA could, in theory, press ahead with launching Atlantis Monday.
But as of this writing, it is not clear when a decision to pick up the countdown would have to be made. Updates will be posted here as warranted.
08/26/06: NASA managers discuss additional tests
NASA managers are meeting tonight to discuss whether or not to conduct additional tests to make sure a lightning strike Friday didn't cause any problems with the shuttle Atlantis' solid-fuel booster rockets. If such tests are ordered - and the booster project team is making that recommendation - launch could be delayed until the middle of the week, sources said this evening. But no final decisions have been made.
The lightning bolt hit a mast atop the shuttle's launch gantry at pad 39B Friday afternoon, sending a 100,000-amp current through the launch pad's lightning protection system. Telemetry from the shuttle showed a small spike in one of Atlantis' electrical buses and a larger spike in circuitry associated with a pyrotechnic device used to separate a hydrogen vent arm from the side of the ship's external fuel tank at launch.
NASA's mission management team decided today to scrub a launch attempt Sunday, for at least 24 hours to Monday, to give engineers time to evaluate the data and conduct additional tests to make sure no induced currents caused problems with electrical systems in the shuttle or at the launch pad.
The shuttle's twin solid-fuel booster rockets use pyrotechnic initiator controllers, or PICs, to ignite explosive ordnance in a variety of applications, including the rockets' separation system and the shuttle's self-destruct, or range safety, system. Sources said the shuttle booster project and Air Force range safety officers recommended conducting an end-to-end test to verify the lightning strike did not cause any problems.
Those tests would delay launch until Wednesday at the earliest, sources said, but that could not be immediately confirmed.
A NASA spokesman said engineers at the launch pad were gearing up to unload liquid hydrogen and oxygen fuel cell supplies from Atlantis to clear the way for the tests if the mission management team decides the additional work is needed.
Because of a self-imposed requirement to launch in daylight, and to avoid conflict with an upcoming Russian Soyuz mission to the international space station, Atlantis must get off the ground by Sept. 7 or the flight will face a significant delay. Only two lighted launch opportunities are available in October and only one in December.
This status report will be updated as information becomes available.
08/26/06: Lightning strike one of most powerful on record
The lightning bolt that hit launch pad 39B Friday was one of the most powerful on record at the Kennedy Space Center, sending some 100,000 amps of current through the lightning protection system, officials said today. While the lightning protection system worked, shielding the shuttle Atlantis from a direct hit, engineers are concerned about induced currents that showed up in a brief spike in one of the shuttle's main circuits and another in a launch pad pyrotechnic system.
The spike in the shuttle electrical system was very small and within allowable limits. But no such spikes were expected, an official said, prompting engineers to question whether it might have caused any problems.
At the same time, telemetry indicated a spike in the circuitry associated with a pyrotechnic device that releases a hydrogen vent arm from the side of the shuttle's external tank at liftoff. Engineers inspecting the pad later reported a burning smell in the area of the gaseous hydrogen vent arm, but no obvious signs of damage were seen.
LeRoy Cain, chairman of NASA's Mission Management Team and director of shuttle integration at the Kennedy Space Center, delayed Atlantis' launch for at least 24 hours, from Sunday to Monday at 4:04:18 p.m., to give engineers time to inspect the vent arm system and to carry out additional tests and analyses.
The MMT will meet again at 10 a.m. Sunday to hear an update from the engineering community and to make a decision about whether to proceed to launch Monday or order an additional delay. As of this writing, it's not at all clear how that discussion might go.
Video of the lightning strike at pad 39B showed a large bolt hitting the mast atop the shuttle gantry that anchors the pad's lightning protection system. The shuttle wasn't hit and other than the slight 20-millisecond spike in the shuttle electrical bus, and the concern about the hydrogen pyrotechnic device, there are no other known problems.
"I did press pretty hard to see if it made sense in any way, shape or form to reconvene the team later today to attempt to see if we might be able to still have a viable launch opportunity tomorrow," Cain said. "And based on everything I heard, it was pretty clear to me that we need to let the folks go off and look at their data. So that's what we're going to do.
"We have a launch period here that allows us to go do that. We need to make sure we have a good ground and flight system. So the mission management team will reconvene tomorrow morning at 10 a.m. and we'll see where we are."
The goal of the 116th shuttle mission is to deliver a $372 million solar array truss segment to the international space station, a complex assembly task requiring three spacewalks to complete.
The shuttle's launch window, based on a requirement to launch in daylight and to avoid conflight with a Russian Soyuz launch, runs through Sept. 7. Atlantis' fuel cell system has enough on-board liquid oxygen and hydrogen for launch attempts Monday, Tuesday and Wednesday, although NASA does not usually make three attempts in a row.
After that, NASA managers would have to discuss a variety of options based on when the shuttle's fuel cell supplies would need to be topped off to preserve the option of extending the mission in orbit if necessary. Before today's scrub, NASA's launch strategy called for seven launch tries between Sunday and Sept. 7.
08/26/06: Launch delayed 24 hours
NASA managers today delayed the launch of shuttle Atlantis from Sunday to at least Monday to give engineers more time to carry out tests after lightning hit the launch pad Friday.
Launch is now targeted for 4:04 p.m. Monday, assuming engineers can finish their troubleshooting in time. The forecast for Monday calls for an 80 percent chance of good weather, but it's not yet clear if the inspections will be finished in time. A management meeting to review the shuttle's launch readiness is scheduled for 10 a.m. Sunday.
At least one lightning bolt hit a giant lightning rod atop the gantry at pad 39B Friday during a sudden thunderstorm. Sources said multiple strikes were noted during the storm, but it's not yet known if anything was damaged. Engineers need time to complete tests to make sure the electrical activity didn't affect any of the shuttle's critical systems, from on-board electronics to various pyrotechnic devices on the orbiter and at the launch pad.
NASA plans a news briefing later this afternoon and this status report will be updated as soon as possible thereafter.
08/26/06 Update: Sunday forecast worsens; lightning checks still in work; fuel cell loading complete
The shuttle Atlantis' countdown is back on track today after delays Friday because of stormy weather. More afternoon storms are expected today and again tomorrow, prompting forecasters to predict a 60 percent chance of weather that would block the shuttle's planned 4:30 p.m. Sunday launch on a space station assembly mission.
Shuttle weather officer Kathy Winters said a high pressure ridge has not moved north as fast as expected, resulting in sea breeze-driven afternoon storms along Florida's coast. If the ridge moves far enough north, prevailing winds will tend to drive those storms inland but it's too soon to say whether Atlantis's crew will catch a break Sunday.
The outlook for Monday and Tuesday is 80 percent "go."
NASA test director Jeff Spaulding said the launch team completed work to load the shuttle's fuel cell system Friday night, getting the countdown back on track after the work was interrupted earlier in the day. There are no other technical problems at pad 39B, although engineers were still checking various shuttle and launch pad systems after a lightning strike Friday.
"We did have a lightning strike to our pad lightning protection system yesterday," Spaulding said. "We have been performing a number of evaluations and walkdowns. Those evaluations are ongoing and engineers are still evaluating whether there's any additional work that will be required. So far, it looks favorable."
In the Caribbean, meanwhile, tropical storm Ernesto continues to develop and the National Hurricane Center predicts it will be a full-fledged hurricaine by Monday morning. The storm's track currently takes it into the central Gulf of Mexico, but it's too soon to say what impact, if any, it might have on shuttle operations in Florida or Texas.
NASA managers will review the weather outlook and the shuttle's launch processing during a L-minus one-day meeting starting at 1 p.m.
"In summary, Atlantis, her crew and payload have been waiting nearly four years for this opportunity to fly," Spaulding said. "I'm pleased to announce the vehicle, the launch team and hopefully the weather are ready for tomorrow's launch."
Here is the remainder of the STS-115 countdown. Note that all events up to and including the start of the final hold at the T-minus nine-minute mark are targeted to the opening of the shuttle's 10-minute launch window, typically five minutes earlier than the planned launch time. For countdown calculations, NASA rounds the window open time down to the nearest minute. The release of the final T-minus nine-minute hold, however, is targeted to the actual in-plane launch time, roughly the moment when Earth's rotation carries the launch pad into the plane of the international space station's orbit. All times in EDT.
08/25/06, Update: NASA works around stormy weather; optimistic about Sunday launch try
A lightning bolt struck near the space shuttle Atlantis today as powerful thunderstorms rolled across the Kennedy Space Center, but the launch pad lightning protection system shielded the orbiter and officials said the countdown was on track for a Sunday launch try, weather permitting.
Forecasters are continuing to predict a 40 percent chance of afternoon storms that could block the planned 4:30 p.m. launch time, but the outlook improves to 80 percent "go" Monday and Tuesday. NASA's launch strategy supports four attempts in five days and LeRoy Cain, director of shuttle integration at the Florida spaceport, told reporters "we feel very good about where we are going into the weekend."
NASA started Atlantis' countdown six hours early Thursday, knowing storms today could interrupt work to load liquid hydrogen and oxygen aboard to power the ship's electricity producing fuel cells. Engineers were able to load the oxygen tanks today but work to load hydrogen was delayed when the powerful afternoon storms developed.
Lightning struck a thick wire today that runs to either side of the launch pad as part of its lightning protection system, but launch director Mike Leinbach said telemetry from the shuttle showed no signs of any unusual electrical activity.
As for fuel cell loading, Leinbach said engineers had plenty of time in a long built-in hold to make up for lost time and by tomorrow morning, the countdown was expected to be back on track.
NASA and Air Force meteorologists are monitoring the development of tropical storm Ernesto in the southern Caribbean, but it does not pose any immediate threat to Florida's space coast. If Atlantis gets delayed, however, the storm could come into play next week depending on where it is, where it's going and how strong it might be.
While the Kennedy Space Center likely will be unaffected, the storm could have an impact on Houston and mission control at the Johnson Space Center.
"The storms we're looking at and talking about now are just too, too far away," Cain said. "There's far too much uncertainty in terms of what they will or will not do and quite frankly, I don't see any scenario between here and the launch period, at least for the first several days, where we would have any concerns that would cause us to stand down. I suppose there might be a scenario way out there at the end of our launch period, but I don't envision that at this point."
Atlantis' launch period is defined by the need to launch the shuttle into the plane of the international space station's orbit, temperature constraints based on the angle between that plane and the sun and a self-imposed requirement to launch in daylight for photo-documentation of the shuttle's external tank and heat shield.
All of those factors, plus the upcoming Sept. 14 launch of a Russian Soyuz rocket carrying the next full-time station crew, combine to limit Atlantis' launch opportunities to Aug. 27 through Sept. 7. Within that period, NASA can make seven launch attempts, including four in five days - Sunday, Monday, Wednesday and Thursday - before standing down to top off on-board fuel cell supplies. After that, the agency would have opportunities on Sept. 2, 4 and 6.
While it's too soon to tell whether Ernesto might threaten Houston at some point, NASA has contingency plans are in place to move a small team of flight controllers to the Kennedy Space Center in Florida, if mission control ever had to be evacuated, to oversee shuttle operations.
But under that scenario, a shuttle crew would be ordered home at the first safe opportunity. NASA does not have the ability to oversee shuttle operations from a backup control center, much less carry out the complex commanding required for a mission to the international space station.
The goal of Atlantis' flight is to install a $372 million solar array truss segment that will require back-to-back spacewalks and complex ground commanding to attach and connect to the station's existing power system.
"If we get to the point of having to evacuate the mission control center in Houston, we would not be able to execute the docked mission," Cain said. "We do not have the capability to do a docked mission, certainly not of the complexity of the one we're about to embark on."
Instead, he explained, "we would undock from space station and deorbit at the first, safest opportunity we had and perform entry and landing. And we would leave station in the safest configuration we could and come back and pick up the pieces, if you will, on a subsequent mission."
Assuming a launch on Sunday, Atlantis will dock with the space station Tuesday. The new solar array truss element, known as P3/P4, would be attached the next day using the station's robot arm. Two spacewalkers then would make the electrical connections needed to power heaters and other critical components to keep the new gear alive.
Two more spacewalks are planned to remove launch restraints, deploy the arrays and to activate a massive rotary joint that will keep the giant panels facing the sun. But in a worst-case scenario, P3/P4 could survive in orbit if the shuttle crew was forced to depart after the first spacewalk.
"There is a point at which we're going to leave the truss on orbit," said MIke Suffredini, space station program manager at the Johnson Space Center. "Before that point, the truss can be put back in the payload bay and brought home. I hope we don't do that, that would really be not much fun, but once we get the truss attached and umbilicals hooked up, which happens very early in the docked time frame, we are in a safe configuration. The heaters are working, the hardware would be safe. The shuttle could leave if it needs to do that."
But such a scenario would derail NASA's space station assembly schedule. Work to activate and check out the new truss and solar arrays would have to be carried out by the space station crew, which hasn't trained for the complicated procedures, "so what you're looking at is a pretty long delay while we do all that work," Suffredini said.
NASA managers are hopeful, of course, that it won't come to that. Atlantis' flight is the first in a series of challenging assembly missions that must be carried out in sequence as the agency attempts to finish station construction by the Bush administration's 2010 deadline for retiring the space shuttle.
"This flight has to work for the next flight to occur and the next flight to occur and the next flight to occur," Suffredini said. "The next few have to kind of happen in the right order. If we don't get P3/P4 installed, then I can't go reconfigure the power and cooling system, which I'm doing on the next flight. Which means I can't go bring up the next major power element, which comes on the next flight (after that), and so on and so forth.
"So this flight is critical to our ability to do this truss reconfiguration, this growth to the power system and the central cooling system, which has been dormant on orbit for about three years or so. This is all critical. If we don't do this flight, then the next ones donÕt get to happen until we get this work done. So in the big scheme of things, even though we say we take things one step at a time, this one's a key, we have to let this one occur before the next ones can go."
10:30 a.m., 08/25/06, Update: Countdown on track; weather outlook worsens slightly
The shuttle Atlantis' countdown continues to tick smoothly toward launch on a space station assembly mission. Liftoff is targeted for 4:30 p.m. Sunday. The latest forecast calls for a 60 percent chance of favorable weather, improving to 80 percent "go" Monday and Teusday. The concern Sunday is for possible afternoon thunderstorms within the launch area.
Engineers started the countdown six hours early Thursday in hopes of loading oxygen and hydrogen fuel cell supplies before afternoon thunderstorms develop. NASA test director Pete Nickolenko said that operation should be complete later this afternoon and if storms interrupt the procedure, more than enough "hold" time is available to catch up after the weather passes.
"All our systems are in great shape, the countdown is right on schedule and we're tracking no issues," he said. "All of our teams are ready, they're focused and we're all looking forward to launch on Sunday and the return to (station) assembly."
Shuttle weather officer Kathy Winters said Sunday's launch weather will depend on the movement of a high pressure ridge and whether expected thunderstorms move inland or stay near the coast.
She said forecasters are monitoring tropical depression No. 5 south of Puerto Rico, which may strengthen to hurricane status by Monday, but the storm appears to be heading for the Gulf of Mexico and does not currently pose a threat to the shuttle launch site.
09:00 a.m., 08/25/06: STS-115 mission preview
The shuttle Atlantis is poised for blastoff Sunday on a long-awaited flight to restart assembly of the international space station three years after the Columbia disaster derailed construction. Atlantis and its six-person crew will deliver a $372 million set of solar arrays to the outpost, kicking off the most ambitious series of manned space flights since the Apollo moon program.
"In my opinion, every one of these flights we're flying in the next 12 to 18 months ranks right up there as the most complicated flights we've every flown, including Hubble Space Telescope repair missions," said Paul Hill, mission operations manager at the Johnson Space Center.
"The fact that we're going to go conduct a series of them for 18 months, each one of which is absolutely necessary for the next one to happen, without a doubt makes this the most complicated, most complex 18 months of manned spaceflight we have ever experienced.
Said shuttle commander Brent Jett: "Every crew likes to say boy, this is one of the most complex missions we've every flown. They're all that way. And they'll all be that way until we stop flying in 2010."
With Jett and rookie pilot Chris Ferguson at the controls, the shuttle Atlantis is scheduled to rocket away from pad 39B at the Kennedy Space Center at 4:30 p.m. Sunday, Aug. 27, just six weeks after shuttle Discovery landed to close out the second post-Columbia mission.
The quick turnaround was possible because Discovery came through its flight in excellent condition, with no major systems problems and no major heat shield damage caused by foam insulation falling away from its external fuel tank.
Atlantis will fly with a virtually identical tank, one with foam insulation around nearly three dozen external fittings that is classified as "probable/catastrophic" in NASA's risk matrix. That means there's a 50-50 chance of catastrophic damage over the 100-flight design life of a shuttle.
NASA is developing a redesign for the so-called ice-frost ramps, but it will not be ready for flight until next year. NASA Administrator Mike Griffin approved Discovery's launch last month over the objections of the agency's top safety manager and its chief engineer. Facing a 2010 deadline for completing the space station and retiring the shuttle, Griffin decided the impact of another long delay was worse than flying with what he considered to be an acceptable risk.
This time around, even though the ice-frost ramps remain officially classified as probable/catastrophic, there was no dissent and Atlantis was cleared for launch on the 116th shuttle mission without objection.
Joining Jett and Ferguson aboard Atlantis will be flight engineer Dan Burbank, a former Coast Guard helicopter pilot who flew a real rescue mission in "the perfect storm," Canadian astronaut Steve MacLean, veteran Hubble spacewalker Joe Tanner and Heidemarie Stefanyshyn-Piper, a former Navy salvage diver.
Mounted in the shuttle's cargo bay is one of the heaviest payloads ever launched to the space station, a $371.8 million extension to the lab's main solar array truss that weighs some 34,977 pounds.
Forty-five feet long and 16 wide, the Boeing-designed payload features two new solar arrays and a massive rotary joint that will permit the giant panels to slowly turn like a giant waterwheel to track the sun as the station circles the globe at five miles per second.
The solar alpha rotary joint, or SARJ, is the main component of what NASA calls the P3, or port 3, truss element. The solar arrays, their electronics and cooling radiators make up the P4 truss element. Both are bolted together and NASA refers to the combination as the P3/P4 truss.
"It's been six years since our payload has been at Kennedy," MacLean said when the crew flew to Florida to prepare for blastoff. "It's been four years since Atlantis has been in preparation (for launch) and for us as a crew, it's been four and a half years as well. And finally, on Sunday, we're going to get to walk out to the pad for launch.
"For me, walking out to the pad on Sunday will be much like walking into an Olympic stadium for your athletic event. Many countries will be participating in a spirit of international cooperation and our families and our friends who believe in what we do will be in the front seats of the stadium. So I invite you all to watch what we do over the next week. It will be exciting. It's complex what we do, it's not easy. But with a team like this that I've been working with for the last four years and especially with the focus and dedication of the teams on the ground, I promise you we'll bring home a gold medal."
Getting P3/P4 attached to the station's port truss will require one of the most ambitious flight plans ever put together for a shuttle mission.
Assuming an on-time launching, Atlantis will dock with the space station Tuesday around 12:40 p.m. Just two hours later, Burbank, operating the shuttle's robot arm, will lift the P3/P4 truss out of the cargo bay and hand it off to MacLean, who will be operating the station's more massive Canadarm 2. Canadarm 2 will be mounted atop a mobile transporter on the far end of the port truss.
"Normally, once we finish the rendezvous, we open the hatches, everybody says hello and we get down to doing some (equipment and supply) transfers and a few things like that," said lead shuttle flight director Paul Dye. "We have so much on this mission that on this day, we're going to do the rendezvous and then we're going to ... take the payload, the P3/P4 truss segment, out of the bay and hand it off to the station before the crew goes to bed.
"So while we are equalizing air pressure between the spacecraft and opening the hatches and getting things connected and shaking hands and greeting, we're going to have crew on the aft flight deck getting ready to pull the P3 out."
Because the 50-foot-long orbiter boom sensor system, or OBSS, will be in place along the right side of Atlantis' payload bay, Burbank will have about one inch of clearance as he unberths P3/P4. To get past the OBSS, he will have to move the arm in a complex sequence, being careful not to bang into anything along the way.
"We'll grapple the payload, we'll move it up, back a little bit, up a little bit more to where we're clear, then out to the side and then we have a large automated maneuver which will put it into what we call the handoff position so the station can go and grab that with the big arm," Dye said.
"This is a pretty significant activity by itself and putting it on rendezvous day makes this a pretty long and very interesting day. Once we have it held in the handoff position, the station arm will move in and grapple. Once they've got it, we'll release it with our arm and at that point, it becomes (the station's) piece of equipment."
MacLean will leave P3/P4 parked overnight on the left side of the shuttle just below the station's unfinished truss. Before the crew goes to bed, they will change the orientation of the shuttle-station complex, rolling 45 degrees to port. That will aim the left side of the truss down toward Earth and help keep the stowed solar array blankets warm.
The next day, MacLean will move P3/P4 up to the station's P1 truss (there is no P2 element). Once properly aligned, motorized bolts in P1 will be powered up to lock the new truss in place.
As soon as three of the four attachment bolts are engaged, Tanner and Piper will exit the station's Quest airlock and begin a complex spacewalk to make critical electrical connections required to power heaters and other systems necessary to keep the new arrays alive.
Electrical power to the U.S. section of the space station currently is provided by solar arrays mounted atop a short truss, known as Z1, that extends up in the zenith direction from the station's multi-hatch Unity module.
Those arrays, known as P6, will be moved down to the main solar array truss next year and attached to a short spacer, known as P5, that will be bolted to P4 during the next shuttle assembly mission in December.
To wire in the new P4 arrays, flight controllers in Houston will carefully power down the station's two P6 electrical channels, one at a time, so Tanner can hook up 13 umbilical cables between P1 and P3/P4.
"There are about a hundred pages of ground commanding that have to go on in order to get things powered down in the right order and get things switched over and powered back up again afterwards," station flight director John McCullough said in an interview. "It's one of the more tightly choreographed EVAs that we've done as far as ground and crew interaction."
The P4 solar arrays are packed up like venetian blinds in four large "blanket boxes." Tanner and Piper will prepare those boxes for deployment and start the process of readying the SARJ for operation.
The next day, MacLean and Burbank will carry out a second spacewalk to complete preparations for SARJ operation and solar array deploy. That night, flight controllers will send commands to extend the arrays one mast bay in a confidence test before the astronauts take over the next morning. First, they will extend each array to 49 percent and then, after letting the sun heat them up a bit, the rest of the way.
The stepwise approach is being taken because of problems encountered in December 2000 when the P6 array was deployed. When the first P6 wing unfurled, several solar cell panels stuck together, resulting in a jerky motion that caused a tension cable to unwind and jump from its spool.
The second P6 array was deployed in high-tension mode, which prevented additional problems. Engineers now believe the "stiction" was caused by subtle effects of atomic oxygen coating the arrays and low temperatures. For the P3/P4 deploy, the arrays will be extended in high-tension mode with enough solar heating to preclude similar problems.
Fully extended, the 38-foot-wide arrays will span 240 feet from tip to tip. Some 66,000 solar array cells will generate nearly 66 kilowatts of usable power. A dozen massive batteries will provide power when the station moves into Earth's shadow and ammonia lines inside accordion-like radiator panels extending 44 feet will shed the heat generated by the electrical circuits.
But the new arrays will not provide power to the station until the next shuttle mission in December when the left side of the P6 array is retracted. In its current position, the port wing of the P6 array is at right angles to the P4 wings, extending into the area where P4 eventually will rotate.
With the new arrays deployed, Tanner and Piper will stage a third spacewalk the following day to complete SARJ activation, to carry out critical repairs on the station's S-band antenna system and to install a thermal blanket around components of the lab's high-speed KU-band antenna.
For Jett, the number one concern for mission STS-115 is the timeline.
"I try to worry about the things we have control over," he told CBS News in an interview. "All the hardware issues, whether the SARJ is going to work right, I'll let somebody else worry about that. But the timeline is something we have control over and when you look at the first five days of this mission, we've never put a mission together with that many major activities in the first five days, Hubble or no Hubble. It's unprecedented and it's going to be really tough.
"The second thing I spend a little time (thinking about) is the unberth of P3/P4. The clearance is extremely tight. ... Dan is going to do a little maneuver while the payload is still coming out of the bay, he's going to slide it to port about two inches to give us a little bit of extra clearance on the (inspection) boom.
"When you have a big payload like that, you'd like to try to move it in one axis at a time when you're working with real tight clearances. So Dan's actually going to be moving it up and to the port side of the shuttle at the same time. How the payload actually responds to that, when he stops that sideways maneuver, will you get a little oscillation? Our clearance on the left side will be about an inch. So that's gotten our attention."
If all goes well, Atlantis will undock from the space station Sept. 4. The next day, the crew will carry out heat shield inspections to make sure Atlantis hasn't been hit by any orbital debris or micrometeoroids since they carried out a post-launch inspection on the second day of the mission.
Landing back at the Kennedy Space Center is targeted for a few minutes past noon on Sept. 7. Assuming the shuttle's external tank performed well and no major impact damage occurs, NASA managers will relax a post-Columbia requirement to launch in daylight, opening up more space station launch windows and clearing the way for a night launch of Discovery Dec. 14 on mission STS-116.
It all starts Sunday when Atlantis takes off on its first flight in four years to begin an assembly sequence that's been on hold since Columbia went down on Feb. 1, 2003.
"The restart of assembly, obviously, fulfills the first objective of the president's vision, that is, return the shuttle to flight and complete the space station," Jett said. "We have to do that as an agency and this mission marks the restart of the assembly sequence."
But Atlantis' flight, he said, "is just one of the assembly missions we have to get done. Every crew and every mission control team has to be on their game when we fly these assembly missions. We've got to do them right. We can handle some setbacks, we can deal with some problems but we have to perform these missions well and we have only a limited amount of time to do it. They're all important.
"If we do our jobs right, we'll get to 2010 and we'll retire the shuttle safely, we'll see it come to a wheels stopped not too far from here and we'll have a complete station. That's what we're really all looking forward to."
ANOTHER CLOSELY SCRUTINIZED LAUNCH
MacLean's first shuttle flight was delayed by the 1986 Challenger disaster and his second by the 2003 loss of Columbia. He believes NASA has addressed the major known risks of flying the shuttle.
"We had eight major known risks that came out of the Challenger accident and we have fixed those," he said in an interview with CBS News. "The brakes are better, we have nose wheel steering, we have a drag chute, we have better engines with the new turbopumps. We have a whole different abort boundary sequence going up the East Coast now with five Canadian sites. That abort sequence is so much safer than it was prior to Challenger. I was impressed with what NASA was able to do in two years and eight months after the Challenger accident with respect to improving the safety of the vehicle by an order of magnitude.
"After the Columbia accident, we had a problem that was plaguing us for a while and we haven't solved it yet. The foam is not understood. Do we understand the foam problem? Yes. Do we understand the interaction of the foam? No. Can we fix it? I don't think we can. But can we minimize it? Yes, we have. We have minimized that problem, foam will not bite us on future missions. We may have some issues with foam, but it won't bite us the way it did when Columbia happened.
"So I think we've minimized all known risks on the vehicle. I looked at it as seriously as anybody given that I'm flying on it. It's something that you really do need to look at because I wouldn't go if I thought it wasn't safe. I have decided, just like I did after Challenger, it's worth it. I'm looking very much forward to doing it."
That doesn't mean he turns a blind eye to the risks posed by riding on a space shuttle, regardless of post-Columbia safety upgrades and improvements.
"People ask, what's the hardest thing in spaceflight, the most difficult thing?" MacLean reflected in an interview. "It isn't walking out to the launch pad. It's saying goodbye to your kids, that's what's hard, and to your wife. That's very hard to do. It's something I wasn't prepared for on my first flight and I didn't realize until I had to do it that that was very difficult."
When Columbia returned to Earth on Feb. 1, 2003, no one knew the ship's left wing had suffered catastrophic impact damage during launch 16 days earlier. Long-range tracking cameras showed a chunk of foam debris from the shuttle's external tank breaking away from the tank's left bipod ramp 81.7 seconds after liftoff, but they did not show where the foam hit.
From the perspective of the only camera with a good view, the foam disappeared under the left wing followed by a shower of debris an instant later. Clearly, the foam hit the wing. But where? Engineers ultimately concluded it probably hit on the underside of the wing and, at most, damaged a few of the heat shield tiles in the area. No one believed the damage was catastrophic. But lacking good camera views, no one really knew.
As it turned out, the 1.67-pound chunk of foam hit the left wing's leading edge at a relative velocity of nearly 550 mph, blasting a 6- to 10-inch hole in the reinforced carbon carbon insulation. During re-entry, super-heated plasma burned its way inside, melting the left wing from the inside out and triggering a catastrophic structural failure.
NASA eliminated the bipod ramp foam that was the actual cause of Columbia's demise and made other improvements intended to minimize foam shedding in general. But when Discovery took off on the first post-Columbia mission in July 2005, engineers were surprised to see a large one-pound chunk of foam insulation fall away from a so-called protuberance air-load ramp on the shuttle's external fuel tank.
The manually applied foam ramps were in place to provide an aerodynamic barrier of sorts to smooth the flow of supersonic air over two pressurization lines and a long cable tray. After months of computer analysis and wind tunnel testing in the wake of Discovery's 2005 flight, engineers were able to prove the ramps were not needed, clearing the way for Discovery's launch July 4 with a tank that did not have any PAL ramps.
The largest foam buildups still in place on the tank are the ice-frost ramps. Shuttle program manager Wayne Hale said earlier this month engineers are working on two redesign options, one of which will fly on the first 2007 mission. But until then, Jett's crew and the crew of the planned December mission will have to rely on the old design.
Based on the performance of Discovery's tank last month, they can rest relatively easy. The tank performed well and no large pieces of foam fell off. But NASA managers want one more test flight before relaxing at least some of the post-Columbia safety constraints.
Like NASA's self-imposed requirement for two problem-free daylight launchings.
To reach the international space station, the shuttle must launch into the plane of the lab's orbit during periods when the angle between that plane and the sun provides acceptable temperatures. Those requirements, plus the need to launch in daylight and to ensure external tank separation in daylight for photo documentation, severely limit when a shuttle can fly.
For Atlantis, all of those conditions are met between Aug. 27 and Sept. 13. But the Russians are scheduled to launch the station's next full-time crew - Expedition 14 commander Mike Lopez-Alegria and cosmonaut Mikhail Tyurin - and space tourist Anousheh Ansari in September and flight rules require at least one full day between when a shuttle undocks and when a Soyuz arrives.
If the Russians delay their launch past Sept. 18, the station's returning crew - Expedition 13 commander Pavel Vinogradov, flight engineer Jeff Williams and X-Prize sponsor Ansari, would face a dead-of-night landing in Kazakhstan. The Russians are using new management for the Soyuz recovery and want to make sure landing occurs within a few hours of dawn at the worst.
As a result, Atlantis must get off the ground by Sept. 7 or the flight will be delayed to a short two-day window in late October. Only one lighted launch opportunity is available between then and February. Hoping for the best, NASA's launch team plans to make up to seven launch attempts between Aug. 27 and Sept. 7 if the weather or some other problem prevents an on-time takeoff.
As with Discovery's flight last month, NASA will utilize an upgraded tracking camera network at the Kennedy Space Center and Cape Canaveral Air Force Station to make sure any foam impact damage is seen as soon as possible.
The ability to quickly spot such damage, giving engineers time to assess the consequences and possible repair options, was a large part of Griffin's justification for proceeding with flight even though the tank still features ice-frost ramps that are considered an unacceptable risk.
At launch complex 39B, some 38 16mm cameras are mounted on the launch pad itself with three short-range camera sites around the pad perimeter featuring two 35mm cameras and one high definition TV camera each. Another 11 medium-range camera sites are positioned around the pad between one and six miles away, each one equipped with a 35mm camera and all but one equipped with an HDTV camera. Another 11 long-range camera sites are located between four and 40 miles of the pad. All long-range sites include 35mm cameras, two have 70mm cameras and 10 are equipped with HDTV.
From liftoff through the first 30 seconds of flight, objects an inch wide or larger can be seen. Between 30 seconds and one minute, the resolution drops to objects three inches in diameter or larger and from one minute to 90 seconds, it drops to objects eight inches or larger. Between 90 seconds and booster separation two minutes after liftoff, ground-based tracking cameras can detect objects 15 inches across and pinpoint an impact site to within five feet.
One WB-57 jet will be cruising 60,000 feet up to photograph the shuttle using infrared sensors and HDTV cameras attached to powerful 11-inch Celestron telescopes. The WB-57 will acquire most of its imagery in the minute leading up to solid-fuel booster separation.
Finally, a radar system is in place featuring one ground-based C-band and two ship-based Doppler X-band instruments to look for debris coming off the external tank.
For Atlantis' flight, eight cameras mounted on the shuttle, its tank and twin boosters will provide close-up views of the external tank and the orbiter's belly during ascent.
Another camera mounted high up on the external tank looking down on the underside of the space shuttle will beam back live television views throughout the eight-and-a-half-minute climb to orbit.
As with Discovery's flight last month, Atlantis is equipped with four other cameras, two near the top of each booster and two mounted near the back end of the powerful rockets. Each booster also carries a camera focused on a region of the tank known for losing small, popcorn-like pieces of foam.
Imagery from the six booster cams will be available after the spent rockets are recovered and towed back to Port Canaveral a few days after launch.
In addition, a digital camera mounted in a cavity where a propellant line enters the belly of the orbiter will photograph the tank as it separates in space.
As if all that wasn't enough, an X-band marine radar seven-tenths of a mile from the pad will be on the lookout for vultures and other large birds. During Discovery's launch in 2005, a large vulture struck the external tank a few seconds after liftoff, rammed by the shuttle at some 70 mph. If any large birds are seen prior to Atlantis' launch Sunday, the countdown can be halted briefly if necessary.
In short, if any impact damage occurs from any source, shuttle engineers expect to see it. NASA managers hope the radar systems, still somewhat experimental, eventually will provide enough resolution to permit acceptable debris coverage for night launches. But in the meantime, good lighting is required.
Once in orbit, Jett and company will take over the inspection work, photographing the external tank as it tumbles away using a digital still camera and a movie camera. Depending on what sort of motions, or "tip-off rates," are imparted at separation, lighting may be marginal.
Data collected by the wing leading edge impact sensors also will be downlinked to mission control for detailed analysis. Located on each wing's forward spar behind every reinforced carbon carbon panel, the 132 accelerometers will provide data telling flight controllers whether anything struck the leading edges during launch.
On the second day of the mission, the astronauts will spend six-and-a-half hours using Atlantis' robot arm and the 50-foot OBSS extension to inspect the wing leading edge panels and the shuttle's reinforced carbon carbon nose cap.
A laser sensor on the end of the boom is capable of spotting any wing leading edge damage that could pose a threat to the shuttle. The astronauts will start with the starboard, or right-side, wing leading edge, making six passes up and down the wing to cover all the angles. After scanning the nose cap, they will move on to the port wing and repeat the procedure.
A high-resolution camera is mounted on the end of the OBSS to take close-up photographs of any potential damage sites. No such "focused inspection" is planned, but if any sites of interest are identified, the camera is capable of resolving features as small as .08 inches across.
"That has been a major role for Canada, the inspection of the vehicle," MacLean said in a NASA interview. "The shuttle arm is basically going to pick up this 50-foot-long telephone pole that's going to act like a dental mirror, and then work under the wings of the shuttle and see if there's any damage.
"Dan Burbank and Chris Ferguson and myself are the three operators of the inspection system," MacLean said. "Initially Dan uses the arm, picks up the boom, and then we start the scanning. We rotate a little through our positions and it takes the entire day to scan the port wing and to scan the starboard wing and to look at the nose cap as well. It's not a pun, but it is a focused day in order to make sure that we did not sustain any damage through the launch sequence."
As it turns out, one of the most effective ways to look for signs of damage occurs during final approach to the space station. At a distance of about 600 feet directly below the lab complex, Jett will guide Atlantis through a slow end-over-end flip known as a rotational pitch maneuver, or RPM. The maneuver will take about nine minutes to complete - three quarters of a degree per second - allowing station commander Vinogradov and Williams to photograph the shuttle's belly using digital cameras equipped with 400mm and 800mm telephoto lenses.
It was during an identical flip during Discovery's flight last year that controllers spotted two so-called gap fillers protruding above the tile on the shuttle's belly, prompting an impromptu spacewalk repair later in the mission. Since then, thousands of gap fillers have been removed and replaced.
Good imagery, radar and impact sensor data form one leg of Griffin's three-pronged justification for flight. The other two components are the crew's ability to repair minor damage and, in a worst-case scenario, the capability of the space station to support a combined crew of nine until a rescue flight can be mounted.
It would not be easy. The Russian Elektron oxygen generator has a history of malfunctions, there is only one toilet on board and supplies would be tight. Worse, the only way down in a major emergency would be a single three-seat Soyuz capsule.
But NASA and the Russians have pre-positioned additional supplies for just such a contingency, including food, water and lithium hydroxide to scrub carbon dioxide from the air. Even if the Elektron failed the day Atlantis took off, the station has enough alternative oxygen generation capability to support the combined nine-member crew for about 76 days.
NASA managers are increasingly optimistic they will never have to invoke the "safe haven" option. Along with removing all large concentrations of foam on the external fuel tank, engineers have been working on techniques for repairing damage to a shuttle's heat shield tiles and even the critical wing leading edge panels.
Tests carried out during a spacewalk last month aboard Discovery show small cracks in the reinforced carbon carbon material may be repairable with a material known as NOAX. Two repaired cracks subjected to arc jet tests showed the material held up well under actual re-entry level temperatures.
"These first two samples ... have passed with flying colors, very intense re-entry profiles," Hale said. "So we are demonstrating good progress toward having good repair capability should we have damage to the thermal protection system."
That doesn't mean NASA will ever be able to formally certify a repair technique. Certification means a process has been subjected to enough tests to prove it will work under specified conditions.
"I doubt that we will ever have a certified TPS repair capability in the way that NASA likes to define certification," Hale said. "We're going to have some repair techniques, we're going to gain increasing confidence on the types of damage that they would be effective to repair, but I doubt that in the life of the shuttle program we will be able to achieve what we would normally call a certified capability."
For his part, Jett believes NASA has done the best it reasonably can to minimize the threat posed by falling foam insulation. He believes it's time for NASA to get on with space station assembly.
"Since the Columbia accident, the two missions since then have been focused a lot on the return to flight objectives, primarily fixing the external tank and some of the other things recommended by the CAIB (Columbia Accident Investigation Board)," Jett said in a NASA interview.
"Now those missions have been very valuable to station as well - logistically, making repairs for the station, adding a third crew member. But really, 115 is the return to the assembly sequence, and I think that's significant. We have a mandate to finish the station by 2010 and retire the shuttle. So we need to shift from the return-to-flight mode back to a more operational assembly sequence, where we're flying hopefully four to five times a year and, completing the assembly fairly quickly."
BUILDING AN OUTPOST IN SPACE
The international space station was born in President Ronald Reagan's 1984 State of the Union address. Reagan told the American public the station would cost $8 billion and be ready for operation by 1992, the 500th anniversary of Columbus's discovery of the new world.
It didn't quite work out that way. The $8 billion was misleading at best because it did not include shuttle transportation costs. Shifting requirements and concern in Congress led to numerous redesigns, culminating in the early 1990s with a Clinton administration decision to invite the Russians to participate in the program.
The Russians were building their own space station, Mir, but in the wake of the Soviet Union's collapse, the writing was on the wall: neither nation could afford to go it alone. The Clinton administration also saw a joint space station as a peaceful project for Russian space scientists. And so, after using Mir to work out flight control procedures, Russia launched the first international space station module in 1998. The first U.S. module followed suit three weeks later and construction began in earnest.
Then came the Columbia disaster, stopping assembly in its tracks and forcing NASA and the Russians to drastically scale back station operations. Crew size dropped from three to two because without the shuttle, there was no way to launch enough water and other supplies to support a three-person crew.
While NASA was struggling to recover from the Columbia accident, the Bush administration was rethinking the nation's space policy. Based in part on recommendations from the Columbia Accident Investigation Board, Bush unveiled a new space initiative in January, 2004, ordering NASA to complete the station and retire the shuttle by 2010 and to develop a new manned spacecraft to service the station and eventually to carry astronauts back to the moon.
When Columbia broke apart on the way back to Earth, Jett and his crewmates already were training for their mission. NASA envisioned nearly 30 space shuttle flights to build, outfit and supply the international space station before assembly would be declared complete.
Suddenly faced with the Bush administration's 2010 deadline, NASA pared the assembly sequence to the bone, chopping about 10 missions and leaving a manifest with just 17 flights - 18 counting a yet-to-be-approved mission to service the Hubble Space Telescope - and two contingency missions.
Along with downsizing the station, the lab's scientific justification has changed as well. The project originally was sold on the research that would be conducted aboard the outpost, a tough sell given the enormous cost of the project: More than $100 billion through the first 10 years of operation.
The goal now is to finish the station, attach European and Japanese research modules as part of long-standing commitments and use the outpost to test hardware needed for the eventual exploration of the moon and Mars and to learn more about how the space environment affects human physiology.
"From my perspective as an engineer, which I admit is biased, the main purpose of the station is to learn how to live and work in space," Griffin told CBS News in a recent interview. "Whenever humans are ready to go to Mars, we're going to need an amount of hardware in space about the size of the space station when it's done. That's how much we need to go to Mars. And hopefully we will have learned so much from how we've assembled station that we'll do a great job on it. It won't take us 20 years to put together the hardware to go to Mars because we'll have learned."
That's not to say Griffin would have built this particular space station if he'd been involved in the original decisions.
"People should understand, from where we are at this point in time, the right thing to do is to fly out the shuttle to retirement and use it to assemble the station. OK? Because otherwise, we're not taking advantage of the investment we've made," he said. "Now, what is true is that I think we did things in the wrong order. The right approach to running the nation's space program would, in my mind, never have been to abandon going to the moon as we did in the early 70s. I've characterized that over and over again as one of the many unfortunate decisions to come out of the Nixon administration.
"That said, that decision was made and other consequences followed from it, one of which is we built the shuttle and declared the space station to be the major project we would use it for. And we've been working on the station now for 22 years.
"Now if you ask me, when people say I would never do this, they've got it wrong. If you want to go to Mars, the building of a space station is an important step along that way. It's possible to go to Mars without having built a space station, but I think in preparing for a voyage to Mars, a space station is a step along the way and I would have done that. I would not have done it in this way, I would not have done it in 25,000- or 30,000-pound chunks at a time over dozens of shuttle flights. I would have done it more like we did Skylab, where we put up 200,000 pounds at a time.
"As an engineer, the way we went about it, because of the order in which we made our decisions, offends me," Griffin said. "I'm offended as a technical person, because I don't like the way in which we did it. But no one will ever get me to say that a space station is not a valuable step along the road to Mars. If I've not been clear with these comments, ask me again and I'll clarify. Because what Mike thinks is often misreported by those who don't even bother to ask me the question."
The international space station currently consists of six pressurized modules. At the back end of the outpost is the Russian Zvezda command module featuring two solar arrays and an aft docking port that can accommodate Progress supply ships or Soyuz capsules. An airlock module called Pirs is attached to a downward-facing port on Zvezda's front end. The module forward port is attached to the Russian Zarya module, a supply and propulsion module equipped with its own pair of solar arrays.
Zarya's front end is bolted to a pressurized mating adapter that, in turn, is attached to NASA's Unity module, a multi-hatch node with six ports. Its starboard port connects to the U.S. Quest airlock module while its upper zenith port accommodates the Z1 truss and the P6 solar arrays. Unity's downward facing port is used by cargo modules brought up by the shuttle and its port hatch is home to another pressurized mating adapter that will be relocated later in the assembly sequence.
Unity's forward port is attached to the Destiny laboratory module. On the forward end of Destiny is another pressurized mating adapter used as a docking port by visiting space shuttles. On top of the lab module is the station's main solar array truss, which is mounted at right angles to the long axis formed by the pressurized modules.
The S0 truss sits in the middle atop the lab, flanked by the S1 and P1 truss elements. S1, S0 and P1 house a variety of electrical components and the station's main ammonia cooling system, including huge articulating radiator panels.
The lab module also is home to the station's Canadarm 2 robot arm, a marvel of engineering that is capable of moving, end over end like an earthworm, from work site to work site on the solar array truss.
During Atlantis' flight, the P3/P4 truss elements and solar array panels will be attached to the left side of the truss. In December, an even more complicated flight is planned to attach the P5 spacer truss, activate the space station's main ammonia cooling system, retract the port wing of the P6 solar array and tie the new P4 arrays into the lab's electrical system. Hill said STS-116 will be even more challenging than Atlantis' mission.
"Getting P3/P4 installed and activated, both those solar arrays out, getting that SARJ checked out and turning, which is something we've never done in orbit, those are big steps," Hill said. "All this reconfiguration we have to do on 116, those are big steps.
"That flight right there and that choreography is something that when we first came up with this sequence in 1994, we all sat back and said wow, how are we going to figure this one out? Today, the folks who have been leading that effort feel pretty good they've got their arms around it but they're also really worried and keeping their fingers crossed that everything goes well."
With P5 installed and the port wing of P6 retracted, another shuttle crew will visit the station in February to retract the starboard P6 array and to attach the S3/S4 truss and solar array segments on the right side of the station's main truss. The S5 segment will be carried up next June along with a power transfer system that will let space shuttles plug into the station's electrical system to extend their stays at the lab.
Next August, the P6 arrays will be repositioned and extended on the port side of the truss and a new multi-hatch module - Node 2 - will be delivered. Between shuttle flights, the station crew will reposition Node 2, using the Canadarm 2 to move it to the front of the U.S. Destiny laboratory module to provide the docking ports needed by European and Japanese research modules.
"Moving P6, retracting those solar arrays and then unplugging that truss segment and moving it outboard, that right there is the single most complicated and hairiest thing we're doing in building the station," Hill said. "We've known that from the get go.
"You've got to reach out and install it without bonking into either one of the two P4 solar arrays while you're doing it, you've got to get it done on time because that guy's getting cold from the point you turn it off and unplug it. You need to get it attached and reconnected so you can fire up that hardware. If the solar arrays go back in the can, the rest of it ought to go pretty lickety split."
Whether the P6 arrays will, in fact, roll up as required remains to be seen.
"The guys who built it, they designed it to retract and they expect it to retract," Hill said. "But for a solar array that's been hanging out in the breeze, where if we took a (space debris) strike and dinged one of those structural elements, there's a real good chance that we're not going to be able to fully retract those arrays. We'll see what we get."
Next September, the European Space Agency's Columbus research module will go up, followed over the next three flights by components making up Japan's Kibo research modules and external platforms. In June of 2008, the station's fourth and final set of solar arrays will be delivered. The last major module, Node 3, is scheduled for attachment in January 2010.
By the end of assembly, the international space station will weigh nearly 1 million pounds and have the pressurized volume of two 747 jumbo jets. Its finished solar array truss will stretch the length of a football field and its eight huge solar array wings will generate some 75 kilowatts of power, enough to supply 55 average homes. Crew size will be bumped up to six astronauts and cosmonauts by early 2009 with Russian Soyuz spacecraft and NASA's new Orion capsules providing crew ferry and lifeboat capability after the shuttle is retired.
"The international space station originally was conceived as a world class research facility," said Mike Suffredini, space station program manager at the Johnson Space Center. "It will continue to provide that capability for research that you can do in space that can open our eyes to problems on the ground. Today, we have a number of plans to up the research capability, the research suite of hardware, during the assembly process such that we will be able to utilize it.
"However, what we look to ISS for as well is the exploration," he said. "We will use it to test systems that we plan to utilize on the moon and Mars, it's going to be really critical that we build highly reliable systems. The best place to test systems, particularly that have to operate in a zero-gravity environment, would be on the space station.
"In addition to that, we need to learn to operate in the limited logistics fashion. We've learned quite a bit over the last three years. The third, which is critical as well, is studying human physiology and the psychology of long-term stays in space."
Suffredini said the station also would serve as a proving ground for the new Orion crew exploration vehicles that eventually will replace the space shuttle. As it now stands, Orion is not expected to begin carrying astronauts until the 2014 time frame. During the gap between the end of shuttle operations in 2010 and the advent of Orion, NASA will rely on commercial agreements with the Russian space agency to launch U.S. astronauts on Soyuz spacecraft.
While larger and more capable than the venerable Soyuz, the new Orion spacecraft will not be able to match the cargo delivery capabilities of the space shuttle. Some critics have questioned whether NASA can keep the station going without the ability to launch large spares when components break down, but Griffin said that will not be a major problem.
"With the Ares 1 launch vehicle and the (Orion) CEV, we're deliberately building in a substantial amount of flexibility," Griffin told CBS News. "The Ares 1 can be launched in an unmanned mode, it can be launched with the service module and not with the command module and can be used to take up unpressurized cargo in that fashion to the station, including (gyroscopes) and other (large) things.
"So we're designing the system to be modular and adaptable and flexible so it can do much, not all, but much of what the shuttle does today," Griffin said. "The shuttle has enormous capabilities, not all of which we will be able to replicate in the CEV system. But we're going to capture a good deal of it and we can, we absolutely can use the CEV and the Ares 1 launch vehicle to sustain the space station."
BACK-TO-BACK SPACEWALKS NEEDED TO HOOK UP NEW ARRAYS
Atlantis will rocket into orbit using a so-called "high-Q" ascent profile that puts slightly greater aerodynamic stress on the spacecraft. "Q" is the letter symbolizing aerodynamic pressure in a variety of calculations.
For Discovery's flight last month, flight controllers approved a low-Q ascent, one the lofted the ship's trajectory slightly to get it out of the thick lower atmosphere faster. The idea was to minimize the stress on the external tank's foam insulation.
But that is not an option for Atlantis because of the heavy weight of the P3/P4 payload.
"As far as we're concerned, it's not an issue," Jett said. "If you look at the difference between a low-Q ascent and high Q, for us the main differences are when we pick up our different abort boundaries. So from a crew perspective, high Q gives us more abort options during the ascent.
"The program has looked at the margins on the tank, they're very comfortable with the margins both structurally and with the foam performance. So we believe it was the right decision to go high Q on 115. With our heavy payload, low Q would have been very, very difficult for us to do."
The day after reaching orbit, the Atlantis astronauts will check out a pair of spacesuits, ready equipment for transfer to the space station and carry out the flight-day-two wing leading edge and nose cap inspections that are now a standard part of every shuttle flight.
Jett will fly a standard rendezvous profile, approaching the lab complex from behind and below. The terminal phase of the rendezvous procedure begins about three hours before docking with the shuttle trailing the station by about 9.2 miles.
On final approach, at a distance of about 600 feet directly below the station, with Atlantis nose facing forward and its open payload bay facing the station, Jett will carry out the slow 360-degree rotational pitch maneuver, or RPM, that will point the belly of the shuttle at the station.
As the shuttle's underside rotates into view, Expedition 13 commander Vinogradov and flight engineer Williams will photograph Atlantis' belly with handheld digital cameras equipped with 400mm and 800mm lenses. The former has a resolution of three inches while the latter has a resolution of one inch.
Imagery from the station will be downlinked to Houston for detailed analysis.
"The RPM maneuver, or rendezvous pitch maneuver, is actually very visually dramatic," Jett said in a NASA interview. "But from a flying standpoint, it's not really any more difficult than any other type flying we do for rendezvous. The real significance of the RPM is that it allows the station crew to take photos of the underbelly tile areas of the orbiter, which we don't inspect on flight day two. On flight day two, we're looking primarily at leading edge of the wing so this is a whole other area of the thermal protection system, which allows the folks on the ground to analyze for any damage.
"If for some reason we can't do the RPM, it's a significant impact to our mission because we still have to, at some point, go under there and look at the tile. The RPM is a very, very efficient way for us to do a little flip maneuver, as we approach the station and allow the station crew members to use an 800mm lens to photograph all the tile and send it down to the ground and let them analyze it. So it's a real important maneuver."
After completing the pitch-around, Jett will position Atlantis about 400 feet directly ahead of the space station with the shuttle's nose facing deep space and its cargo bay facing the lab complex. He then will guide the spacecraft to a docking with a pressurized mating adaptor attached to the front of the Destiny laboratory module. Assuming an on-time launch, docking is expected around 12:40 p.m. on Aug. 29.
After leak checks, Vinogradov, Williams and European Space Agency astronaut Thomas Reiter, ferried to the station aboard Discovery last month, will welcome the Atlantis crew aboard the station and provide a safety briefing before all nine astronauts get down to work.
"What we've elected to do ... is to get right into the payload operations shortly after docking. So about two hours after we're together, hard-mated and the hatches are open, Dan and I are going to extract the payload from the payload bay. Once again, this payload is huge, it occupies the entire payload bay and weighs about 36,000 pounds, so it's no small operation. There are some areas where the clearances get rather tight."
Burbank, operating the arm, will have just one inch of clearance between P3/P4 and the OBSS heat shield inspection boom mounted along the right wall of the payload bay. As he is lifting the payload straight up from its perch in the payload bay, Burbank will have to jog it slightly to the left to avoid the OBSS. It is a delicate procedure because of the payload's inertia and the need to avoid any overshoots that could cause it to hit anything.
Assuming all goes well, Burbank will position P3/P4 over the left wing of the shuttle. At that point, MacLean, operating the space station's more massive arm from inside the Destiny laboratory module, will grapple P3/P4 in a handoff maneuver and Burbank will release the truss with the shuttle's arm.
"I'm out on work site 7, which is as far as you can go on the space station with the station arm, or Canadarm 2," MacLean said in an interview. "I'm prepositioned so I can accept the handoff. Dan will get it into position and then I'll go in for the handshake when both arms are holding it. Dan will let go and we'll park there over night."
MacLean said the handoff will mark a proud moment for Canada, which provided both robot arms and the Space Vision System that will be used later to precisely position P3/P4 for attachment to the station's truss.
"Don't be surprised if you hear a call out on the 'great Canadian handshake,'" MacLean joked at a news conference. "But we are handshaking with a payload that is impressive, very high tech, that's going to carry us forward to having the best orbiting laboratory in the world."
Pulling P3/P4 from the cargo bay starts a 35-hour timer. That's how long the crew has to get the payload attached to the P1 truss and wired into the electrical system to power critical heaters. But the 13 umbilicals needed to route power and data to and from the new truss element will not be hooked up until the next day during a spacewalk by Tanner and Piper.
Instead, P3/P4 will be left hanging out over the left wing of the shuttle, safely attached to the station's robot arm, while the astronauts wind down from a very busy third day in space.
Tanner and Piper will spend the night sealed up in the Quest airlock module as part of a new "campout" procedure. The airlock's pressure will be lowered from 14.2 pounds per square inch to 10.2 psi to help the spacewalkers purge nitrogen from their blood and prevent the bends when working in their 5-psi spacesuits.
Flight controllers in Houston plan to roll the station about 45 degrees to port, dipping the port side of the solar array truss down toward Earth, to improve the thermal environment. The next morning, after a "hygiene break," Tanner and Piper will begin donning their spacesuits, assisted by Jett. MacLean, meanwhile, will return to the Destiny module, take control of Canadarm 2 and move P3/P4 up to a pre-install position just a few inches from P1.
"I'll maneuver the P3/P4 truss around up to the P1 truss, an operation that will take about 45 minutes, to the preinstall position nine centimeters away from the center of P1," MacLean said. "During that time, we have to do this attitude roll. It's tied to the arm operation because once we get to that position, it's a thermally very hot place and that's the best orientation to minimize that thermal case. Then you have to wait for the rates to damp out, that takes about 30 minutes plus or minus five or 10 minute probably, then we move in for the final install using the Canadian Space Vision System, which gives me the guidance data."
The Space Vision System uses television cameras and powerful software to measure the precise locations of large black dots attached to the truss elements. The SVS software computes the relative positions of the dots to give MacLean very precise distance and orientation information. Temperature effects can cause distortions of up to five inches, MacLean said, and misalignments of 1 to 2 degrees. The SVS will help compensate for any such effects.
"It'll take about an hour to get to the pre-install position there, and then we have to wait for an attitude change that we need in order to have the P3/P4 Truss at a thermally viable position," MacLean said. "And then we install. Fergy will come over and back me up with the Space Vision System and he will basically provide that data to me, and then using that data I will guide the P3/P4 truss in to the P1 Truss. And that'll be it. A good day."
The actual attachment is automatic. Once P1 and P3 are in close proximity, four motorized bolts on P1 will drive into attachment fittings on P3, firmly locking the two truss elements together. Three of four bolts must engage to call the operation a success.
At that point, Tanner and Piper, now suited up in the Quest airlock, will float out into space and begin the first of two back-to-back spacewalks to hook up and activate P3/P4.
"Once three of four of those bolts are mated, we'll go ahead and send the crew EVA and perform the activities that we need to do to make the element survivable," McCullough said. "All the power connections, the 13 umbilicals that need to be mated and all the activities to get ready for solar array deploy start on EVA-1. The power hookups all are completed by the end of EVA 1 and the element is completely survivable."
TWO SPACEWALKS TO CONNECT NEW ARRAYS
To get to the P1-P3/P4 worksite, Tanner and Piper will first exit the Quest airlock, using 55-foot-long safety tethers. Crossing over a spur to the S0 truss atop the Destiny laboratory module, the spacewalkers will move across the forward face of the truss to the port side and, reaching the end of their safety lines, hook up to a different 55-foot tether. Once at the P1-P3 interface, they will swap tethers again, switching to 85-foot safety lines.
A key aspect of the spacewalk is the tight choreography between flight controllers, Tanner and Piper as the ground powers down one channel of the station's electrical system at a time to permit the astronauts to safely plug in the big umbilical cables that will route power and data to and from P3/P4.
"The ground and the crew are very highly choreographed," McCullough said. "The ground has about 100 pages of ground procedures to execute in order to power down and safe connections for the EV crew to mate the 13 umbilicals. They're done on two different channels, so we have to power down one channel first, give them a go to hook up those umbilicals, then they give us a go and we power that channel back up again. We have to complete that before we can take down the next channel so we can maintain connectivity and power to the space station.
"It takes about an hour and a half between the two sets of umbilicals and when that's complete, the second set of umbilicals will be given a go and they'll do that. In between that time, there are other activities for the crew to do to get prepared for solar array deploy on flight day six."
For astronauts in the Destiny lab module, McCullough said in an interview, "a segment of the lights are going to go out that aren't on that channel. You want to be on the cooling loop system that's supplied by the other channel, so we switch over to that. You want to make sure your air circulation system is powered. ... We want to make sure we're switched over to the other side as much as possible."
In one case, he said, the astronauts in the lab will connect a jumper cable to keep avionics rack 2 going, which houses critical command and control computers that otherwise would get shut down during the P3/P4 powerup/powerdown cycle.
Along with hooking up the umbilicals, Tanner and Piper will remove a variety of launch locks and restraints to prepare the solar arrays for deployment later in the mission and begin the process of preparing the massive SARJ for operation.
"The solar alpha rotary joint is locked in place for launch," McCullough said. "It has 16 launch locks and a lot of braces that need to be installed to support rotation and we can't deploy the arrays until all of those things are completed."
Tanner's call sign is EV-1 and he will wear a spacesuit with solid red stripes around the legs. Piper, wearing a suit with no markings, is EV-2.
"While he's doing that, I'm starting to remove the launch locks on the solar array blanket boxes. The solar arrays are folded up into what we call blanket boxes. The blanket boxes are attached to a mast canister, which is attached to the four-bar linkage, which is attached to the P4 structure. In order to get that all to fit inside the shuttle bay and also have it be safe for the vibrations of launch there are a number of launch locks and bolts that just hold it all together.
"On EVA 1, I go out and start removing these bolts. The blanket boxes, instead of being out like you see them in all the pictures with the solar arrays deployed, are folded up together. They have big bolts that hold them together so I go out and I start removing all the bolts, first on the aft side and then I go to the forward side. Meanwhile, Joe's done with the umbilicals. He comes out and gets one of the solar arrays ... swings the four-bar out and then he climbs out onto the very end of the mast canister and swings the two blanket boxes out.
"While he's doing that, I'm out on the forward one, and I do the same thing. Now the blanket boxes are pretty much ready for the ground to start commanding them as far as unlatching them and making sure that all the pins that hold them in are all deploy. That gets that ready for the solar array deploys. We're not quite ready to deploy the arrays yet because, in order to get the P3/P4 to fit inside the shuttle bay, we have to have the alpha joint rotated 180 degrees. In order to rotate it back to the zero position, there are two drive mechanisms that needed to be deployed, the DLAs (drive lock assemblies). We start working on those so that they can command the SARJ. That's pretty much what EVA 1 is.
Tanner, his feet anchored in a foot restraint, will mate the first six umbilical cables working at the lower of two cable trays on P3. Piper, meanwhile, will be preparing the solar array wings for deployment, working from a foot restraint on P4 to access two sets of launch restraints, one inboard and one outboard, holding the blanket boxes in place.
Tanner will assist once the first six umbilicals are connected, releasing two restraints securing one of two beta gimbal assemblies. The BGAs are used to control the pitch of the array wings once they are deployed. After the restraints are released, the blanket boxes and the canisters holding the telescoping masts that will extend the array blankets will be rolled into their deploy positions by manually pushing open the four-bar linkages.
After stowing a massive keel pin that helped hold P3/P4 in place in the shuttle's cargo bay, Tanner will move to the mast canisters and rotate the 4A blanket boxes into position, swinging them through an arc of 90 degrees and locking them in place with a strut to hold them in position. Piper will rotate the 2A blanket boxes into place and release the restraints on the other BGA.
Once both sets of blanket boxes are extended in the deploy position, Tanner and Piper will release latches allowing the mast canisters to open. Tanner then will move up to the top of P4 to mate seven umbilical cables while Piper removes thermal covers on the SARJ and repositions one of the two drive lock assembly motors so its gears engage. She also will engage four "stiffeners" needed to provide additional structural support.
With the final set of electrical cables in place, Tanner will make his way up the Z1 truss atop the Unity module to remove a circuit interrupt device, or CID, as a get-ahead task for the next assembly mission. The CIDs act as circuit breakers in the station's electrical system. With CID-6 ion hand, Tanner will float back down the S0 truss and remove CID-8.
After temporarily stowing the two CIDs, Tanner will rejoin Piper and reposition the other DLA to engage its gears. The two DLAs are redundant and either one can drive the rotary joint and the deployed solar arrays.
Before returning to the airlock, Tanner and Piper will remove thermal shrouds around electrical components on the SARJ that are no longer needed.
"The big challenge about that EVA is timing," Tanner told CBS News. "We have to go through our tasks fairly expeditiously, I've got to get that lower tray connected as quickly as I can because that starts a clock on the ground with that 100 pages John McCullough was talking about. They've got to execute many power ups and start talking to the boxes."
Tanner was a good choice for STS-115. He and Jett flew together on an earlier station assembly mission to attach the P6 solar arrays atop the Z1 truss.
"Deploying the arrays, we've done it before, we know how that should go. I think there's going to be a little bit of a problem on the four bar deploy. On (assembly mission) 4A, we had a problem of them not wanting to go at all and Carlos (Noriega) and I had to push pretty hard just to get them to move and even brought out a special tool to pull them as far as we could. And even with that, two of the latches when we left were not engaged.
"I'm convinced we're not going to have that problem. It's not going to go too fast, it's going to go about two thirds of the way to full deployment but this time the finish will be as easy as pushing it the last little bit. So expect that to happen, I'm not worried about it."
With spacewalk No. 1 complete, Burbank and MacLean will spend the night inside Quest to prepare their bodies for a second spacewalk the next day. The objectives of the second excursion are to release 16 launch locks and six launch restraints to free the SARJ ring mechanism for rotation. Burbank and MacLean also will complete the installation of stiffeners to provide the necessary structural rigidity.
"Steve and I are going to spend the bulk of EVA 2 removing the whole series of these 16 plus six launch locks and launch restraints," Burbank said in a NASA interview. "We're going to spend most of our time right in the middle section of the P3/P4 truss driving a lot of bolts with a lot of power tools. After all that's done, we've removed all this hardware that's kept the P3 and P4 Trusses properly oriented for launch, we're going to deploy the SARJ braces, the solar alpha rotary joint braces, a series reinforcement structures that will help to stabilize that, that alpha rotary joint on both sides. So we'll spend a lot of time doing that.
"Then, time permitting, we'll be able to do some get-aheads, some of the work we're planning on doing on EVA 3. But EVA 2's kind of different. We're going out with a different kind of a CO2 scrubber in the (spacesuits) that allow us to go a little bit longer than planned if necessary. ... We've got a fairly ambitious suite of activities set up for EVA 1, and hopefully Joe and Heide will be able to get all that done, and then we've got a little bit of money in the bank on EVA 2 to go a little long if we have some problem with the hardware, because we'd really like to not have to spend another day before we deploy the solar wings here."
Burbank and MacLean will use the same tether protocol to reach the P3/P4 worksite on the left end of the truss. Once in place, they will start removing the 16 launch locks, a multi-step procedure that requires them to first release an inboard clamp; remove and temporarily stow a thermal cover; remove four bolts from the launch lock; and reinstall the thermal cover.
Once that work is done and the bolts are safely stowed in a transfer bag, the spacewalkers will remove six outboard launch restraints and install the brace beams needed to stiffen the inboard side of the SARJ interface.
"Dan and I spend a lot of time around that solar array rotary joint, making sure that it's ready so that that joint can move later on during the mission," MacLean said. "So we're removing all the launch locks associated with that, and that takes us a while because it was very important to minimize the vibration of that area during launch and we have several launch locks to take off. In addition, we will stiffen up the truss. ... Here we are, construction engineers, where we'll basically remove a brace and then bring it over and then reattach it, and that stiffens up the torsional mode of the truss. We do something similar on the, on the P4 side.
"We have some AJIS (Alpha Joint Interface Structure) struts that if Joe and Heide haven't got them done the day before we will do the AJIS struts on the P4 side, which again stiffen up the torsional mode of the P4 side."
THE STATION SPREADS ITS WINGS
When completed, the international space station will feature a huge solar array truss stretching more than 300 feet from tip to tip. Two huge solar arrays on each end of the truss will track the sun as the station circles the globe, rotating and changing pitch as required to maximize electrical generation.
Finishing the main truss and wiring in the new arrays is a major element of near-term station assembly missions.
One set of arrays, P6, is already attached to the station, providing power for the U.S. segment of the outpost. It is attached to the Z1 truss that extends upward from the Unity module at right angles to the main solar array truss. It will be moved next year to its final position next to the P4 arrays being attached by Atlantis' crew.
Designed by Boeing, the P4 truss features two motor-driven telescoping masts that will pull out a pair huge solar array wings measuring 240 feet from tip to tip when fully unfurled. For launch, the arrays are folded like venetian blinds in blanket boxes measuring 15 feet long but just 20 inches thick.
The P3 truss was delivered to the Kennedy Space Center in November 1999. P4 followed suit in July 2000. The solar array blankets have not been unfolded since they were originally stowed for launch.
Prior to Columbia's launch in January 2003, the arrays were certified to operate and deploy normally when stowed for up to 45 months. Because of the extended downtime after the Columbia accident, one of the blanket boxes on P4 was removed and shipped to California for deployment tests. A replacement blanket was installed aboard P4.
As it turned out, the deployment tests went well and the blanket, which had been stowed 39 months at that point, worked normally. As a result, the certification age limit was boosted to 82 months. At launch, the P4 blankets will have been stowed for 67 and 73 months respectively.
One other consequence of the Columbia recovery and subsequent launch delays was a decision to replace all 12 batteries in P4. The 372-pound batteries were swapped out in March and August of 2005.
The solar array wings were designed by Lockheed Martin. They weigh more than 2,400 pounds and feature some 33,000 solar cells per blanket. They are designed to produce more power than the station actually needs to compensate for normal degradation as the outpost ages. The blankets must face the sun directly for maximum electrical generation and two mechanisms are in place to do just that. The wings can be rotated about their long axis by beta gimbal joints, much like the pitch of an airplane propeller can be adjusted. The SARJ rotates the arrays through 360 degrees like a waterwheel.
The P4 integrated equipment assembly, or IEA, is a cube measuring 16 feet on a side and weighing nearly 17,000 pounds. It includes direct current converters, 12 batteries, battery chargers, control computers and an ammonia cooling system to keep the electronic gear at the proper temperature. A single set of folding radiator panels will extend 44 feet when fully deployed.
Most of the work to ready the new P4 arrays for extension "is done by the flight control team," Jett said. "The EVA crew does the physical work, in terms of, positioning the arrays and releasing all the bolts and the launch restraints. But then the preparation to actually make the deployment happen, all the activation sequence and the activation of the rotary joint, is all performed by the ground team.
"When we wake up on flight day six, if everything goes well the ground is going to be ready to go. We position a few cameras so we can monitor the deployment and then we go to the computer and command the arrays to deploy. Now, hopefully, everything will go very smoothly and the problem that we had on 97 we think has been solved. Hopefully, everything will go smooth and we'll get the arrays out in a couple of orbits.
The P4 arrays are identical to P6, which was attached to the space station during shuttle mission STS-97 in December 2000. When the first blanket was deployed, engineers were surprised to see several of the blanket panels had stuck together. When they jerked free, a tensioning cable jumped its guides and required repairs on a subsequent spacewalk. For the second array's deployment, the crew let the sun warm up the array and deployed it in a so-called high-tension mode. That technique worked, and the array unfurled without incident.
For the P4 deploy, flight controllers will extend a single bay of each mast - a few feet worth - while the Atlantis astronauts sleep. The crew then will extend the 4A mast to a distance of 49 percent, wait a half hour or so for additional solar heating, and then the rest of the way to full extension. They will repeat that process for the 2A mast.
"We're not too terribly concerned about stiction on the deploy," Tanner said. "We know it might happen in certain panels. The team went hard to work after STS-97 to figure out the mechanism of stiction and what we can do to reduce it. They came up with a good operational plan to nominally deploy.
"Now if for some reason one or two panels sticks after all that, then we can go out EVA, it would be on EVA 3, and actually manually peel the panels apart for the first 40 inches or so and doing a nominal deploy after that. All of our tests say they will peel open very easily. So we're not too terribly concerned about that."
"When we wake up in the morning I will be the only one over on the shuttle, and I'm going to be providing the station with views as the solar array wings are deployed. The balance of the shuttle crew will be on the station in various capacities: Brent will be actually unfurling of the mast canister, which will pull the solar arrays from their blanket boxes. ... I'd like to think we have (the stiction) problems circumvented."
Suffredini said experience gained during the STS-97 mission in 2000 should result in a smooth deploy.
"The good news is we've done it twice before," Suffredini said. "The first time we deployed one of these arrays, we learned about a stiction issue that existed. After quite a bit of work during that mission, we deployed the second array in a little bit different technique, which allowed us to be successful. We learned a lot about techniques to get these arrays out without having the tension wire come loose, which is what happened when we tried to deploy the first one. It turns out after a lot of work ... we figured out a fix to go back in there to put it back in its original condition. And of course, the arrays have been fine ever since.
Using an engineering model, "we did quite a bit of testing on this stiction issue and how these arrays can stick together based on the silicon bead that's on the arrays and then we compress them for long periods of time before they go fly. And that was basically the cause of the problem. Over a long period of time this silicon would tend to attach itself to the back part of the array. And so we've done a number of things, largely operational changes but also on how we dealt with the arrays."
While the arrays were compressed for shipment to Florida, that pressure was relaxed until shortly before final preparations.
"Probably the largest changes were operational," Suffredini said. "We will partially deploy the array about one bay's worth and we'll let it warm up and sort of expand a little bit. Then the actual deploy process a little bit later will have us deploy the array halfway and then you'll see us sit for about 30 minutes as we warm it up and then we'll go the rest of the way.
"In addition to that, we're using what we call a high-tension mode. Instead of leaving the lower part of the array free to move up and down as the array gets deployed, we learned we need to hold it down against the bottom of the blanket box. So the new technique holds it down and then this particular deploy lets the heat warm things up, to allow the silicon to free itself, is the process we'll use to deploy. I have a lot of confidence in the deployment of the arrays."
The new solar arrays will not be rotated on the SARJ because of interference with the port wing of the P6 array and they will not provide any power to the space station until reconfigurations during the next shuttle mission in December.
With the arrays deployed, the astronauts will move the Canadarm 2 space crane from the end of the truss back to the Destiny lab module. Some of the crew members will participate in media interviews while the rest gear up for a third spacewalk the next day by Tanner and Piper.
A FINAL SPACEWALK TO WRAP UP ARRAY WORK AND MAKE NEEDED REPAIRS
Tanner and Piper will spend a final night in the Quest airlock module prior to a third and final spacewalk on flight day seven (Sept. 2). The goals of the excursion are to wrap up final work to ready P3/P4 for operation, to repair the space station's S-band antenna system, to install a thermal blanket around electronics used by the station's high-speed KU-band antenna system and to retrieve a space exposure experiment.
The astronauts also will stow additional keel pins and other items to clear the path of the mobile transporter, which creeps along rails along the front side of the main solar array truss. The mobile transporter can lock itself down at various work sites to provide a stable work platform for Canadarm 2. With the addition of P3/P4, a new work site - WS-8 - will be available to permit the attachment of the P5 spacer truss in December.
If Burbank and MacLean are unable to complete installation of all the stiffener beams, "then we can do that on EVA 3 as well," Tanner said. "On P4 we have two activities. One to prepare the radiator for deploy, and then loosen some bolts on an MMOD (micrometeoroid orbital debris) cover. That's kind of a get-ahead, but we'll probably do that as well, and then relocate some foot restraints for 12A.1."
Tanner and Piper also will test an infrared camera under development as a diagnostic tool that could help future crews spot damage to the shuttle's wing leading edge panels.
"If everything that we have planned right now ends up on the plate for EVA 3, it'll take two-and-a-half or three hours probably, of activity. Then we say goodbye to P3/P4 and bring all of our tools back in and our tethers and start to work on changing out some things on S1, some tool boxes and the S-band transponder and a signal processor in the S-band communication system."
"Heide will be working on an electronic instrumentations antenna on the lab and I'll be heading up to the top of P6 to take care of some unfinished business up there from STS-97, on one balky latch up there, and then putting some clips on some bolts and finally bringing down a science experiment known as MISSE-5. I'll be up on the top for 45 minutes or so and Heide and I will really be separated. And then we join back up again and finish up probably a six, six-and--a-half hour EVA and then head back in."
If all goes well, the astronauts will get a day off the next day, holding a joint crew news conference, posing for a traditional crew photo and enjoying a joint meal with their space station colleagues while wrapping up a few final equipment transfers.
"For the late inspections, they did part of it docked, they did the port wing docked and based on their debrief with us post flight, that turned out to be much more difficult than they thought it was going to be," Jett said. "So based on their comments to us and our discussions with our flight directors, we decided to move the undock up about a half a day.
"We were going to do undock the morning of flight day 10, we moved it up to the afternoon of flight day nine. On flight day 10, we will repeat the RCC inspection that we did on flight day two. The same clearance views, the same procedures. Their experience told us doing that the second time, they were much more efficient at it, it went very smoothly as opposed to the docked inspection. That took a lot more time. ... We think that will help us late in the timeline."
The shuttle-station astronauts will enjoy a final joint meal the morning of Sept. 4 - flight day nine - before closing hatches between Atlantis and the station. Undocking is expected around 2:30 p.m. With Ferguson at the controls, Atlantis will pull directly away from the lab complex, moving to a point about 400 feet in front of the outpost before beginning a slow fly around.
"We all thought that we would (have finished station assembly) by this time on the calendar, and everybody's champing at the bit to get this construction going again. You've got a house that's only partially built, and there's so much more capability sitting on the ground that needs to go up - not just the trusses but for habitable volumes. The Japanese module is a beautiful science platform; it's magnificent. I've had a chance to work with those engineers and seen the module, and it's really magnificent. The European module, Columbus, is going to be fantastic. Node 2 is sitting at the Cape ready to go and it needs to be launched. So I think it's a great shot in the arm for everybody in the partnership to say, OK, let's get going again, and let's finish this job that we started."
But for Tanner and Jett, both making their fourth space flights, landing will mark the end of the line.
"We're looking at new careers, a major career transition after this flight, we know for sure as we do some things leading up to the mission it's likely the last time we will do them in our professional careers," Jett said. "Because we know we're not going to do it again, we're trying to take a little bit more time to appreciate some of those things. Having this crew be together for so long and be so close has made it even more special because you get to share it with someone you're really close to."
08/24/06: Countdown begins; crew arrives for final preps
The shuttle Atlantis' astronauts flew to Florida today to prepare for launch Sunday on a long-awaited flight to restart space station assembly. With forecasters predicting a 70 percent chance of good weather, liftoff from pad 39B is targeted for 4:30 p.m. Sunday.
"I hope you can tell by the smiles on our faces that we're very, very happy to finally be here in Florida to start the launch countdown," Commander Brent Jett told reporters at the shuttle runway. "Now there's been a lot of talk in the press lately about NASA being 'back' and I think we would all certainly agree with that talk. But we have a saying back in Texas that it's time to 'walk the walk.' Speaking for myself and my fellow crewmates, I can assure you we are ready for the challenge and we are anxious to restart the station assembly sequence. All we need is a little good weather Sunday and we'll be out of here."
Jett and his crewmates - pilot Chris Ferguson, Joe Tanner, Dan Burbank, Heidemarie Stefanyshyn-Piper and Canadian astronaut Steve MacLean - plan to spend the next two days reviewing their flight plan and relaxing before strapping in for launch Sunday.
Forecasters are predicting a 70 percent chance of acceptable weather Sunday, improving to 80 percent "go" Monday and Tuesday. NASA's launch strategy calls for back-to-back launch tries Sunday and Monday, then two more back-to-back tries Wednesday and Thursday to give four launch attempts in five days. Three more launch opportunities are available between then and the end of the launch window on Sept. 7.
While the afternoon weather is expected to be favorable this weekend, forecasters predict afternoon thunderstorms Friday and Saturday. As a result, the launch team moved up the start of Atlantis' countdown from 6 p.m. to noon today to give engineers a better chance for loading on-board oxygen and hydrogen for the shuttle's electricity producing fuel cells.
A hold at the T-minus 19 hour mark that normally lasts just four hours will be lengthened to 10 hours to make up for the early start of the countdown. When the count resumes at 2 a.m. Saturday, all subsequent activities will be synched up with the original schedule. An updated countdown timeline is posted on the CBS News STS-115 Quick-Look page:
http://www.cbsnews.com/network/news/space/currentglance.html
The goal of the 116th shuttle mission is to deliver and install a $372 million set of solar arrays and a complex rotary joint on the international space station, a complex job requiring back-to-back spacewalks, dual robot arm operations and tight coordination with flight controllers in Houston. It is the first in a series of assembly flights that rank as the most complex ever attempted by NASA.
Station assembly has been on hold since the Feb. 1, 2003, loss of the shuttle Columbia but with a successful test flight last month, NASA managers are counting on Atlantis' mission to restart the assembly sequence and clear the way for more frequent shuttle launchings.
"It's been six years since our payload has been at Kennedy," MacLean said. "It's been four years since Atlantis has been in preparation (for launch) and for us as a crew, it's been four and a half years as well. And finally, on Sunday, we're going to get to walk out to the pad for launch.
"For me, walking out to the pad on Sunday will be much like walking into an Olympic stadium for your athletic event. Many countries will be participating in a spirit of international cooperation and our families and our friends who believe in what we do will be in the front seats of the stadium. So I invite you all to watch what we do over the next week. It will be exciting. It's complex what we do, it's not easy. But with a team like this that I've been working with for the last four years and especially with the focus and dedication of the teams on the ground, I promise you we'll bring home a gold medal."
A detailed mission preview will be posted here later today, along with updates to the CBS News Space Reporter's Handbook and the SpaceCalc spreadsheet.
08/16/06: NASA clears Atlantis for Aug. 27 launch pending resolution of final issues
NASA managers today formally - and unanimously - cleared the shuttle Atlantis for blastoff Aug. 27 on a mission to restart space station assembly, pending resolution of two down-to-the-wire technical issues.
Bill Gerstenmaier, NASA's associate administrator for space flight, said engineers remain concerned about the status of so-called ice-frost ramps on the shuttle's external tank that prevent ice from forming around fittings that hold pressurization lines in place.
The ice-frost ramps remain classified "probable/catastrophic" in NASA's risk matrix, meaning there's a 50-50 chance a piece of foam could break away from one over the 100-flight design life of an orbiter and cause catastrophic damage.
Before Discovery's flight last month on the second post-Columbia mission, NASA's top safety manager and chief engineer dissented with the decision to proceed before a redesign was in place. NASA is working on a new ice-frost ramp design, but it won't be available until next year.
This time around, chief enginer Chris Scolese signed the Certificate of Flight Readiness without comment. Safety chief Bryan O'Connor appended an "exception" saying he concurred with the decision to launch because Administrator Mike Griffin accepted the known risk for the agency; because the programmatic need, cited earlier by Griffin, to get on with station assembly remained unchanged; and because the shuttle's risk posture was "no worse" now than it was for Discovery's flight last month.
Gerstenmaier said representatives of the Johnson Space Center and the Marshall Spaceflight Center weighed in with observations that NASA must continue its efforts to redesign the ice-frost ramps, but they too signed the CoFR, making the launch decision unanimous.
"There were no no-go votes," said Gerstenmaier. "The board's position is we are go for STS-115. We now give them the luxury of adding any other words they want beyond go, which we did last time, and both Marshall and JSC emphasized to us they would like to have the ice-frost ramps redesigned. And that's all they said. So it was essentially a unanimous decision by the board that we are go."
Engineers are still trying to figure out what caused problems with a critical thermostat in a hydraulic power unit aboard the shuttle Discovery during its flight last month. And managers are still debating what, if anything, to do about two of four bolts holding Atlantis' KU-band antenna in place at the front of the shuttle's cargo bay.
Shuttle program manager Wayne Hale said the thermostat issue is currently classified as an "unexplained anomaly," one that he would like to resolve before Aug. 27. But if not, he said he would be comfortable pressing ahead anyway because of redundancy in the hydraulic system.
The KU antenna bolts are another matter. The two forward bolts are known to be properly threaded and sufficiently engaged in capture nuts. The two aft bolts, however, may be only partially engaged because the bolts in question are too short.
The concern is that an insufficiently secured antenna box could break free during launch and fall the six-story length of the shuttle's payload bay with catastrophic results.
"We're not going to fly if we think there's a possibility the antenna could come off," said Griffin.
The mistake was made in the 1980s when Atlantis was built and the shuttle has flown 26 times in the current configuration. Both bolts are firmly torqued, albeit without the desired six to eight threads engaged, and they have not backed out any detectable amount. As such, some engineers believe NASA should simply launch Atlantis as is and replace the bolts after the upcoming flight.
Hale said today the fly-as-is option is still on the table. Engineers are carrying out a detailed analysis of launch vibrations in that area of the cargo bay to determine their effect on the antenna box and to find out if it can safely fly with just two fully engaged bolts.
"Having that small number of threads engaged is just not good practice and there are circumstances where those threaded fasteners can come out," Hale said. "So that is a poor design, or a poor application, and we need to rectify it. It's something that you really don't want to have."
But he did not rule out flying as is, if engineers can prove the box will remain securely in place with just two bolts. It seems more likely, however, that engineers will be asked to replace the bolts in question.
Kennedy Space Center engineers are refining a plan to do just that, but the repair job would be difficult, requiring technicians to build scaffolding on an extended access platform six stories above the shuttle's aft payload bay bulkhead.
Because of ongoing hazardous operations at pad 39B, engineers cannot open Atlantis' cargo bay doors until Friday. Hale said he hopes to make a decision on how to proceed by Friday or Saturday.
Launch director Mike Leinbach said he believes the repairs, if required, can be completed in time to support the Aug. 27 launch date, but safety will be the watchword. Even with safety nets and tethers, working in a cramped space on scaffolding six stories up surrounded by fragile flight hardware raises the possibility of inadvertent damage to other equipment.
"It all looks good on paper, in the CAD modeling," Leinbach said. "Once we get into the job, if we get scared by something and we shouldn't proceed on we're going to stand down. ... It's not a long job, it's probably two days total to do this and out of those two days, probably 44 hours of the 48 is the access installation and removal. The bolt change out itself is probably going to be very straight forward assuming we don't get any 'gotchas' when we get out there."
Leinbach said engineers currently have two full days of contingency time left in the processing schedule to handle unexpected problems. On paper, at least, the bolt change out can be accomplished without delaying launch.
Atlantis' countdown is scheduled to begin next week at 6 p.m. on Thursday, Aug. 24. Liftoff is targeted for 4:30 p.m. on Aug. 27.
08/15/06: Flight readiness review begins; KU bolt update; risk matrix discussion
NASA managers kicked off a two-day engineering review today to assess the shuttle Atlantis' readiness to blast off Aug. 27 on a long-awaited flight to restart space station assembly.
Along with discussing the shuttle's external tank and the ongoing threat of falling foam insulation, engineers and managers also will discuss what to do about bolts holding the shuttle's KU-band antenna in place on the forward right wall of the ship's payload bay.
A recent engineering review indicates two of the four bolts holding the KU antenna support box in place are too short. Engineers cannot directly inspect the bolts at the launch pad, but a paperwork review shows the bolts in question may be engaged by less than 2.4 threads. The requirement is 8.4 threads engaged.
While the bolts were properly torqued, and while Atlantis has flown 26 flights in the current configuration, engineers cannot prove the bolts have not, or will not, back out at some point, allowing the antenna box to break free. Should it break loose during launch, it could fall the length of the shuttle's six-story cargo bay and cause catastrophic damage.
Gaining access to the KU antenna at the launch pad is extremely difficult, but sources say the engineering community wants to replace the bolts rather than launch Atlantis as is. Kennedy Space Center engineers have developed a plan to make the unprecedented repairs, but it's not yet clear what impact such work might have on Atlantis' launch processing schedule.
Assuming managers at the flight readiness review approve the current launch target, Atlantis countdown would begin Aug. 24 for a liftoff at 4:30 p.m. on Aug. 27. The launch window closes Sept. 7. The current plan permits up to seven launch attempts within that window.
The KU bolt fix, if approved, would require engineers to extend an access platform into the open cargo bay from the payload change out room at pad 39B. A second platform then would be erected on the first to reach the antenna box. Safety nets would be required because the work would take place at a height of nearly 60 feet above the shuttle's aft bulkhead. In addition, the shuttle's robot arm and a 50-foot-long boom used to inspect the ship's heat shield would have to be moved to provide access.
A technician, resting on his side in very close quarters beside Atlantis' external airlock, would then remove and replace the two bolts in question. A major concern with working in such tight quarters is inadvertent damage to nearby equipment, but engineers believe they can safely do the work.
A variety of other technical issues will be discussed at the flight readiness review, including the status of Atlantis external fuel tank.
Atlantis will fly with an external tank that is virtually identical to the one used to launch the shuttle Discovery last month. During the FRR before that flight, NASA's top safety manager and chief engineer voted against launching because so-called ice-frost ramps on the external tank, made up of hand-crafted foam insulation, were formally classified as "probable/catastrophic."
That classification means that over the original 100-flight life of a space shuttle, there is a 50-50 chance that a piece of foam large enough to cause catastrophic damage would break away from an ice-frost ramp and hit the spacecraft.
The ice-frost ramps received that classification because they are made up of foam that is manually applied on top of other foam. Recent engineering studies show such foam-on-foam buildups can experience cracks because of temperature extremes and pressure changes during fueling cycles. Such cracks, in turn, can lead to foam shedding.
Under NASA's existing FRR procedures, the "probable/catastrophic" classification left safety director Bryan O'Connor and chief engineer Chris Scolese with no choice but to vote "no-go" at the end of Discovery's readiness review.
NASA Administrator Mike Griffin ultimately approved Discovery's launch over their formal objections, saying he didn't believe the probable/catastrophic classification was justified and that the benefits of keeping the shuttle on the ground until the ramps were redesigned were outweighed by the programmatic need to restart station assembly.
NASA currently is in the process of redesigning the ice-frost ramps, but no major changes have been implemented since Discovery's flight and it is assumed O'Connor and Scolese will vote the same way they did last June.
During an interview shortly before Discovery took off July 4, Griffin explained his earlier decision in detail.
"In order to get this to be a hazard, we have to assume that this flight is going to release the maximum amount of mass we've ever seen," he told CBS News. "Probably that's not going to happen, right? But that's what we assume. Then we have to assume the mass comes off in chunks that are bigger than we've ever seen. The biggest chunk we've ever seen come off with this mechanism is .084 pounds. So we set the limit on this thing at .25 pounds, which is the biggest chunk of mass that you could get off of an ice-frost ramp because that's what the whole thing weighs. We've never actually seen that, but we assume that could happen.
"Then we have to assume that all the mass comes off and it comes off in big chunks and it comes off at the worst possible time, which is about a seven or eight or 10 second window in there ... And then we have to say it hits the worst place on the orbiter. So if all that happens, then we have a hazard that we think rises to a level of real concern.
"Now, we're not ignoring it, we're going to redesign the ice-frost ramps and we're going to fix it. But I ask myself as an engineer, what are the odds that all those four bad things are going to come true over the next two or three flights while we do a redesign? And I say to myself, not very high. And in fact, when we go and analytically study that, the odds come down to like 1-in-400 or 500, which is well less than many other risks we're taking on the orbiter."
Griffin agreed with the observation that complex systems fail in complex ways and worst-case aviation failures do, in fact, occur. But he said the risk posed by the ice-frost ramps is less, in his view, than the overall risk of flying the shuttle at all.
"Rotating machinery would be well ahead on my list," he said, referring to the shuttle's main engines "Our micrometeorite and orbital debris hazard is 1-in-200. I remember flight readiness reviews from my youth where every moment was soaked up in turbopump seals. There are other hazards on this machine that we accept in order to fly it.
"Now that's not good, either, and we're trying to transition to a new system ... which will be at least 10 times safer than the shuttle on its best day. We can do better and we will do better. ... But if I can get individual risks like foam debris down to one in many hundreds, then that's very acceptable in comparison to the other risks which we accept to fly this machine at all. And that's where I think we are.
"Everyone says why'd you overrule your chief engineer and your safety guy? Well, that's why. Because I believe when we analyze this thing in terms of what is likely to happen as opposed to a worst on worst on worst, the risk is very acceptable."
08/15/06: Mission flight plan updated
NASA flight planners have updated the timeline for shuttle mission STS-115, moving space station undocking up one day and deferring late inspection of Atlantis' nose cap and wing leading edges until the day after separation. A summary timeline is posted below. The complete flight plan update is posted on the CBS News STS-115 Quick-Look page.
08/13/06: Engineers troubleshoot bolt issue
Engineers are trying to determine whether critical bolts holding the shuttle Atlantis' KU-band antenna box in place are securely threaded, a potentially serious issue that could require tricky repairs before the ship's Aug. 27 launch, sources said Sunday.
A two-day flight readiness review to assess Atlantis' ground processing, to resolve open issues and to set an official launch date begins Tuesday at the Kennedy Space Center. The launch window for the 116th shuttle mission opens Aug. 27 at 4:30 p.m. and closes Sept. 7.
The KU-band antenna bolt issue will be discussed Monday, but it's not yet clear whether the issue can be resolved before the flight readiness review begins or whether additional work will be needed to determine what, if anything, needs to be done.
The issue involves four bolts that hold the antenna support box to the forward right side of Atlantis' cargo bay. The KU-band antenna is used to relay voice, video and data between the shuttle and NASA's fleet of communications satellites.
During an earlier launch campaign, engineers discovered problems with a certain type of bolt that in some cases were too short and not sufficiently threaded, or screwed in. Engineers began an assessment of similar bolts used elsewhere in the shuttle.
As it turns out, the same type bolts are used to secure the shuttle's KU-band antenna box to the payload bay wall. Engineers replaced the bolts in the shuttles Discovery and Endeavour but not in Atlantis.
The bolts have been in place since the antenna was installed aboard Atlantis and there has never been a problem. But it is known that some of the bolts could be engaged just a few threads worth because of a "tolerance stackup" in the way the bolts and washers are installed, according to engineers familiar with the matter.
Should the box break free during ascent, it would fall the length of the shuttle's 60-foot-long cargo bay and could cause catastrophic damage.
The bolts in question cannot be easily inspected at the launch pad. Kennedy Space Center engineers are studying paperwork and earlier analyses to determine whether the bolts are, in fact, sufficiently threaded. At the same time, sources said, they also are studying ways to replace the bolts at the pad, if necessary, a procedure that has never been done before.
Atlantis' launch window is defined by the international space station's orbit and by a post-Columbia requirement to launch two missions in daylight for photo documentation of the shuttle's heat shield and external tank foam insulation.
Because of unexpected foam shedding during the first post-Columbia mission last year, NASA extended the daylight requirement to the third flight in the sequence.
The shuttle Discovery successfully flew in July and a repeat performance by Atlantis would clear the way for the resumption of night launchings, greatly expanding available launch windows.
But if Atlantis isn't off the ground by the end of the September window, NASA would be faced with the prospect of just two launch days in October, none in November and just one in December. As such, agency engineers want to resolve the bolt issue as soon as possible.
08/09/06: Atlantis crew ready to kick start station assembly
The crew of the shuttle Atlantis reviewed launch pad emergency procedures today and in a brief question-and-answer session with reporters, described their upcoming station assembly flight as one of the most complex missions yet attempted.
But commander Brent Jett said that level of complexity will be the rule, not the exception, on all upcoming flights as NASA attempts to finish the international space station before the shuttle is retired in 2010.
"Every crew likes to say boy, this is one of the most complex missions we've every flown," Jett said at the base of launch pad 39B. "They're all that way. And they'll all be that way until we stop flying in 2010."
Jett, pilot Chris Ferguson, flight engineer Dan Burbank, Joe Tanner, Steve MacLean and Heidemarie Stefanyshyn-Piper arrived at the Kennedy Space Center Monday to review emergency procedures and to participate in a full-up dress-rehearsal countdown Thursday.
NASA managers will meet next week for a formal flight readiness review to clear Atlantis for launch. The launch window opens at 4:30 p.m. Aug. 27 and closes Sept. 7.
The goal of the 116th shuttle mission is to attach a huge set of solar arrays to the left side of the space station's main truss along with a complex rotary joint that will enable the panels to track the sun to maximize electrical output. Three spacewalks by Tanner, Piper, Burbank and MacLean, working in two-person teams, will be needed to hook up, activate and check out the new equipment.
The station ultimately will feature four sets of arrays, two on each end of the main truss. A set of arrays currently mounted to a truss atop the station's multi-hatch Unity module will be repositioned late next summer beside the arrays going up aboard Atlantis.
Atlantis' flight represents a major milestone for NASA, the resumption of space station assembly three years after the Columbia disaster. Assuming the shuttle's external tank doesn't shed any major pieces of foam insulation, NASA is expected to resume night launchings in December when Discovery is scheduled to return to the station.
"Every crew and every mission control team has to be on their game when we fly these assembly missions," Jett said. "We've got to do them right. We can handle some setbacks, we can deal with some problems, but we have to perform these missions well and we have only a limited amount of time to do it. They're all important, we treat them all as very important missions.
"If we do our jobs right, we'll get to 2010 and we'll retire the shuttle safely, we'll see it come to a 'wheels stopped' not too far from here and we'll have a complete station. That's what we're really all looking forward to."
As for the sheer complexity of the assembly tasks, "I think all the missions between now and 2010 that involve station assembly are going to be extremely complex," Jett said. "You could probably make the case that each one is slightly more complex than the one that precedes it. We're flying hardware that has no history in space."
The rotary joints that ultimately will let the station's arrays rotate to track the sun have been tested on the ground but "we don't have any history with them on orbit," Jett said. "So those represent a special challenge in terms of both engineering and operations."
"I think the most challenging thing for us on this flight is going to be our timeline," Jett said. "We've put together a very aggressive first five or six days of the flight, we did that deliberately. It's probably the most aggressive timeline that's been flown on the shuttle ever.
"We think we're ready for it. We've been in training for four-and-a-half years and we have some options if we get a little bit behind where we can relax that timeline. But that's going to be the most challenging part for us, getting the solar arrays deployed on flight day six."
The astronauts, flight directors and mission managers will participate in a full day of background briefings and interviews Friday at the Johnson Space Center in Houston. A detailed mission preview will be posted here as soon as possible thereafter.
08/07/06: Astronauts arrive for practice countdown
The crew of the shuttle Atlantis flew to the Kennedy Space Center today for launch-site training and to participate in a dress-rehearsal countdown Thursday that will set the stage for blastoff Aug. 27 on a space station construction mission.
Commander Brent Jett, pilot Chris Ferguson, flight engineer Dan Burbank, Joe Tanner, Steve MacLean and Heidemarie Stefanyshyn-Piper touched down in three T-38 jet trainers around 5:40 p.m. after a flight from Houston.
"We're very happy to be here, like all crews are for TCDT (terminal countdown demonstration test)," Jett said at the runway. "The training events of this week mark the last milestones for us in flight preparations. We're looking forward to a good week of training with the launch team and a real smooth countdown, or at least a smooth practice countdown, on Thursday. Once that's complete, we'll be real anxious to get back here at the end of the month and go into a real countdown and launch.
"It's a beautiful day today," he added. "I was kind of (thinking) we ought to save some of these days for the end of the month because I think we're going to need them. ... If we get a day like today on Aug. 27, we'll be in good shape."
The goal of the 116th shuttle mission is to attach and deploy a huge set of solar arrays on the port side of the space station's main truss. Launch is targeted for 4:30 p.m. on Aug. 27, but that date won't be official until after a two-day flight readiness review next week.
Atlantis' launch window extends through Sept. 7. Assuming the shuttle gets off within that window - and assuming minimal amounts of foam insulation fall off the ship's external tank - NASA managers are expected to resume night launchings, greatly expanding the agency's launch opportunities.
08/03/06: NASA sticks with Aug. 27 launch target; lighting doesn't support Aug. 26
NASA managers today decided to stick with an Aug. 27 launch target for shuttle Atlantis based on an analysis that indicates orbital lighting would not be sufficient for a launch on Aug. 26.
As part of NASA's recovery from the Columbia disaster, the agency wants to launch Atlantis in daylight and still have enough light in orbit after the climb to space to permit photo documentation of the foam insulation on the shuttle's external fuel tank.
Because of a potential conflict with launch of a Russian Soyuz spacecraft carrying the station's next full-time crew, Atlantis' launch window currently extends through Sept. 7. NASA managers asked engineers to assess the possibility of launching Atlantis as early as Aug. 26 to maximize their chances of getting the shuttle off before the window closes.
That's important because once the August/September window expires, NASA will only have three useable lighted launch days between then and the end of the year - two in late October and one in December.
But as it turns out, critical areas of the tank's insulation - so-called ice-frost ramps and the nearby area where longer protuberance air-load, or PAL, ramps were once in place, will not be sufficiently illuminated on Aug. 26 to permit the sort of photo documentation engineers want.
As a result, NASA is sticking with the Aug. 27 launch target. Barring major problems, that date is expected to become official at the conclusion of a two-day flight readiness review Aug. 16.
08/02/06: Atlantis finally moved to launch pad
Finally catching a break from the weather, the shuttle Atlantis was hauled to its ocean-side launch pad early today for final preparations before blastoff at the end of the month on a space station assembly mission.
The 4.2-mile move from the Vehicle Assembly Building began at 1:05 a.m., two days late because of showers and thunderstorms that pounded Cape Canaveral Sunday night and Monday. The shuttle's mobile launch platform was "hard down" at the pad by 8:54 a.m.
Atlantis's crew - commander Brent Jett, pilot Chris Ferguson, flight engineer Dan Burbank, Joe Tanner, Steve MacLean and Heidemarie Stefanyshyn-Piper - will fly to the Kennedy Space Center next week to participate in a dress-rehearsal countdown Aug. 10.
Launch currently is targeted for Aug. 27, but NASA managers are considering the possibility of moving the flight up one day to Aug. 26.
Atlantis' launch window is based on the international space station's orbit, the angle between the sun and the plane of the station's orbit and lighting conditions for photo documentation of the ship's external tank and heat shield. Based on those factors, the launch window extends from Aug. 27 through Sept. 13.
But any launch past Sept. 7 would put the shuttle in conflict with launch of a Russian Soyuz capsule carrying the station's next full-time crew. NASA managers and their Russian counterparts want to ensure at least one day between undocking of Atlantis and arrival of the Soyuz. As a result, if Atlantis launches between Aug. 27 and Sept. 3, the Soyuz will take off Sept. 14. A shuttle launch between Sept. 4 and Sept. 7 would result in a Soyuz launch Sept. 18.
A Soyuz launch later than Sept. 18 would result in a dead-of-night landing for the returning station crew, a scenario the Russians want to avoid. That means Atlantis must get off the ground by Sept. 7 at the latest unless the Russians change their launch strategy.
To ensure as many launch attempts as possible, NASA engineers are assessing whether orbital lighting would be sufficient for a shuttle launch as early as Aug. 26. At issue is whether critical areas of the external tank would be illuminated sufficiently for photo documentation after separation from the shuttle.
But Aug. 26 will be a challenge regardless of orbital lighting. Given Atlantis' delayed move to the pad, the launch team only has two days of contingency time left in the pad processing schedule to handle unexpected problems.
The goal of the 116th shuttle mission is to install two new truss segments - port 3 and port 4 - on the left end of the station's main power and cooling truss. The port 3 truss segment features a complex rotary joint that will enable two huge solar panels making up the port 4 segment to track the sun as required to provide maximum power.
Earlier today, the station's mobile transporter, used to carry the lab's robot arm from point to point along the main truss, was moved from work site 4 to work site 7 on the end of the port 1 truss segment to await Atlantis' arrival. The station arm, mounted on the transporter, will be used to move the new truss segments brought up by Atlantis into position for attachment to P1 (there is no P2 segment).
The STS-115 flight plan is being revised to reflect recent changes. But here are two timelines, based on the latest rendezvous projections and a recent decision to move up undocking one day, for launch attempts Aug. 26 and Aug. 27 (in EDT and mission elapsed time):
08/26/06
08/28/06
08/29/06
08/30/06
08/31/06
09/01/06
09/03/06
09/06/06
08/27/06
08/29/06
08/30/06
08/31/06
09/01/06
09/02/06
09/04/06
09/07/06
If NASA can get Atlantis off within the available window, and if the shuttle's external tank doesn't shed any significant amounts of foam insulation, the space agency will remove a self-imposed restriction to only launch in daylight, greatly expanding the available launch windows for subsequent flights.
But if Atlantis fails to get off in the August/September window, the agency will face the prospect of just three useable launch days - Oct. 26, 27 and Dec. 23 - before the end of the year because of lighting and temperature constraints based on the station's orbit.
07/27/06: Launch window opening moves up one day to Aug. 27
An analysis of orbital lighting for photo documentation of the shuttle Atlantis' external tank indicates favorable conditions for a launch attempt Aug. 27, one day earlier than had been targeted, officials said today. Engineers are still assessing whether orbital lighting would permit a launch as early as Aug. 26.
At a shuttle program requirements change board meeting today, shuttle program manager Wayne Hale directed the lighting analysis team to report back in one week on whether Aug. 26 is feasible. In the meantime, the opening of Atlantis' launch window has been moved up one day to Aug. 27. An official launch date will be set at the conclusion of a two-day flight readiness review Aug. 16.
As it now stands, the shuttle's launch window will close Sept. 7. Orbital lighting would permit a launch as late as Sept. 13, but any launch past Sept. 7 would result in a conflict between the shuttle and a Russian Soyuz capsule that will deliver the station's next full-time crew.
The flight plan posted on the CBS News STS-115 Quick-Look page has been updated to reflect a possible launch on Aug. 27.
07/24/06: Atlantis moved to Vehicle Assembly Building
The shuttle Atlantis was moved from its Orbiter Processing Facility hangar to the nearby Vehicle Assembly Building today for attachment to an external fuel tank and rocket boosters.
Perched atop a squat multi-wheel transporter, Atlantis began its roll over around 7:30 a.m. and the ship was safely inside the cavernous assembly building by 8:45 a.m. Over the next few days, engineers will bolt the spacecraft to its external tank and if all goes well, the shuttle stack will be hauled to launch pad 39B next Monday for final pre-launch preparations.
Liftoff on the 116th shuttle mission is targeted for Aug. 27 or 28, depending on orbital lighting for photo documentation of the external tank. An official launch date is expected to be announced at the conclusion of a two-day flight readiness review Aug. 16.
07/21/06: Setting up STS-115 pages; Atlantis prepped for roll over to VAB CORRECTED at 1:45 p.m. to fix launch date typos
Editor's note...
STS-115 Status Reports:
STS-115 Quick Look Page:
The initial edition of SpaceCalc for PCs and Macintosh computers is available on the Downloads page:
http://www.cbsnews.com/network/news/space/downloads.html
Comments, suggestions and corrections welcome!
A preliminary analysis of post external tank separation lighting indicates Aug. 27 may be acceptable. While areas of interest on the tank likely will be shadowed for crew hand-held camera photography, it appears at least marginally acceptable for a higher-priority camera mounted in the belly of the shuttle where a propellant feedline enters the orbiter.
Target launch dates will be discussed at next Thursday's program requirements change board - PRCB - meeting at the Johnson Space Center in Houston.
Here's the upcoming processing schedule as currently known: (all dates subject to change)
P3/P4 truss elements attached to station (graphic: Boeing)
In the meantime, here is a detailed mission "walkthrough" from NASA. Readers are assumed to be familiar with NASA acronyms!
Flight Day 1
Flight Day 2
Flight Day 3
P3/P4 truss unberthing and handoff (Boeing)
Flight Day 4
Flight Day 5
Flight Day 6
Flight Day 7
Flight Day 8
Flight Day 9
Flight Day 10
Flight Day 11
Flight Day 12
Dummy copy indicating a launch scrub was inadvertently posted here earlier this morning. We apologize for the filing error.
DATE/EDT EVEMT
_________________________________________________________________
05:30:00 AM **NASA TV coverage begins
05:57:00 AM **Astronaut photo opportunity
07:11:00 AM **Crew weather briefing
07:21:00 AM **Astronauts don pressure suits
07:45:00 AM **Resume countdown (T-minus 3 hours)
07:50:00 AM Crew departs O&C building
08:20:00 AM Crew ingress
09:10:00 AM Astronaut comm checks
09:35:00 AM Hatch closure
10:10:00 AM White room closeout
10:25:00 AM **Begin 10-minute built-in hold (T-minus 20m)
10:27:00 AM **NASA test director countdown briefing
10:35:00 AM **Resume countdown (T-minus 20m)
10:36:00 AM Backup flight computer to OPS 1
10:40:00 AM KSC area clear to launch
10:46:00 AM **Begin final built-in hold (T-minus 9m)
10:56:37 AM **NTD launch status verification
11:31:37 AM **Resume countdown (T-minus 9m)
11:33:07 AM Orbiter access arm retraction
11:35:00 AM Launch window opens (actual: 11:35:37 a.m.)
11:35:37 AM Hydraulic power sy stem (APU) start
11:35:42 AM Terminate LO2 replenish
11:36:37 AM Purge sequence 4 hydraulic test
11:36:37 AM IMUs to inertial
11:36:42 AM Aerosurface profile
11:37:07 AM Main engine steering test
11:37:42 AM LO2 tank pressurization
11:38:02 AM Fuel cells to internal reactants
11:38:07 AM Clear caution-and-warning memory
11:38:37 AM Crew closes visors
11:38:40 AM LH2 tank pressurization
11:39:47 AM SRB joint heater deactivation
11:40:06 AM Shuttle GPCs take control of countdown
11:40:16 AM SRB steering test
11:40:30 AM Main engine start (T-6.6 seconds)
11:40:37 AM SRB ignition (LAUNCH)
DATE/EDT EVEMT
_________________________________________________________________
Thursday, Sept. 7
11:30:00 PM Fuel cell integrity checks complete
11:45:00 PM **Begin 2-hour built-in hold (T-minus 6 hours)
11:55:00 PM **Safe-and-arm PIC test
Friday, Sept. 8
12:15:00 AM **External tank ready for fueling
12:35:00 AM **Mission management team tanking meeting
12:42:00 AM **Crew wakeup
01:10:00 AM **Orbiter ready for ET loading
01:45:00 AM **Resume countdown (T-minus 6 hours)
01:45:00 AM LO2, LH2 transfer line chilldown
01:55:00 AM Main propulsion system chill down
01:55:00 AM LH2 slow fill
02:12:00 AM Astronaut breakfast; medical checks
02:15:00 AM LO2 slow fill
02:31:00 AM Hydrogen ECO sensors go wet
02:35:00 AM LO2 fast fill
02:45:00 AM LH2 fast fill
04:00:00 AM LH2 topping
04:40:00 AM LH2 replenish
04:45:00 AM LO2 replenish
04:45:00 AM **Begin 3-hour built-in hold (T-minus 3 hours)
04:45:00 AM **Closeout crew to white room
04:45:00 AM **External tank in stable replenish mode
05:00:00 AM **Astronaut support personnel comm checks
05:30:00 AM **Pre-ingress switch reconfig
05:30:00 AM **NASA TV coverage begins
05:57:00 AM **Astronaut photo opportunity
07:11:00 AM **Crew weather briefing
07:21:00 AM **Astronauts don pressure suits
07:45:00 AM **Resume countdown (T-minus 3 hours)
07:50:00 AM Crew departs O&C building
08:20:00 AM Crew ingress
09:10:00 AM Astronaut comm checks
09:35:00 AM Hatch closure
10:10:00 AM White room closeout
10:25:00 AM **Begin 10-minute built-in hold (T-minus 20m)
10:27:00 AM **NASA test director countdown briefing
10:35:00 AM **Resume countdown (T-minus 20m)
10:36:00 AM Backup flight computer to OPS 1
10:40:00 AM KSC area clear to launch
10:46:00 AM **Begin final built-in hold (T-minus 9m)
10:56:37 AM **NTD launch status verification
11:31:37 AM **Resume countdown (T-minus 9m)
11:33:07 AM Orbiter access arm retraction
11:35:00 AM Launch window opens (actual: 11:35:37 a.m.)
11:35:37 AM Hydraulic power sy stem (APU) start
11:35:42 AM Terminate LO2 replenish
11:36:37 AM Purge sequence 4 hydraulic test
11:36:37 AM IMUs to inertial
11:36:42 AM Aerosurface profile
11:37:07 AM Main engine steering test
11:37:42 AM LO2 tank pressurization
11:38:02 AM Fuel cells to internal reactants
11:38:07 AM Clear caution-and-warning memory
11:38:37 AM Crew closes visors
11:38:40 AM LH2 tank pressurization
11:39:47 AM SRB joint heater deactivation
11:40:06 AM Shuttle GPCs take control of countdown
11:40:16 AM SRB steering test
11:40:30 AM Main engine start (T-6.6 seconds)
11:40:37 AM SRB ignition (LAUNCH)
Assuming an on-time liftoff, here is an abbreviated flight plan of critical mission events (in EDT and mission elapsed time; a complete flight plan and NASA's television schedule (rev. E) are posted on the CBS News STS-115 Quick-Look page):
DATE/EDT DD HH MM EVENT
_____________________________________________________________
09/08/06
Fri 11:41 AM 00 00 00 STS-115 Launch (flight day 1)
Fri 05:41 PM 00 06 00 Crew sleep begins
09/09/06
Sat 01:41 AM 00 14 00 Crew wakeup
Sat 06:31 AM 00 18 50 Heat shield survey begins
Sat 04:41 PM 01 05 00 Crew sleep begins
09/10/06
Sun 12:41 AM 01 13 00 STS/ISS crew wakeup
Sun 07:55 AM 01 20 14 Atlantis docks with space station
Sun 10:31 AM 01 22 50 SRMS unberths P3/4
Sun 11:51 AM 02 00 10 SRMS hands P3/P4 to SSRMS
Sun 04:41 PM 02 05 00 STS crew sleep begins (EV1/EV2 in airlock)
09/11/06
Mon 12:41 AM 02 13 00 STS/ISS crew wakeup
Mon 04:21 AM 02 16 40 P1/P3 bolts engaged
Mon 05:41 AM 02 18 00 EVA-1: Airlock egress; tool setup
Mon 12:01 PM 03 00 20 EVA-1: Airlock ingress/repress
Mon 04:41 PM 03 05 00 STS crew sleep begins (EV3/EV4 in airlock)
09/12/06
Tue 12:41 AM 03 13 00 STS/ISS crew wakeup
Tue 05:41 AM 03 18 00 EVA-2: Airlock egress; setup
Tue 12:01 PM 04 00 20 EVA-2: Airlock repressurization
Tue 04:41 PM 04 05 00 STS crew sleep begins
Tue 07:26 PM 04 07 45 MCC: 4A solar array mast deploy (1 section)
Tue 09:01 PM 04 09 20 MCC: 2A solar array mast deploy (1 section)
09/13/06
Wed 12:41 AM 04 13 00 STS/ISS crew wakeup
Wed 04:21 AM 04 16 40 STS: 4A mast deploy to 49 percent
Wed 05:01 AM 04 17 20 STS: 4A mast deploy to 100 percent
Wed 05:51 AM 04 18 10 STS: 2A mast deploy to 49 percent
Wed 06:31 AM 04 18 50 STS: 2A mast deploy to 100 percent
Wed 04:41 PM 05 05 00 STS crew sleep begins (EV1/EV2 in airlock)
09/14/06
Thu 12:41 AM 05 13 00 STS/ISS crew wakeup
Thu 05:41 AM 05 18 00 EVA-3: Airlock egress/setup
Thu 12:01 PM 06 00 20 EVA-3: Airlock repressurization
Thu 04:41 PM 06 05 00 STS crew sleep begins
09/15/06
Fri 12:41 AM 06 13 00 STS/ISS crew wakeup
Fri 03:41 AM 06 16 00 STS crew off duty time begins
Fri 04:41 PM 07 05 00 STS crew sleep begins
09/16/06
Sat 12:41 AM 07 13 00 STS/ISS crew wakeup
Sat 09:58 AM 07 22 17 Atlantis undocks from space station
Sat 03:41 PM 08 04 00 STS/ISS crew sleep begins
Sat 11:41 PM 08 12 00 STS crew wakeup
09/17/06
Sun 03:41 AM 08 16 00 Heat shield survey
Sun 03:11 PM 09 03 30 Crew sleep begins
Sun 11:11 PM 09 11 30 Crew wakeup
09/18/06
Mon 01:46 AM 09 14 05 Cabin stow begins
Mon 03:11 PM 10 03 30 Crew sleep begins
Mon 11:11 PM 10 11 30 Crew wakeup
09/19/06
Tue 06:07 AM 10 18 26 Deorbit ignition (orbit 171)
Tue 07:10 AM 10 19 29 Landing
02:35 a.m., 09/06/06, Update: Shuttle fueling on hold; fuel cell problem
Sunday 09/03/06
08:00:00 AM Countdown begins
Monday 09/04/06
12:00:00 AM ** Begin 4-hour built-in hold
04:00:00 AM ** Resume countdown
05:30:00 AM Fuel cell oxygen loading begins
08:00:00 AM Fuel cell oxygen load complete
08:00:00 AM Fuel cell hydrogen loading begins
10:30:00 AM Fuel cell hydrogen load complete
12:00:00 PM ** Begin 10-hour built-in hold
10:00:00 PM ** Countdown resumes (now in synch with standard count)
Tuesday 09/05/06
06:00:00 AM ** Begin 13-hour 33-minute hold
03:00:00 PM ** Rotating service structure to park position
07:33:00 PM ** Resume countdown
08:43:00 PM Fuel cell activation
10:33:00 PM Final fueling preps; launch area clear
Wednesday 09/06/06
12:33:00 AM ** Begin 2-hour built-in hold (T-minus 6 hours)
01:03:00 AM ** External tank ready for fueling
01:23:00 AM ** Mission management team go/no-go tanking meeting
02:33:00 AM ** Resume countdown (T-minus 6 hours)
02:33:00 AM Liquid oxygen/hydrogen transfer line chilldown
02:43:00 AM Liquid hydrogen (LH2) slow fill
03:03:00 AM Liquid oxygen (LO2) slow fill
03:23:00 AM LO2 fast fill
03:33:00 AM LH2 fast fill
05:33:00 AM ** Begin 3-hour built-in hold (T-minus 3 hours)
05:33:00 AM ** External tank in stable replenish mode
07:59:00 AM ** Astronaut weather briefing
08:09:00 AM ** Astronauts don pressure suits
08:33:00 AM Resume countdown (T-minus 3 hours)
08:39:00 AM Astronauts depart crew quarters
09:09:00 AM Crew straps in
09:58:00 AM Astronaut communications checks
10:23:00 AM Hatch closed
11:13:00 AM ** Begin 10-minute built-in hold (T-minus 20m)
11:23:00 AM ** Resume countdown (T-minus 20m)
11:24:00 AM Backup flight computer loads OPS 1 software
11:34:00 AM ** Begin final built-in hold (T-minus 9m)
11:44:49 AM ** NASA test director launch status verification
12:19:49 PM ** Resume countdown (T-minus 9m)
12:23:49 PM Hydraulic power system (APU) start
12:25:54 PM LO2 tank pressurization
12:26:52 PM LH2 tank pressurization
12:28:18 PM Shuttle computers take control of countdown
12:28:49 PM Launch
If Atlantis is delayed Wednesday, the crew will have two more launch opportunities before the current September launch window closes: at 12:03:07 p.m. Thursday and at 11:40:35 a.m. Friday. After that, the flight would be delayed to late October unless NASA relaxes a self-imposed requirement to launch Atlantis in daylight. NASA managers are in the process of reviewing that rationale.
09/06/06
Wed 12:29 PM 00 00 00 STS-115 Launch (flight day 1)
Wed 03:24 PM 00 02 55 Robot arm (SRMS) checkout
Wed 04:54 PM 00 04 25 External tank video downlink
Wed 06:29 PM 00 06 00 Crew sleep begins
09/07/06
Thu 02:29 AM 00 14 00 Crew wakeup
Thu 05:59 AM 00 17 30 Robot arm heat shield survey
Thu 05:29 PM 01 05 00 Crew sleep begins
09/08/06
Fri 01:29 AM 01 13 00 STS/ISS crew wakeup
Fri 08:37 AM 01 20 08 Atlantis docks with space station
Fri 11:19 AM 01 22 50 SRMS unberths P3/4 solar array truss
Fri 05:29 PM 02 05 00 STS crew sleep begins (EV1/EV2 in airlock)
09/09/06
Sat 01:29 AM 02 13 00 STS/ISS crew wakeup
Sat 05:09 AM 02 16 40 Solar array truss bolted in place
Sat 06:29 AM 02 18 00 EVA-1: Airlock egress; tool setup
Sat 12:49 PM 03 00 20 EVA-1: Airlock ingress/repress
Sat 05:29 PM 03 05 00 STS crew sleep begins (EV3/EV4 in airlock)
09/10/06
Sun 01:29 AM 03 13 00 STS/ISS crew wakeup
Sun 06:29 AM 03 18 00 EVA-2: Airlock egress; setup
Sun 12:49 PM 04 00 20 EVA-2: Airlock repressurization
Sun 05:29 PM 04 05 00 STS crew sleep begins
Sun 08:24 PM 04 07 55 MCC: 4A solar array mast deploy (1 section)
Sun 09:54 PM 04 09 25 MCC: 2A solar array mast deploy (1 section)
09/11/06
Mon 01:29 AM 04 13 00 STS/ISS crew wakeup
Mon 05:04 AM 04 16 35 STS: 4A solar array mast to 49 percent
Mon 05:44 AM 04 17 15 STS: 4A solar array mast to 100 percent
Mon 06:44 AM 04 18 15 STS: 2A solar array mast to 49 percent
Mon 07:24 AM 04 18 55 STS: 2A solar array mast to 100 percent
Mon 05:29 PM 05 05 00 STS crew sleep begins (EV1/EV2 in airlock)
09/12/06
Tue 01:29 AM 05 13 00 STS/ISS crew wakeup
Tue 06:29 AM 05 18 00 EVA-3: Airlock egress/setup
Tue 12:49 PM 06 00 20 EVA-3: Airlock repressurization
Tue 05:29 PM 06 05 00 STS crew sleep begins
09/13/06
Wed 01:29 AM 06 13 00 STS/ISS crew wakeup
Wed 08:49 AM 06 20 20 Joint crew news conference
Wed 05:29 PM 07 05 00 STS crew sleep begins
09/14/06
Thu 01:29 AM 07 13 00 STS/ISS crew wakeup
Thu 10:30 AM 07 22 01 Atlantis undocks from space station
Thu 04:29 PM 08 04 00 STS/ISS crew sleep begins
09/15/06
Fri 12:29 AM 08 12 00 STS crew wakeup
Fri 04:29 AM 08 16 00 OBSS survey begins
Fri 03:59 PM 09 03 30 Crew sleep begins
Fri 11:59 PM 09 11 30 Crew wakeup
09/16/06
Sat 02:34 AM 09 14 05 Cabin stow begins
Sat 03:49 AM 09 15 20 Flight control system checkout
Sat 04:59 AM 09 16 30 RCS hotfire
Sat 03:59 PM 10 03 30 Crew sleep begins
Sat 11:59 PM 10 11 30 Crew wakeup
09/17/06
Sun 02:59 AM 10 14 30 Deorbit timeline begins
Sun 07:00 AM 10 18 31 Deorbit ignition (orbit 171)
Sun 08:03 AM 10 19 34 Landing
09/18/06
Mon 12:08 AM Soyuz TMA-9 launch from Kazakhstan
EDT EVENT
__________________________________________________
Saturday
10:00:00 AM Begin 13-hour 34-minute hold
12:20:00 PM JSC flight control team on station
01:30:00 PM Communications system activation
02:00:00 PM Crew module voice checks
03:10:00 PM Flight crew equipment late stow
07:00:00 PM Rotating service structure moved to park position
09:00:00 PM Ascent switch list
11:34:00 PM Resume countdown
11:34:00 PM Terminate pad tours
11:49:00 PM APU bite test
11:54:00 PM Pad clear of non-essential personnel
Sunday
12:44:00 AM Fuel cell activation
01:34:00 AM MCC-Houston in launch comm configuration
02:04:00 AM Booster joint heater activation
02:34:00 AM Final fueling preps; launch area clear
04:34:00 AM Begin 2-hour built-in hold (T-minus 6 hours)
05:24:00 AM Mission management team tanking meeting
06:04:00 AM External tank ready for fueling
06:34:00 AM Resume countdown (T-minus 6 hours)
06:34:00 AM LO2, LH2 transfer line chilldown
06:44:00 AM Main propulsion system chill down
06:44:00 AM LH2 slow fill
07:04:00 AM LO2 slow fill
07:24:00 AM LO2 fast fill
07:34:00 AM LH2 fast fill
08:49:00 AM LH2 topping
09:29:00 AM LH2 replenish
09:34:00 AM LO2 replenish; fueling complete
09:34:00 AM Begin 3-hour built-in hold (T-minus 3 hours)
09:34:00 AM Closeout crew to white room
09:34:00 AM External tank in stable replenish mode
09:49:00 AM Astronaut support personnel comm checks
10:19:00 AM Pre-ingress switch reconfig
10:30:00 AM NASA television coverage begins
10:55:00 AM Astronaut breakfast photo op
12:00:00 PM Crew weather briefing
12:10:00 PM Astronauts don pressure suits
12:34:00 PM Resume countdown (T-minus 3 hours)
12:40:00 PM Crew departs O&C building
01:10:00 PM Crew ingress
01:59:00 PM Astronaut comm checks
02:24:00 PM Hatch closure
02:59:00 PM White room closeout
03:14:00 PM Begin 10-minute built-in hold (T-minus 20m)
03:16:00 PM NASA test director countdown briefing
03:24:00 PM Resume countdown (T-minus 20m)
03:25:00 PM Backup flight computer to OPS 1
03:29:00 PM KSC area clear to launch
03:35:00 PM Begin final built-in hold (T-minus 9m)
03:45:57 PM NTD launch status verification
04:20:57 PM Resume countdown (T-minus 9m)
04:22:27 PM Orbiter access arm retraction
04:24:00 PM Launch window opens (actual: 4:24:57 p.m.)
04:24:57 PM Hydraulic power system (APU) start
04:25:02 PM Terminate liquid oxygen replenish
04:25:57 PM Purge sequence 4 hydraulic test
04:25:57 PM Inertial measurement units to inertial
04:26:02 PM Aerosurface profile
04:26:27 PM Main engine steering test
04:27:02 PM Liquid oxygen tank pressurization
04:27:22 PM Fuel cells to internal reactants
04:27:27 PM Clear caution-and-warning memory
04:27:57 PM Crew closes visors
04:28:00 PM Liquid hydrogen tank pressurization
04:29:07 PM Booster joint heater deactivation
04:29:26 PM Shuttle computers take control of countdown
04:29:36 PM Booster steering test
04:29:50 PM Main engine start (T-6.6 seconds)
04:29:57 PM Booster ignition and liftoff
DATE/EDT.......DD...HH...MM...EVENT
08/27/06
Sun 04:30 PM...00...00...00...STS-115 Launch (flight day 1)
Sun 05:08 PM...00...00...38...OMS-2 rocket firing
Sun 07:00 PM...00...02...30...Post-insertion complete
Sun 07:05 PM...00...02...35...Group B computer powerdown
Sun 07:10 PM...00...02...40...Shuttle robot arm (SRMS) powerup
Sun 07:20 PM...00...02...50...Elevon park
Sun 07:25 PM...00...02...55...SRMS checkout
Sun 08:10 PM...00...03...40...SRMS powerdown
Sun 08:30 PM...00...04...00...Wing leading edge system activation
Sun 08:55 PM...00...04...25...ET video downlink
Sun 09:31 PM...00...05...01...NC-1 rendezvous rocket firing
Sun 10:30 PM...00...06...00...Crew sleep begins
The astronauts will spend their first few hours in space activating and checking out the shuttle's robot arm, downlinking data from the wing leading edge sensor system, photographing and downlinking pictures of the external tank and setting up a laptop computer network.
DATE/EDT.......DD...HH...MM...EVENT
08/28/06
Mon 06:30 AM...00...14...00...Crew wakeup
Mon 07:54 AM...00...15...25...NC2 rendezvous rocket firing
Mon 10:00 AM...00...17...30...SRMS/OBSS unberth
Mon 10:30 AM...00...18...00...Spacesuit checkout preps
Mon 11:00 AM...00...18...30...Spacesuit checkout
Mon 11:20 AM...00...18...50...Starboard wing survey
Mon 12:30 PM...00...20...00...Crew meals begin
Mon 12:50 PM...00...20...20...Nose cap survey
Mon 01:00 PM...00...20...30...OMS pod inspection
Mon 01:30 PM...00...21...00...EVA prep for transfer
Mon 03:20 PM...00...22...50...Port wing survey
Mon 03:30 PM...00...23...00...Transfer preps
Mon 04:50 PM...01...00...20...OBSS berthing
Mon 05:25 PM...01...00...55...Upper surface survey
Mon 06:25 PM...01...01...55...LDRI laser checkout
Mon 06:25 PM...01...01...55...Rendezvous tools checkout
Mon 06:30 PM...01...02...00...Centerline camera installation
Mon 07:00 PM...01...02...30...Orbiter docking system ring extension
Mon 07:35 PM...01...03...05...NC3 rendezvous rocket firing
Mon 09:30 PM...01...05...00...Crew sleep begins
That will set the stage for five action-packed days of work to dock with the space station and attach the new solar arrays.
DATE/EDT.......DD...HH...MM...EVENT
08/29/06
Tue 05:30 AM...01...13...00...STS/ISS crew wakeup
Tue 07:15 AM...01...14...45...Group B computer powerup
Tue 07:30 AM...01...15...00...Rendezvous timeline begins
Tue 08:19 AM...01...15...49...NC4 rendezvous rocket firing
Tue 09:51 AM...01...17...21...TI rendezvous rocket firing
Tue 10:00 AM...01...17...30...ISS: Verify RPM photo setup ready
Tue 11:15 AM...01...18...45...Begin final approach
Tue 11:35 AM...01...19...05...Rendezvous pitch maneuver
Tue 12:38 PM...01...20...08...Atlantis docks with space station
Tue 01:00 PM...01...20...30...Hatch leak checks
Tue 01:15 PM...01...20...45...Group B computer powerdown
Tue 01:30 PM...01...21...00...ODS preps for entry
Tue 01:50 PM...01...21...20...Hatches opened
Tue 02:00 PM...01...21...30...SRMS P3/P4 grapple
Tue 02:15 PM...01...21...45...Welcome aboard!
Tue 02:25 PM...01...21...55...Safety briefing
Tue 02:50 PM...01...22...20...SSRMS configured
Tue 02:50 PM...01...22...20...Post-docking EVA transfer
Tue 03:20 PM...01...22...50...SRMS unberths P3/4
Tue 03:25 PM...01...22...55...REBA checkout
Tue 04:10 PM...01...23...40...EVA tools configured
Tue 04:40 PM...02...00...10...SRMS hands P3/P4 to SSRMS
Tue 05:00 PM...02...00...30...SRMS ungrapples P3/4
Tue 05:25 PM...02...00...55...EVA camera setup
Tue 05:50 PM...02...01...20...EVA-1: Procedures review
Tue 07:55 PM...02...03...25...EVA-1: EV1, EV2 campout prebreathe
Tue 08:40 PM...02...04...10...EVA-1: 10.2 depress
Tue 09:00 PM...02...04...30...ISS crew sleep begins
Tue 09:30 PM...02...05...00...STS crew sleep begins (EV1/EV2 in airlock)
"Traditionally, space shuttle crews have kind of taken the day off after docking," Ferguson said in a NASA interview. "It's typically a very long and very busy day. They might do some general transfer operations after docking, but they would kind of pause and take the night off and begin the heavy construction the next day.
DATE/EDT.......DD...HH...MM...EVENT
08/30/06
Wed 05:30 AM...02...13...00...STS/ISS crew wakeup
Wed 06:00 AM...02...13...30...EVA-1: Hygiene break; prebreathe
Wed 06:15 AM...02...13...45...EVA-1: Airlock repress
Wed 06:45 AM...02...14...15...EVA-1: 10.2 depress
Wed 07:20 AM...02...14...50...EVA-1: Campout EVA preps
Wed 07:20 AM...02...14...50...SSRMS moves P3/4 to pre-install position
Wed 08:40 AM...02...16...10...SSRMS maneuver to latch position
Wed 08:50 AM...02...16...20...EVA-1: Spacesuit prebreathe
Wed 09:10 AM...02...16...40...P1/P3 bolts engaged
Wed 09:55 AM...02...17...25...EVA-1: Crew lock depressurization
Wed 10:10 AM...02...17...40...SSRMS ungrapple
Wed 10:30 AM...02...18...00...EVA-1: Airlock egress; tool setup
Wed 11:05 AM...02...18...35...EVA-1: EV1: Connect P1/P3 lower cable tray
Wed 11:05 AM...02...18...35...EVA-1: EV2: Release aft SA blanket box restraint
Wed 12:05 PM...02...19...35...EVA-1: EV1: Release aft BGA restraint
Wed 12:05 PM...02...19...35...EVA-1: EV2: Release forward SA blanket box restraint
Wed 12:30 PM...02...20...00...ISS: EVA-2 tools configured
Wed 12:50 PM...02...20...20...EVA-1: EV1: Solar alpha rotary joint prep
Wed 01:00 PM...02...20...30...EVA-1: EV1: Unstow aft SA blanket box restraint
Wed 01:05 PM...02...20...35...EVA-1: EV2: Release forward BGA restraint
Wed 01:30 PM...02...21...00...EVA-1: EV1: SARJ preps
Wed 01:50 PM...02...21...20...EVA-1: EV2: Unstow forward SA blanket box
Wed 02:05 PM...02...21...35...EVA-1: EV1: Connect P1/P3 upper cable tray
Wed 02:20 PM...02...21...50...EVA-1: EV2: SARJ prep
Wed 03:20 PM...02...22...50...EVA-1: EV1: SARJ prep
Wed 04:10 PM...02...23...40...EVA-1: Cleanup
Wed 04:50 PM...03...00...20...EVA-1: Airlock ingress/repress
Wed 06:40 PM...03...02...10...EVA-2: Procedures review
Wed 07:55 PM...03...03...25...EVA-2: EV3/EV4 campout mask prebreathe
Wed 08:40 PM...03...04...10...EVA-2: Crew lock to 10.2 psi
Wed 09:00 PM...03...04...30...ISS crew sleep begins
Wed 09:30 PM...03...05...00...STS crew sleep begins (EV3/EV4 in airlock)
"On EVA 1 we start getting the P3/P4 element ready for solar array deploy," Piper said in a NASA interview. "That happens two days later. The first task [for] that is to hook up the umbilicals. Those are just the power cables and data cables so that the ground can start commanding all of the, the MDMs, the boxes that are on the elements and getting them ready for deploy. Actually one of Joe's tasks is to hook up the umbilicals.
DATE/EDT.......DD...HH...MM...EVENT
08/31/06
Thu 05:30 AM...03...13...00...STS/ISS crew wakeup
Thu 06:00 AM...03...13...30...EVA-2: Hygiene break/prebreathe
Thu 06:15 AM...03...13...45...EVA-2: Crew lock repress
Thu 06:45 AM...03...14...15...EVA-2: Crew lock depress to 10.2 psi
Thu 07:20 AM...03...14...50...EVA-2: Campout EVA prep
Thu 08:50 AM...03...16...20...EVA-2: EMU purge
Thu 09:05 AM...03...16...35...EVA-2: EMU prebreathe
Thu 09:55 AM...03...17...25...EVA-2: Crew lock depressurization
Thu 10:30 AM...03...18...00...EVA-2: Airlock egress; setup
Thu 10:55 AM...03...18...25...SSRMS camera viewing
Thu 11:10 AM...03...18...40...EVA-2: EV3: Remove aft sequential shunt unit shroud
Thu 11:10 AM...03...18...40...EVA-2: EV4: SARJ prep
Thu 11:10 AM...03...18...40...EVA-2: EV3: SARJ prep
Thu 01:25 PM...03...20...55...ISS: Transfer operations
Thu 03:40 PM...03...23...10...EVA-2: Deploy SARJ brace
Thu 04:10 PM...03...23...40...EVA-2: Payload bay cleanup, airlock ingress
Thu 04:30 PM...04...00...00...MCC: SA/SARJ activation/checkout begins
Thu 04:30 PM...04...00...00...Transfer tagup
Thu 04:30 PM...04...00...00...EVA-2: Airlock ingress
Thu 04:50 PM...04...00...20...EVA-2: Airlock repressurization
Thu 06:30 PM...04...02...00...12A EMU swap EVA-2
Thu 09:00 PM...04...04...30...ISS crew sleep begins
Thu 09:30 PM...04...05...00...STS crew sleep begins
Burbank's call sign is EV-3 and MacLean is EV-4. Burbank's suit features horizontal red dashes while MacLean's sports diagonal dashes.
DATE/EDT.......DD...HH...MM...EVENT
09/01/06
Fri 12:25 AM...04...07...55...MCC: 4A mast deploy (1 section)
Fri 01:55 AM...04...09...25...MCC: 2A mast deploy (1 section)
Fri 05:30 AM...04...13...00...STS/ISS crew wakeup
Fri 07:00 AM...04...14...30...SSRMS reconfig
Fri 09:05 AM...04...16...35...STS: 4A mast deploy to 49 percent
Fri 09:45 AM...04...17...15...STS: 4A mast deploy to 100 percent
Fri 10:45 AM...04...18...15...STS: 2A mast deploy to 49 percent
Fri 11:25 AM...04...18...55...STS: 2A mast deploy to 100 percent
Fri 01:00 PM...04...20...30...Crew meals begin
Fri 02:00 PM...04...21...30...SSRMS walk off reconfig
Fri 02:20 PM...04...21...50...SSRMS double walk off to lab
Fri 02:25 PM...04...21...55...Spacesuit servicing
Fri 04:30 PM...05...00...00...PAO event (STS CDR, ISS CDR, FE-2)
Fri 04:30 PM...05...00...00...EVA tool config
Fri 05:00 PM...05...00...30...Transfer tagup
Fri 05:05 PM...05...00...35...PAO event (STS CDR, MS-4)
Fri 05:05 PM...05...00...35...Infrared camera setup
Fri 05:25 PM...05...00...55...EVA-3: Procedures review
Fri 07:55 PM...05...03...25...EVA-3: Campout mask pre-breathe
Fri 08:40 PM...05...04...10...EVA-3: Crew lock 10.2 depress
Fri 09:00 PM...05...04...30...ISS crew sleep begins
Fri 09:30 PM...05...05...00...STS crew sleep begins (EV1/EV2 in airlock)
"A lot of times we get a lot of credit for doing the grand visual activities, but overnight the mission control center is going to be extremely busy," Ferguson said. "They're going to be doing a lot of what's called SARJ checkout that evening. They'll rotate the alpha joint 180 degrees. Essentially we're going to flip the whole package upside down so the radiator is now pointed nadir, towards the Earth. They are going to unlock the blanket boxes. The blanket boxes are the rigid covers which cover the solar arrays. They're going to do a lot of the preparation activities so that when we come out on the next flight day, we'll be ready to unfurl the solar arrays.
DATE/EDT.......DD...HH...MM...EVENT
09/02/06
Sat 05:30 AM...05...13...00...STS/ISS crew wakeup
Sat 06:00 AM...05...13...30...EVA-3: Hygiene break/pre-breathe
Sat 06:15 AM...05...13...45...EVA-3: Crew lock repress
Sat 06:45 AM...05...14...15...EVA-3: Crew lock depress to 10.2 psi
Sat 07:20 AM...05...14...50...EVA-3: Campout EVA prep
Sat 08:50 AM...05...16...20...EVA-3: EMU purge
Sat 09:05 AM...05...16...35...EVA-3: EMU pre-breathe
Sat 09:55 AM...05...17...25...EVA-3: Crew lock depressurization
Sat 10:30 AM...05...18...00...EVA-3: Airlock egress/setup
Sat 10:45 AM...05...18...15...EVA-3: EV1: EVA-P6 BGA installation
Sat 10:45 AM...05...18...15...EVA-3: EV2: S-band sub assembly antenna R&R prep
Sat 11:15 AM...05...18...45...EVA-3: EV2: Release CNCH/WNCH
Sat 11:40 AM...05...19...10...EVA-3: EV1: Release CNCH/WNCH
Sat 12:05 PM...05...19...35...PV radiator deploy (CDR, PLT)
Sat 12:05 PM...05...19...35...EVA-3: Remove and stow P3 keel pin
Sat 12:50 PM...05...20...20...EVA-3: P3 cleanup
Sat 01:35 PM...05...21...05...EVA-3: SASA R&R
Sat 03:25 PM...05...22...55...EVA-3: EV2: S-band BSP and transponder R&R
Sat 03:35 PM...05...23...05...EVA-3: EV1: S-band gimbal installation
Sat 03:55 PM...05...23...25...EVA-3: EV1: MISSE 5
Sat 04:30 PM...06...00...00...EVA-3: Cleanup
Sat 04:50 PM...06...00...20...EVA-3: Airlock ingress
Sat 04:55 PM...06...00...25...EVA-3: Airlock repressurization
Sat 05:05 PM...06...00...35...Post-EVA spacesuit servicing
Sat 07:00 PM...06...02...30...BSA init
Sat 09:00 PM...06...04...30...ISS crew sleep begins
Sat 09:30 PM...06...05...00...STS crew sleep begins
"EVA 3 is a cleanup of P3 primarily, to prepare it for future missions," Tanner said in a NASA interview. "We need to clear the rails, the path for the mobile transporter to get out to what we refer to as work site 8 so that 12A.1 (the next shuttle crew) can install P5 on the end of P4. So there are things that we need to remove - a keel pin and drag link are the biggest of those."
DATE/EDT.......DD...HH...MM...EVENT
09/03/06
Sun 05:30 AM...06...13...00...STS/ISS crew wakeup
Sun 08:30 AM...06...16...00...STS crew off duty time begins
Sun 12:30 PM...06...20...00...Joint crew photo
Sun 12:50 PM...06...20...20...Joint crew news conference
Sun 01:25 PM...06...20...55...Joint crew meal
Sun 02:35 PM...06...22...05...PAO event (STS CDR, MS1, MS2, MS3, MS4)
Sun 02:25 PM...06...21...55...Transfers continue
Sun 03:30 PM...06...23...00...EVA prep for shuttle transfer
Sun 06:35 PM...07...02...05...Transfer tagup
Sun 09:00 PM...07...04...30...ISS crew sleep begins
Sun 09:30 PM...07...05...00...STS crew sleep begins
The original flight plan called for the shuttle crew to unlimber Atlantis' robot arm before leaving the station to begin another heat shield inspection, this one to look for signs of damage from orbital debris that might have occurred since the first inspection on flight day two. But based on feedback from Discovery's crew, Jett decided to defer the so-called late inspection until after Atlantis undocks.
DATE/EDT.......DD...HH...MM...EVENT
09/04/06
Mon 05:30 AM...07...13...00...STS/ISS crew wakeup
Mon 07:45 AM...07...15...15...Transfers resume
Mon 08:40 AM...07...16...10...Rendezvous tools checkout
Mon 09:45 AM...07...17...15...O2 transfer hardware tear down
Mon 10:15 AM...07...17...45...Transfer tagup
Mon 10:40 AM...07...18...10...Joint crew meal
Mon 11:40 AM...07...19...10...Farewell ceremony
Mon 11:55 AM...07...19...25...Hatch closure
Mon 12:25 PM...07...19...55...Centerline camera installation
Mon 12:25 PM...07...19...55...ODS leak check
Mon 01:10 PM...07...20...40...Spacesuit installation
Mon 01:10 PM...07...20...40...Group B computer powerup
Mon 01:40 PM...07...21...10...Undocking timeline begins
Mon 02:31 PM...07...22...01...Atlantis undocks from space station
Mon 03:40 PM...07...23...10...PMA-2 depressurization
Mon 03:46 PM...07...23...16...Separation burn No. 1
Mon 04:14 PM...07...23...44...Separation burn No. 2
Mon 04:15 PM...07...23...45...Group B computer powerdown
Mon 04:45 PM...08...00...15...Undocking videotape replay
Mon 05:30 PM...08...01...00...NC-5 rocket firing
Mon 08:30 PM...08...04...00...STS/ISS crew sleep begins
After the fly around is complete, Atlantis will drop back about 40 miles for the late inspection the next day. If problems are found, the shuttle will have enough fuel on board to re-dock with the space station. But engineers are hopeful no such repair work will be required.
DATE/EDT.......DD...HH...MM...EVENT
09/05/06
Tue 04:30 AM...08...12...00...STS crew wakeup
Tue 07:30 AM...08...15...00...NC-6 rocket firing
Tue 07:30 AM...08...15...00...OBSS unberth
Tue 08:30 AM...08...16...00...OBSS starboard wing leading edge survey
Tue 09:35 AM...08...17...05...Cabin stow begins
Tue 10:00 AM...08...17...30...OBSS nose cap survey
Tue 11:30 AM...08...19...00...Crew meal
Tue 12:30 PM...08...20...00...OBSS port wing leading edge survey
Tue 02:00 PM...08...21...30...OBSS berthing
Tue 02:35 PM...08...22...05...SRMS berthing
Tue 03:30 PM...08...23...00...LDRI downlink
Tue 06:35 PM...09...02...05...NC-7 rocket firing
Tue 08:00 PM...09...03...30...Crew sleep begins
With the late inspection complete, the astronauts will focus on rigging Atlantis for re-entry and landing, spending the next day packing up, tearing down the laptop computer network and testing the shuttle's hydraulic and steering systems. If all goes well, Jett will guide Atlantis to a landing back at the Kennedy Space Center a few minutes past noon on Sept. 7.
DATE/EDT.......DD...HH...MM...EVENT
09/06/06
Wed 04:00 AM...09...11...30...Crew wakeup
Wed 06:35 AM...09...14...05...Cabin stow begins
Wed 07:33 AM...09...15...03...NC-8 rocket firing
Wed 07:50 AM...09...15...20...Flight control system checkout
Wed 09:00 AM...09...16...30...RCS hotfire
Wed 10:40 AM...09...18...10...Deorbit review
Wed 11:10 AM...09...18...40...Crew meal
Wed 12:10 PM...09...19...40...PAO event (entire crew)
Wed 12:30 PM...09...20...00...Crew off duty time begins
Wed 02:30 PM...09...22...00...Entry video setup
Wed 03:30 PM...09...23...00...CDR, PLT PILOT landing practice
Wed 04:10 PM...09...23...40...Laptop computer teardown (part 1)
Wed 04:15 PM...09...23...45...Ergometer stow
Wed 04:45 PM...10...00...15...Ku-band antenna stow
Wed 05:25 PM...10...00...55...NC-9 rocket firing
Wed 08:00 PM...10...03...30...Crew sleep begins
09/07/06
Thu 04:00 AM...10...11...30...Crew wakeup
Thu 05:55 AM...10...13...25...Group B powerup
Thu 06:10 AM...10...13...40...Navigation system alignment
Thu 06:35 AM...10...14...05...Laptop computer teardown (part 2)
Thu 06:45 AM...10...14...15...OCAC, GIRA stow
"We've gone through a very difficult period in the last three-and-a-half years," Tanner said. "We had to fix a few things, and I think we had to develop tools that gave us some repair capability and some backup capability. We needed to understand some things that we weren't maybe paying enough attention to before.
08/27/06
Sun 04:30 PM...00...00...00...STS-115 Launch
Sun 05:30 PM...00...01...00...Post-launch news conference
Sun 09:30 PM...00...05...00...Ascent imagery briefing
Sun 10:30 PM...00...06...00...Crew sleep begins
08/28/06
Mon 06:30 AM...00...14...00...Crew wakeup
Mon 11:20 AM...00...18...50...Wing leading edge/nose cap survey begins
Mon 03:00 PM...00...22...30...Mission status briefing
Mon 06:00 PM...01...01...30...Post-MMT briefing
Mon 09:30 PM...01...05...00...Crew sleep begins
08/29/06
Tue 05:30 AM...01...13...00...STS crew wakeup
Tue 12:38 PM...01...20...08...Atlantis docks with space station
Tue 03:00 PM...01...22...30...Mission status briefing
Tue 03:20 PM...01...22...50...Solar array truss unberthed
Tue 06:00 PM...02...01...30...Post-MMT briefing
Tue 09:30 PM...02...05...00...Crew sleep begins
08/30/06
Wed 05:30 AM...02...13...00...Crew wakeup
Wed 09:10 AM...02...16...40...P1/P3 bolts engaged
Wed 10:30 AM...02...18...00...EVA-1 begins
Wed 04:50 PM...03...00...20...EVA-1 ends
Wed 06:00 PM...03...01...30...Mission status/MMT briefing
Wed 09:30 PM...03...05...00...Crew sleep begins
08/31/06
Thu 05:30 AM...03...13...00...Crew wakeup
Thu 10:30 AM...03...18...00...EVA-2 begins
Thu 04:50 PM...04...00...20...EVA-2 ends
Thu 06:00 PM...04...01...30...Mission status/MMT briefing
Thu 09:30 PM...04...05...00...Crew sleep begins
09/01/06
Fri 02:45 AM...04...10...15...MCC solar array deploy (1 bay each)
Fri 05:30 AM...04...13...00...Crew wakeup
Fri 09:05 AM...04...16...35...STS: 4A mast deploy to 49 percent
Fri 09:45 AM...04...17...15...STS: 4A mast deploy to 100 percent
Fri 10:45 AM...04...18...15...STS: 2A mast deploy to 49 percent
Fri 11:25 AM...04...18...55...STS: 2A mast deploy to 100 percent
Fri 02:00 PM...04...21...30...Mission status briefing
Fri 04:30 PM...05...00...00...PAO event (Jett, Vinogradov, Reiter)
Fri 05:05 PM...05...00...35...PAO event (Jett, MacLean)
Fri 06:00 PM...05...01...30...Post-MMT briefing
Fri 09:30 PM...05...05...00...Crew sleep begins
09/02/06
Sat 05:30 AM...05...13...00...Crew wakeup
Sat 10:30 AM...05...18...00...EVA-3 begins
Sat 04:50 PM...06...00...20...EVA-3 ends
Sat 06:00 PM...06...01...30...Mission status briefing
Sat 09:30 PM...06...05...00...Crew sleep begins
09/03/06
Sun 05:30 AM...06...13...00...Crew wakeup
Sun 08:30 AM...06...16...00...STS crew off duty time begins
Sun 12:50 PM...06...20...20...Joint crew news conference
Sun 02:35 PM...06...22...05...PAO event (5 crew members)
Sun 03:00 PM...06...22...30...Mission status briefing
Sun 09:30 PM...07...05...00...Crew sleep begins
09/04/06
Mon 05:30 AM...07...13...00...Crew wakeup
Mon 02:29 PM...07...21...59...Atlantis undocks from space station
Mon 05:00 PM...07...00...30...Mission status briefing
Mon 08:30 PM...08...04...00...Crew sleep begins
09/05/06
Tue 04:30 AM...08...12...00...Crew wakeup
Tue 08:30 AM...08...16...00...Wing leading edge/nose cap survey
Tue 02:00 PM...08...21...30...Mission status briefing
Tue 08:00 PM...09...03...30...Crew sleep begins
09/06/06
Wed 04:00 AM...09...11...30...Crew wakeup
Wed 12:10 PM...09...19...40...PAO event (entire crew)
Wed 01:30 PM...09...21...00...Mission status briefing
Wed 05:00 PM...10...00...30...Post-MMT briefing
Wed 08:00 PM...10...03...30...Crew sleep begins
09/07/06
Thu 04:00 AM...10...11...30...Crew wakeup
Thu 11:00 AM...10...18...30...Deorbit ignition (orbit 171)
Thu 12:02 PM...10...19...32...Landing at Kennedy Space Center
DAY/EDT........DD...HH...MM...EVENT
Sat 04:52 PM...00...00...00...STS-115 Launch
Mon 12:13 PM...01...19...21...Atlantis docks with space station
Tue 10:52 AM...02...18...00...EVA-1 begins
Tue 05:17 PM...03...00...25...EVA-1 ends
Wed 10:52 AM...03...18...00...EVA-2 begins
Wed 05:22 PM...04...00...30...EVA-2 ends
Thu 08:12 AM...04...15...20...4A solar array mast deploy to 100 percent
Thu 09:42 AM...04...16...50...2A solar array mast deploy to 100 percent
Fri 10:52 AM...05...18...00...EVA-3 begins
Fri 05:17 PM...06...00...25...EVA-3 ends
Sun 02:06 PM...07...21...14...Undocking
Wed 10:36 AM...10...17...44...Deorbit ignition (orbit 170)
Wed 11:38 AM...10...18...46...Landing
Sun 04:30 PM...00...00...00...STS-115 Launch (flight day 1)
Tue 12:38 PM...01...20...08...Atlantis docks with space station
Wed 10:30 AM...02...18...00...EVA-1 begins
Wed 04:55 PM...03...00...25...EVA-1 ends
Thu 10:30 AM...03...18...00...EVA-2 begins
Thu 05:00 PM...04...00...30...EVA-2 ends
Fri 07:50 AM...04...15...20...4A solar array mast deploy to 100 percent
Fri 09:20 AM...04...16...50...2A solar array mast deploy to 100 percent
Sat 10:30 AM...05...18...00...EVA-3 begins
Sat 04:55 PM...06...00...25...EVA-3 ends
Mon 02:29 PM...07...21...59...Undocking
Thu 11:00 AM...10...18...30...Deorbit ignition (orbit 171)
Thu 12:02 PM...10...19...32...Landing
NASA managers are expected to discuss launch date targets later this week at a program requirements change board - PRCB - meeting. An official launch date will be announced Aug. 16 at the conclusion of a two-day flight readiness review.
The CBS News Shuttle Status and Quick-Look pages have been updated to cover NASA's next shuttle mission, STS-115. The flight plan, a flight plan walk through, launch windows, crew assignments/seating, mission personnel and other useful data are now on line:
http://www.cbsnews.com/network/news/space/current.html
http://www.cbsnews.com/network/news/space/currentglance.html
The shuttle Atlantis will be moved from its Orbiter Processing Facility hangar to the Vehicle Assembly Building Monday for attachment to an external fuel tank and booster rockets. Rollout to launch pad 39B is targeted for July 31 for a launch attempt Aug. 27 or 28.
DATE EVENT
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07/24/06 STS-115: Atlantis rollover from OPF to VAB
07/27/06 STS-115: Payload to launch pad
07/31/06 STS-115: Shuttle stack rollout to launch pad
08/03/06 ISS: Spacewalk (Reiter and Williams)
08/07/06 STS-115: Crew flies to Kennedy Space Center
08/08/06 STS-115: Terminal Countdown Demonstration Test begins
08/09/06 STS-115: Crew Q & A at launch pad
08/10/08 STS-115: TCDT ends with simulated countdown
08/11/06 STS-115: Pre-flight briefings at the Johnson Space Center
08/15/06 STS-115: Flight readiness review begins
08/16/06 STS-115: FRR ends; official launch date announced
08/24/06* STS-115: Countdown begins
08/27/06* STS-115: Launch
* If ET separation lighting permits an 8/27 launch
The goal of mission STS-115 is to attach a huge set of solar arrays to the left side of the space station's main solar array truss (Boeing payload description).
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