The shuttle Discovery banks to line up on runway 22 at
Edwards Air Force Base. (Photo: NASA TV)
By William Harwood
CBS News/Kennedy Space Center
The following copy originally was posted on the Current Mission space page at http://cbsnews.com/network/news/space/current.html. Comments, suggestions and corrections welcome!
TABLE OF CONTENTS
09:10 PM, 9/11/09: Shuttle Discovery lands in California (UPDATED at 11:15 p.m. with crew comments)
The shuttle Discovery dropped out of orbit and swooped to a flawless California landing Friday to close out a successful space station resupply mission.
Shuttle commander Frederick "C.J." Sturckow and pilot Kevin Ford fired the shuttle's twin braking rockets at 7:47:37 p.m. EDT to drop the ship out of orbit for an hourlong descent to Edwards Air Force Base.
The shuttle Discovery banks to line up on runway 22 at
Edwards Air Force Base. (Photo: NASA TV)
After a steep descent across the Los Angeles basin, Sturckow took over manual control at an altitude of about 50,000 feet above the Mojave Desert landing site and guided the spaceplane through a sweeping 213-degree right overhead turn to line up on runway 22.
As Sturckow pulled the shuttle's nose up just before touchdown, Ford deployed the ship's three main landing gear and the spaceplane settled to a tire-smoking touchdown at 8:53:25 p.m.
"Houston, Discovery, wheels stopped," Sturckow radioed a few moments later as Discovery rolled to a holt.
"Copy, wheels stopped," replied astronaut Eric Boe in mission control at the Johnson Space Center in Houston. "Welcome home, Discovery. Congratulations on an extremely successful mission, stepping up science to a new level on the International Space Station."
Discovery, seconds from touchdown. (Photo: NASA TV)
Mission duration was 13 days 20 hours 53 minutes and 45 seconds for a voyage spanning 5.7 million miles and 219 complete orbits since blastoff from launch complex 39A at the Kennedy Space Center on Aug. 28 at 11:59:37 p.m.
Sturckow, Ford and four of their five crewmates - flight engineer Jose Hernandez, Patrick Forrester, John "Danny" Olivas and European Space Agency astronaut Christer Fuglesang - doffed their pressure suits for a traditional walk-around inspection about an hour-and-a-half after landing.
"Well, the crew of STS-128 and the space shuttle Discovery, we're very happy to be back on land here in California," Sturckow said on the runway. "We wish we could have gone to Florida today, gotten to see our families down there, but it just didn't work out with the weather."
Discovery's seventh crewmember, returning space station flight engineer Timothy Kopra, made the trip to Earth strapped into a recumbent seat on the shuttle's lower deck to ease his transition back to gravity after 58 days in space.
Asked if he planned to walk off the shuttle under his own power, Kopra told CBS News earlier this week "there are some scientific experiments that require me to come off horizontally, so I won't even have the opportunity to test it out."
Discovery rolls down runway 22. (Photo: NASA TV)
Like all space station crew members, Kopra exercised daily and "we have the chance to do the absolute best we can to stay in good shape. I think there may be some effects, but hopefully I'll recover quickly."
Reflecting on his stay in orbit during a news conference last week, Kopra said "this experience has completely exceeded anything that I thought it would be like, just the sights, the sounds, the experiences with a great crew and really being part of two shuttle missions. It's been absolutely phenomenal.
"The main thing, obviously, I'm looking forward to is seeing my family again, my wife and two kids. And maybe have a sip of a beer once I get home."
Kopra and his shuttle crewmates plan to fly back to Houston on Saturday for reunions with friends and family members and debriefings with mission managers and engineers.
Discovery delivered some nine tons of supplies and equipment to the International Space Station along with Kopra's replacement, astronaut Nicole Stott.
Over the course of a week of docked operations, the astronauts transferred two science racks, an experiment sample freezer, a new treadmill, an astronaut sleep station, a carbon dioxide removal assembly and other supplies and equipment to the space station.
"Wheels stopped." (Photo: NASA TV)
In addition, the shuttle crew carried out three spacewalks to replace a massive ammonia coolant tank, retrieve two external experiments, deploy a spare parts mounting mechanism and string power and data cables needed for a new module that will be attached next year.
Discovery undocked from the station Tuesday to prepare for landing. The astronauts intended to land Thursday at the Kennedy Space Center, but stormy weather blocked both available landing opportunities and entry Flight Director Richard Jones told them to stay in orbit an extra day.
More of the same developed today and after waving off the first Florida opportunity, Jones threw in the towel and diverted Sturckow and company to Edwards. It will take a week to 10 days to prepare the shuttle for a ferry flight back to Florida.
"Discovery was a really great vehicle on this mission, it performed flawlessly," Sturckow said after landing. "It was a great mission, we're looking forward to getting back to Houston for the debriefs. We just want to thank everybody for their support."
Next up for NASA is launch of the shuttle Atlantis around Nov. 9 on a mission to mount critical spare parts on the station as a hedge against future failures after the shuttle fleet is retired next year.
Aboard the space station, meanwhile, the Expedition 20 crew is moving into a particularly busy phase of flight. A new Japanese cargo ship, launched from Japan on Thursday, is scheduled to arrive next week. At the end of the month, a Russian Soyuz spacecraft is scheduled for launch to carry two new crew members - Jeffrey Williams and Maxim Suraev - to the station.
Williams and Suraev will be joined for launch by Cirque du Soleil founder Guy Laliberte, a billionaire space tourist who is believed to have paid around $35 million for a ride to the station.
Laliberte will return to Earth Oct. 11 with outgoing space station commander Gennady Padalka and flight engineer Michael Barratt.
7:50 PM, 9/11/09: Shuttle braking rockets fired
Shuttle commander Frederick Sturckow and pilot Kevin Ford fired the shuttle Discovery's twin braking rockets at 7:47:37 p.m. EDT for two minutes and 35 seconds, slowing the ship by about 182 mph to drop it out of orbit for a planned landing at Edwards Air Force Base, Calif.
If all goes well, Sturckow will guide the shuttle to a touchdown on runway 22 around 8:53:34 p.m. to close out a successful space station assembly mission. This status report will be updated after landing or as conditions warrant.
3:55 PM, 9/11/09: Discovery diverted to Edwards Air Force Base
With stormy weather in Florida and forecasts calling for more of the same Saturday, entry Flight Director Richard Jones waved off a second opportunity for the shuttle Discovery to land in Florida today and instead diverted the crew to California's Edwards Air Force Base. Landing is expected around 8:53 p.m. EDT.
The decision to bypass Florida came after an initial landing opportunity was ruled out due to showers and cloud cover at the Kennedy Space Center. Flight controllers did not immediately rule out a landing one orbit later, but conditions continued to worsen and Jones called it off shortly before 4 p.m.
"Unfortunately, at KSC the weather has not improved, so we're going to wave off the second attempt," astronaut Eric Boe radioed from mission control in Houston. "So our next attempt is going to be at Edwards. The weather there at Edwards looks good, scattered (clouds) at 10,000 (feet), broken at 25 (thousand feet), winds right now, they're calling at 230 (degrees) eight (knots) peak 12, so it's an 11-knot headwind. ... That's about an hour before sunset."
"OK, we copy all Houston," commander Frederick Sturckow replied from the shuttle. "And we do appreciate everybody that worked the weather so hard in Florida and we appreciate the families making the trip down, but it just doesn't look like it's going to work out for today. So we'll set up for Edwards."
Sturckow and pilot Kevin Ford plan to fire Discovery's twin braking rockets for two minutes and 38 seconds starting at 7:47:37 p.m., slowing the ship by 182 mph and dropping the far side of its orbit into the atmosphere.
After a half-hour freefall, Discovery will enter the discernible atmosphere at an altitude of about 76 miles above the south Pacific Ocean. Approaching Edwards from the southwest, Discovery was expected to descend across the Los Angeles basin and out over the Mojave Desert before a 207-degree right overhead turn to line up on runway 22. Touchdown was targeted for 8:53:34 p.m. EDT.
A second California landing opportunity is available one orbit later at 10:28:21 p.m. Here are timelines for both opportunities (in EDT; times subject to minor changes):
Rev. 219 Deorbit to EDW Deorbit burn: 07:47:37 PM Change in velocity: 182 mph Burn Duration: 2:38 Crossrange: 429 sm Range to EDW from EI: 5,061 sm Turn: 207-degree left turn Runway: EDW 22 Landing: 08:53:34 PM EOM miles flown: 5.8 million 07:27 PM......MCC 'go' for deorbit burn 07:33 PM......MS seat ingress 07:42 PM......Single APU start 07:47:37 PM...Deorbit ignition 07:50:15 PM...Deorbit burn complete 08:22:03 PM...Entry interface 08:27:03 PM...1st roll command to left 08:38:09 PM...1st left-to-right roll reversal 08:40:34 PM...C-band radar acquisition 08:47:18 PM...Velocity less than mach 2.5 08:49:30 PM...Velocity less than mach 1 08:50:25 PM...207 degree right turn to runway 22 08:53:34 PM...Landing ----------------------- Rev. 220 Deorbit to EDW Deorbit burn: 09:23:37 PM Change in velocity: 183 mph Burn Duration: 2:39 Crossrange: 452 sm Range to EDW from EI: 5,038 sm Turn: 185-degree left turn Runway: EDW 22 Landing: 10:28:21 PM EOM miles flown: 5.8 million 09:03 PM......MCC 'go' for deorbit burn 09:09 PM......MS seat ingress 09:18 PM......Single APU start 09:23:37 PM...Deorbit ignition 09:26:16 PM...Deorbit burn complete 09:56:56 PM...Entry interface 10:01:53 PM...1st roll command to right 10:12:59 PM...1st right-to-left roll reversal 10:15:21 PM...C-band radar acquisition 10:22:07 PM...Velocity less than mach 2.5 10:24:19 PM...Velocity less than mach 1 10:25:24 PM...185-degree right turn to runway 22 10:28:21 PM...Landing
2:10 PM, 9/11/09: NASA waves off first Florida landing opportunity
With a "no-go" forecast, entry Flight Director Richard Jones has ruled out the first of the shuttle Discovery's two opportunities to land in Florida today. While the second opportunity is still in play, the forecast is not favorable, raising the likelihood of a diversion to Edwards Air Force Base, Calif., later this evening.
"We're observed no-go, forecast no-go for the rain showers within 30 miles," astronaut Eric Boe radioed the shuttle crew from mission control in Houston. "Weather is basically as we predicted, the atmosphere is unstable, so we're going to look at the second opportunity for KSC after this. We'll get you some words here shortly."
"OK. Any improvement in the forecast for the second opportunity?" asked Discovery commander Frederick Sturckow.
"No, the second opportunity looks about the same," Boe replied.
Here are the remaining deorbit opportunities for the Kennedy Space Center and Edwards Air Force Base (in EDT; see the 10:30 a.m. status report for detailed entry timelines):
. ORBIT......DEORBIT.........LANDING.........SITE 09/11 218........06:17:37 PM.....07:23:36 PM.....Kennedy Space Center 219........07:47:37 PM.....08:53:34 PM.....Edwards Air Force Base 220........09:23:37 PM.....10:28:21 PM.....Edwards Air Force Base
Sturckow and his crewmates now have one landing opportunity in Florida and two at Edwards Air Force Base, Calif. See the 10:30 a.m. status report for entry timelines for all three opportunities.
10:30 AM, 9/11/09: Astronauts prepare for delayed re-entry
Delayed one day by unstable weather in Florida, the Discovery astronauts are preparing the shuttle for another landing try today, on one coast or the other, to close out a busy space station resupply mission.
The crew has two landing opportunities at the Kennedy Space Center in Florida, at 5:48 p.m. EDT and 7:23 p.m., followed by two at Edwards Air Force Base in California's Mojave Desert, at 8:53 p.m. and 10:28 p.m. All four opportunities come on successive orbits roughly 90 minutes apart.
The astronauts were awakened at 9:30 a.m. EDT by a recording of Aaron Tippin's "Big Boy Toys" radioed up for commander Frederick "C.J." Sturckow.
"Good morning, Houston," Sturckow called down. "It's another great day in space and we hope the weather works out and we can get to land the space shuttle Discovery today."
Two attempts to land in Florida on Thursday were waved off due to showers and thunderstorms within 30 nautical miles of the Kennedy Space Center runway. The Spaceflight Meteorology Group at the Johnson Space Center in Houston is predicting more of the same, if not worse, today with scattered clouds at 3,000 and 8,000 feet, a broken deck at 25,000 feet, winds from 130 degrees gusting to 12 knots and thunderstorms within the no-rain zone.
The forecast for the first opportunity at Edwards calls for ideal conditions with scattered clouds at 10,000 feet, a broken deck at 25,000 feet and winds out 210 degrees with gusts to 12 knots. The wind changes to 240 degrees with gusts to 18 knots for the second opportunity, but that is still within limits.
If those forecasts hold up, entry Flight Director Richard Jones may wave off the first Florida opportunity early, set up for the second and if that doesn't work out, divert the crew to Edwards.
Discovery has enough on-board supplies to remain in orbit through Sunday, but NASA does not schedule landings on the final day in case of a technical problem or bad weather. In this case, Saturday is the last available day for a planned landing and Jones initially said he would keep the crew up as long as there was a reasonable chance to get Discovery back to Florida.
But given the current forecast, with more bad weather expected near the Kennedy Space Center on Saturday, Jones is expected to bring Discovery down today, at Kennedy or Edwards.
Here are detailed timelines for all four landing opportunities (in EDT):
EDT...........EVENT Rev. 217 Deorbit to KSC Deorbit burn: 04:41:37 PM Change in velocity: 187 mph Burn duration: 02:42 Crossrange: 581 sm Range to KSC from EI: 5,048 sm Turn: 230-degree left Runway: 15 Landing: 05:48:57 PM EOM miles flown: 5.7 million12:41 PM......Begin deorbit timeline 12:56 PM......Radiator stow 01:06 PM......Mission specialists seat installation 01:12 PM......Computers set for deorbit prep 01:16 PM......Hydraulic system configuration 01:41 PM......Flash evaporator checkout 01:47 PM......Final payload deactivation 02:01 PM......Payload bay doors closed 02:11 PM......Mission control 'go' for OPS-3 02:21 PM......OPS-3 transition 02:46 PM......Entry switchlist verification 02:56 PM......Deorbit PAD update 03:01 PM......Crew entry review 03:16 PM......CDR/PLT don entry suits 03:33 PM......IMU alignment 03:41 PM......CDR/PLT strap in; MS suit don 03:58 PM......Shuttle steering check 04:01 PM......Hydraulic system prestart 04:08 PM......Toilet deactivation 04:21 PM......MCC 'go' for deorbit burn 04:27 PM......MS seat ingress 04:36 PM......Single APU start 04:41:37 PM...Deorbit ignition 04:44:19 PM...Deorbit burn complete 05:17:19 PM...Entry interface 05:22:21 PM...1st roll command to left 05:34:48 PM...1st roll left to right 05:35:57 PM...C-band radar acquisition 05:42:34 PM...Velocity less than mach 2.5 05:44:44 PM...Velocity less than mach 1 05:45:37 PM...230-degree left turn to runway 15 05:48:57 PM...Landing Rev. 218 Deorbit to KSC Deorbit burn: 06:17:37 PM Change in velocity: 182 mph Burn duration: 2:38 Crossrange: 399 sm Range to KSC from EI: 5,072 sm Turn: 265-degree left turn Runway: 15 Landing: 07:23:36 PM EOM miles flown: 5.7 million
05:57 PM......MCC 'go' for deorbit burn 06:03 PM......MS seat ingress 06:12 PM......Single APU start 06:17:37 PM...Deorbit ignition 06:20:15 PM...Deorbit burn complete 06:51:55 PM...Entry interface 06:56:54 PM...1st roll command to right 07:08:04 PM...1st right-to-left roll reversal 07:10:36 PM...C-band radar acquisition 07:17:12 PM...Velocity less than mach 2.5 07:19:21 PM...Velocity less than mach 1 07:19:57 PM...265-degree left turn to runway 15 07:23:36 PM...Landing Rev. 219 Deorbit to EDW Deorbit burn: 07:47:37 PM Change in velocity: 182 mph Burn Duration: 2:38 Crossrange: 429 sm Range to EDW from EI: 5,061 sm Turn: 207-degree left turn Runway: EDW 22 Landing: 08:53:34 PM EOM miles flown: 5.8 million
07:27 PM......MCC 'go' for deorbit burn 07:33 PM......MS seat ingress 07:42 PM......Single APU start 07:47:37 PM...Deorbit ignition 07:50:15 PM...Deorbit burn complete 08:22:03 PM...Entry interface 08:27:03 PM...1st roll command to left 08:38:09 PM...1st left-to-right roll reversal 08:40:34 PM...C-band radar acquisition 08:47:18 PM...Velocity less than mach 2.5 08:49:30 PM...Velocity less than mach 1 08:50:25 PM...207 degree left turn to runway 15 08:53:34 PM...Landing Rev. 220 Deorbit to EDW Deorbit burn: 09:23:37 PM Change in velocity: 183 mph Burn Duration: 2:39 Crossrange: 452 sm Range to EDW from EI: 5,038 sm Turn: 185-degree left turn Runway: EDW 22 Landing: 10:28:21 PM EOM miles flown: 5.8 million
09:03 PM......MCC 'go' for deorbit burn 09:09 PM......MS seat ingress 09:18 PM......Single APU start 09:23:37 PM...Deorbit ignition 09:26:16 PM...Deorbit burn complete 09:56:56 PM...Entry interface 10:01:53 PM...1st roll command to right 10:12:59 PM...1st right-to-left roll reversal 10:15:21 PM...C-band radar acquisition 10:22:07 PM...Velocity less than mach 2.5 10:24:19 PM...Velocity less than mach 1 10:25:24 PM...185-degree left turn to runway 22 10:28:21 PM...Landing
7:35 PM, 9/10/09: Shuttle re-entry delayed 24 hours by bad weather (UPDATED at 8 p.m. with updated landing times)
The Discovery astronauts were forced to pass up two landing opportunities Thursday because of dynamic, hard-to-predict weather at the Kennedy Space Center, delaying re-entry until Friday in hopes conditions will improve enough to permit a Florida landing.
Already running one orbit late because of showers and thunderstorms near the shuttle landing strip, commander Frederick Sturckow was told to back out of re-entry preparations for a second and final opportunity at when entry Flight Director Richard Jones could not get comfortable with the forecast.
The decision to wave off was made less than 10 minutes before the planned de-orbit rocket firing at 7:35 p.m.
"We are observed no go and forecast no go," astronaut Eric Boe radioed from mission control. "The showers we were hoping would die out, it just doesn't look like it's coming together for us. There's still some showers in the area."
"OK, Houston, we copy that," Sturckow replied from Discovery. "We know everybody worked it as hard as they could and we'll look forward to trying again tomorrow."
Sturckow, pilot Kevin Ford, flight engineer Jose Hernandez, Patrick Forrester, John "Danny" Olivas, European Space Agency astronaut Christer Fuglesang and returning space station flight engineer Timothy Kopra then began work to reopen Discovery's cargo bay doors, setting up for another 24 hours in space.
NASA did not activate its backup landing site at Edwards Air Force Base, Calif., for Thursday's landing attempt, but Jones may reconsider that strategy based on the forecast for Florida.
Discovery has enough supplies to remain in orbit until Sunday at the latest, but NASA would bring the crew down, on one coast or the other, by Saturday if problems prevent a landing Friday.
The Florida forecast calls for several days of unstable weather and Jones may decide to call up Edwards for a Friday landing, depending on how weather plays out.
Here are all of Discovery's landing opportunities through Saturday at both Kennedy and Edwards (all times in EDT):
. ORBIT......DEORBIT.........LANDING.......SITE 09/11 217........04:45 PM........05:48 PM......Kennedy Space Center 218........06:21 PM........07:23 PM......KSC 219........07:50 PM........08:53 PM......Edwards Air Force Base 220........09:26 PM........10:28 PM......EDW 09/12 233........05:04 PM........06:08 PM......KSC 234........06:41 PM........07:43 PM......KSC 235........08:10 PM........09:13 PM......EDW 236........09:46 PM........10:48 PM......EDW
5:25 PM, 9/10/09: Shuttle re-entry delayed one orbit
The shuttle Discovery's crew was told to delay re-entry by one orbit Thursday because of uncertain weather at the Kennedy Space Center. Commander Frederick Sturckow and his six crewmates have one more Florida landing opportunity today, requiring a de-orbit rocket firing at 7:35 p.m., setting up a landing on runway 16 at 8:40 p.m.
If the weather doesn't improve over the next two hours, entry Flight Director Richard Jones will order a 24-hour delay, setting up another round of landing attempts Friday. In that case, NASA could opt to divert Discovery to a backup landing site at Edwards Air Force Base, Calif., Friday or Saturday at the latest, if the Florida weather doesn't improve.
12:20 PM, 9/10/09: Shuttle crew preps for re-entry and landing; maneuvers to avoid possible close encounter with space debris
Keeping tabs on threatening weather, the Discovery astronauts rigged the shuttle for re-entry and landing today at the Kennedy Space Center to close out a successful space station resupply mission.
Shortly after wakeup, commander Frederick Sturckow and pilot Kevin Ford fired Discovery's twin orbital maneuvering rockets for 14 seconds at 12:02 p.m. EDT, adjusting the shuttle's orbit slightly to prevent a possible close encounter with a piece of space debris.
Radar tracking indicated the unidentified debris, which apparently separated from the shuttle-space station complex during a spacewalk Saturday, would pass uncomfortably close to the shuttle around 5 p.m., roughly an hour before the crew's planned de-orbit rocket firing.
The debris avoidance maneuver went well, and the astronauts pressed ahead with re-entry preparations.
Sturckow, Ford and their crewmates - flight engineer Jose Hernandez, Patrick Forrester, John "Danny" Olivas, European Space Agency astronaut Christer Fuglesang and returning space station flight engineer Timothy Kopra - had two landing opportunities Thursday, the first at 7:05 p.m. and the second at 8:42 p.m.
Forecasters with the Spaceflight Meteorology Group at the Johnson Space Center in Houston predicted a chance of showers and possible thunderstorms within 30 nautical miles of the shuttle runway. If such storms are present, Sturckow and company will hold off one orbit and set their sights on the second landing opportunity.
Discovery has enough supplies to remain in orbit until Sunday at the latest and NASA did not activate its backup landing site at Edwards Air Force Base, Calif., for the crew's initial re-entry tries. If the weather or some other issue blocks a Florida landing Thursday, the astronauts will remain in space and extra day and try again Friday.
12:30 AM, 9/10/09: Astronauts may maneuver Thursday to avoid space debris
Radar tracking indicates an unidentified piece of debris that apparently separated from the shuttle Discovery or the International Space Station during a spacewalk Saturday may make a close approach to the shuttle Thursday afternoon.
Before the astronauts went to bed, flight controllers asked commander Frederick Sturckow to power up an additional flight computer to support a possible debris avoidance maneuver shortly after wakeup at 11 a.m. EDT.
"We just got some breaking news from tracking the object that we think left the stack during EVA 3," Stan Love radioed from Houston shortly after midnight. "We're now showing you may get close to that at about MET (mission elapsed time) 12 days 17 hours (5 p.m.). We're looking at the potential for a two OMS (rocket firing), roughly 24-foot-per-second orbit adjust burn, to avoid it.
"The burn will be retrograde, so it won't impact propellant use for deorbit. We'd like to plan on that burn and we'll call it off first thing tomorrow if overnight tracking indicates it's not a threat after all."
Another piece of debris was spotted floating away from Discovery Wednesday afternoon during flight control system checkout. Also unidentified, that debris was not thought to represent any kind of threat to the shuttle.
01:15 PM, 9/9/09: Astronauts pack up, test re-entry systems for Thursday landing (UPDATED at 10:30 p.m. with flight director's landing strategy)
With flight controllers keeping tabs on threatening weather, the Discovery astronauts packed up Wednesday and tested the shuttle's re-entry systems in preparation for landing Thursday at the Kennedy Space Center, weather permitting, to close out a successful space station resupply mission.
Commander Frederick Sturckow and his crewmates - pilot Kevin Ford, flight engineer Jose Hernandez, Patrick Forrester, John "Danny" Olivas, European Space Agency astronaut Christer Fuglesang and returning space station flight engineer Timothy Kopra - have two landing opportunities Wednesday, the first at 7:05 p.m. EDT and the second at 8:42 p.m.
There are no technical problems with the shuttle, but forecasters are predicting rain showers and possible thunderstorms in the Kennedy Space Center area that could cause problems Thursday and Friday.
"The weather tomorrow as (on) the following few days at the Kennedy Space Center, is going to be challenging," entry Flight Director Richard Jones said late Wednesday. "Just like any time here in the late summer, when the sun's out and the daytime heating effects are kind of boiling up the atmosphere a bit, we can expect some rain or some thunderstorms within the area. Hopefully, those thunderstorms are going to be staying away, outside of our 30-nautical-mile flight rule circle we have to keep them out of.
"We had a great chance to look at the weather today as it was streaming into the Kennedy Space Center area. And you could kind of see some lines of convergence, streams of thunderstorms as they were coming into the area. But as they were coming in, you could definitely see some areas of dryness, or some clearing. Hopefully, that same condition will be there tomorrow. Now, it's going to be a little bit iffy in terms of whether that dryness will be there or not, but if it is, that could work in our favor."
The forecast for NASA's backup landing site at Edwards Air Force Base in California's Mojave Desert calls for good conditions for several days in a row.
Discovery has enough supplies to remain in orbit through Sunday at the latest, but NASA managers would bring the ship down Saturday, on one coast or the other, if the weather or technical problems prevent a landing Thursday or Friday. If the Florida weather takes a dramatic turn for the worse, Jones could elect to divert the shuttle to Edwards on Friday. But the going in plan is to shoot for a Florida landing if at all possible.
Earlier Wednesday, Sturckow, Ford and Hernandez tested the shuttle's re-entry systems, firing up one of the ship's three hydraulic power systems, exercising the shuttle's elevons and rudder and test firing the orbiter's primary reaction control system thrusters.
During the flight control system checkout, Fuglesang reported spotting a small piece of debris floating away from the shuttle.
"During the FCS checkout, during the first portion of that when we're running the auxiliary power unit and we do some secondary actuator checks that really shake the vehicle up, we did lose a piece of debris, the crew did capture that in some still shots," Jones said. "We weren't able to come to a definitive conclusion as to what that object was. But we definitively came to the conclusion that it is not a piece of the thermal protection system."
NASA's Mission Management Team, meanwhile, formally cleared Discovery's heat shield for re-entry after a final inspection of the ship's nose cap and wing leading edge panels.
Here are all the landing opportunities available to Discovery's crew Thursday, Friday and Saturday (in EDT):
. ORBIT......DEORBIT........LANDING.......SITE 09/10 202........05:59 PM.......07:05 PM......Kennedy Space Center 203........07:36 PM.......08:42 PM......KSC 09/11 217........04:51 PM........05:54 PM......KSC 218........06:26 PM........07:29 PM......KSC 219........07:56 PM........08:59 PM......Edwards Air Force Base 220........09:32 PM........10:34 PM......EDW 09/12 233........05:15 PM........06:17 PM......KSC 234........06:45 PM........07:48 PM......EDW ...........06:51 PM........07:53 PM......KSC 235........08:20 PM........09:23 PM......EDW 236........09:57 PM........10:59 PM......EDW
The astronauts are scheduled to begin their day at 10:59 a.m. Thursday. Deorbit preparations for the first of the crew's two landing opportunities will begin around 2 p.m. Here are detailed timelines for both opportunities (in EDT):
EDT...........EVENT Rev. 202 deorbit to KSC 01:59 PM......Begin deorbit timeline 02:14 PM......Radiator stow 02:24 PM......Mission specialists seat installation 02:30 PM......Computers set for deorbit prep 02:34 PM......Hydraulic system configuration 02:59 PM......Flash evaporator cooling system checkout 03:05 PM......Final payload deactivation 03:19 PM......Payload bay doors closed 03:29 PM......Mission control 'go' for OPS-3 software load 03:39 PM......OPS-3 entry software loaded 04:04 PM......Entry switch list verification 04:14 PM......Deorbit maneuver update 04:19 PM......Crew entry review 04:34 PM......Commander/pilot don entry suits 04:51 PM......IMU alignment 04:59 PM......CDR/PLT strap in; others don suits 05:16 PM......Shuttle steering check 05:19 PM......Hydraulic system prestart 05:26 PM......Toilet deactivation 05:39 PM......Mission control 'go' for deorbit burn 05:45 PM......Astronaut seat ingress 05:54 PM......Single APU start 05:59:07 PM...Deorbit ignition (dT: 2:55; dV: 202 mph) 06:02:02 PM...Deorbit burn complete 06:33:57 PM...Entry interface (range to KSC: 5,071 miles) 06:38:57 PM...1st roll command to right 06:46:01 PM...1st roll to left 06:52:00 PM...C-band radar acquisition 06:59:14 PM...Velocity less than mach 2.5 07:01:24 PM...Velocity less than mach 1 07:02:09 PM...215-degree left turn to runway 15 07:05:40 PM...Landing Rev. 203 Deorbit to KSC 07:16 PM......MCC 'go' for deorbit burn 07:22 PM......MS seat ingress 07:31 PM......Single APU start 07:36:37 PM...Deorbit ignition 07:39:31 PM...Deorbit burn complete 08:10:03 PM...Entry interface 08:15:00 PM...1st roll command to right 08:31:58 PM...1st right-to-left roll reversal 08:35:44 PM...Velocity less than mach 2.5 08:37:49 PM...Velocity less than mach 1 08:38:00 PM...259-degree left turn to runway 15 08:42:13 PM...Landing
Jones said the weather Thursday likely would be "very challenging."
"I've had a chance to stare at weather, working as a weather flight director and as an ascent and entry flight director on other missions, and the weather's the weather," he said. "You have to kind of watch it and make sure it's behaving in the manner you want it to. And tomorrow ... it's going to look somewhat nasty, it's not going to look 'go' in the early portions of the deorbit prep. We're going to be looking for maybe a trend where it's dissipating as we get closer to the deorbit burn, looking for that area of dryness I was trying to communicate earlier."
3:40 PM, 9/8/09: Shuttle undocks from space station (UPDATING earlier story) (UPDATED at 5:15 p.m. with quotes from commander)
With pilot Kevin Ford at the controls, the shuttle Discovery undocked from the International Space Station today after delivering a fresh crew member and more than 18,500 pounds of needed equipment and supplies.
"Houston and station, from Discovery, physical separation," an astronaut radioed at 3:26 p.m. EDT as powerful springs in the station's docking mechanism gently pushed the shuttle away as the two spacecraft sailed 220 miles above central Asia in orbital darkness.
The space station's docking port recedes from shuttle Discovery.
(Credit: NASA TV)
Kopra was replaced aboard the station by astronaut Nicole Stott, who hitched a ride to the lab complex aboard Discovery. She plans to remain aboard the station until November when another shuttle crew delivers more supplies and equipment.
Ford guided Discovery through a three-quarter-lap fly around, looping up and over the outpost for photo-documentation survey of the outpost before departing the area around 5:10 p.m.
The view of the space station from the shuttle's docking system
camera. (Credit: NASA TV)
"We'd like to extend our thanks to the Expedition 20 crew for all their great support and assistance during the docked mission," Sturckow radioed the station crew. "Thanks especially to Gennady (Padalka, the commander) ... for your great work."
"C.J., thanks so much to you and the whole STS-128 crew and thanks to (lead Flight Director) Heather Rarick and all the ground teams that brought the good ship Discovery to us," flight engineer Michael Barratt replied from the station. "We're pretty fat with supplies now thanks to you, and we're in better shape to carry on the work that we're here to do. You guys have a safe trip home, Discovery, it was great hosting you."
Padalka chimed in, adding "Thank you very much, commander. Have a safe landing."
Shuttle pilots normally use smaller vernier jets, two in the nose and four in the tail, when maneuvering near the station. But one of Discovery's forward verniers suffered a leak shortly after launch, prompting flight controllers to close a shared propellant manifold that took out both forward jets. That action disabled the vernier system for the duration of the fight.
NASA engineers approved an alternate digital autopilot, or ALT-DAP, technique for using the the shuttle's more powerful primary reaction control system jets to reorient the shuttle-station complex for undocking, and for carrying out the planned fly around. Procedures were put in place to make sure no thruster plumes hit the station's delicate solar arrays.
The shuttle Discovery as seen from the station. (Photo: NASA TV)
Sturckow successfully used the big jets for docking and flight controllers did not anticipate any problems for today's fly around.
"It should be a real thrill," Ford told CBS News before launch. "It's the reverse of the docking process. Some hooks will open and some springs will give us a little push off. And then my job is to make sure we stay pretty tight on the tolerances as we back away.
"The exciting part starts when we get to a certain range, maybe about 400 feet, I'll do some ups and we'll start a maneuver that takes the orbiter up and over the top of the space station and we'll do this full 360-degree fly around at about 650 feet.
"It's a great range, it's far enough away that the jets don't really impinge on station and it's also a good range for photography and a chance for us to take a lot of photos of the exterior of the station for documentation. And of course, sometimes the station gets some pictures of the orbiter flying around it. It'll be really spectacular."
Following the fly around, the shuttle crew planned to turn its attention to a final heat shield inspection, using a laser scanner on the end of a 50-foot-long boom to look for any signs of damage to the shuttle's reinforced carbon carbon nose cap and wing leading edge panels.
The so-called "late inspection" is identical to a procedure carried out the day after launch to look for signs of ascent impact damage. This time around, engineers will be looking for any signs of damage from orbital debris or micrometeoroid impacts that might have occurred since the initial inspection.
The late inspection should be complete by around 11 p.m. The astronauts plan to spend the day Wednesday packing up and testing the shuttle's re-entry systems. Landing is targeted for 7:05 p.m. Thursday, weather permitting.
Here is an updated timeline of today's activity (in EDT and mission elapsed time; includes revision N of the NASA television schedule):
EDT........DD...HH...MM...SS...EVENT 09/08 10:59 AM...10...11...00...00...STS/ISS crew wakeup 12:19 PM...10...12...20...00...ISS daily planning conference 01:04 PM...10...13...05...00...Group B computer powerup 01:29 PM...10...13...30...00...Maneuver to undocking attitude 02:44 PM...10...14...45...00...Undocking timeline begins 03:13 PM...10...15...14...12...Sunset 03:26 PM...10...15...27...00...UNDOCKING 03:27 PM...10...15...28...00...Initial separation 03:28 PM...10...15...28...40...ISS holds attitude 03:31 PM...10...15...32...00...Range: 50 feet; reselect -X jets 03:33 PM...10...15...34...00...Range 75 feet; low Z 03:34 PM...10...15...35...00...ISS: Undocking video 03:43 PM...10...15...43...47...Sunrise 03:55 PM...10...15...56...00...Range: 400 feet; start fly around 04:05 PM...10...16...05...30...Range: 600 feet 04:07 PM...10...16...07...30...Shuttle directly above ISS 04:14 PM...10...16...14...46...Noon 04:18 PM...10...16...19...00...Shuttle directly behind ISS 04:30 PM...10...16...30...30...Shuttle directly below ISS 04:41 PM...10...16...42...00...Separation burn No. 1 04:45 PM...10...16...45...44...Sunset 05:09 PM...10...17...10...06...Separation burn No. 2 05:14 PM...10...17...15...00...Post-undocking PGSC reconfig 05:14 PM...10...17...15...00...Group B computer powerdown 05:15 PM...10...17...15...26...Sunrise 05:29 PM...10...17...30...00...Crew meals begin 05:30 PM...10...17...31...00...Post-MMT briefing 05:59 PM...10...18...00...00...OBSS starboard wing survey 07:39 PM...10...19...40...00...Nose cap survey 07:49 PM...10...19...50...00...EVA unpack and stow 08:19 PM...10...20...20...00...PST ISS EVA entry preps 08:29 PM...10...20...30...00...Port wing survey 09:00 PM...10...21...01...00...Mission status briefing 11:14 PM...10...23...15...00...OBSS berthing 09/09 12:14 AM...11...00...15...00...SRMS powerdown 01:09 AM...11...01...10...00...Undocking video playback 02:59 AM...11...03...00...00...STS crew sleep begins 03:00 AM...11...03...01...00...Daily highlights 10:59 AM...11...11...00...00...Crew wakeup
11:20 PM, 9/7/09: Leonardo cargo module moved from space station to shuttle Discovery's cargo bay; farewell ceremony (UPDATED at 1 a.m.; debris avoidance maneuver not needed)
Closing out a successful resupply mission, two Discovery astronauts, operating the International Space Station's robot arm, detached a cargo module from the lab complex late Monday and returned it to the shuttle's cargo bay for the trip back to Earth Thursday.
One orbit later, the seven shuttle fliers bid farewell to the station's six-person crew and floated back into Discovery for the last time, setting the stage for undocking Tuesday afternoon.
Shuttle skipper Frederick Sturckow, left, shakes hands with station
commander Gennady Padalka during a brief farewell ceremony.
(Credit: NASA TV)
"Well Gennady, all good things come to an end," shuttle commander Frederick Sturckow told station skipper Gennady Padalka. "There were many challenges on this mission and they were surmounted through the great efforts of the combined crews working together with our mission control centers in Houston and Moscow. Thank you very much to you and your crew for your wonderful support during the 17A docked mission.
"Thank you very much for these warm words," Padalka replied. "The ISS crew was very happy to help you, we tried to do our best. You did a great job associated with space station building, supplies and maintenance."
A few minutes later, after a final round of hugs and handshakes, the shuttle astronauts floated back into Discovery's cabin. Shortly after that, at 11:11 p.m. EDT, hatches between the two spacecraft were closed.
Sturckow waves farewell, the last shuttle crew member to
depart the station. (Credit: NASA TV)
The farewell ceremony followed the routine-but-intricate transfer of the Leonardo module from the station's Harmony cabin to the shuttle's cargo bay, the final chapter in a busy mission to deliver some nine tons of equipment and supplies to the space station.
Loaded with 2,412 pounds of no-longer-needed hardware and trash, the Leonardo multi-purpose logistics module was disconnected from the station's forward Harmony module around 8 p.m. Shuttle pilot Kevin Ford and Jose Hernandez, operating the space station's robot arm, carefully moved the module to Discovery's payload bay where it was locked down shortly after 9 p.m.
Along with 1,950 pounds of hardware returning on a pallet directly behind Leonardo, and another 861 pounds of gear stowed in the shuttle's crew cabin, Discovery will be bringing home 5,223 pounds of no-longer-needed equipment, parts and trash. In contrast, the shuttle crew delivered 18,548 pounds of equipment and supplies, most of it inside the Leonardo module.
The Leonardo cargo module, being moved from the space station
to the shuttle Discovery's cargo bay for return to Earth.
(Credit: NASA TV)
The MPLM locked in Discovery's cargo bay.
(Credit: NASA TV)
With the cargo module safely stowed, Discovery's space station resupply mission was over. The combined 13-member shuttle-station crew held a brief farewell ceremony around 10:30 p.m. before closing hatches between the two spacecraft in preparation for undocking Tuesday afternoon.
Outgoing flight engineer Timothy Kopra, whose stay in space was shortened because of a month-long launch delay, will join Sturckow, Ford, Hernandez, John "Danny" Olivas, Patrick Forrester and European Space Agency astronaut Christer Fuglesang for the trip back to Earth.
His replacement, Nicole Stott, will remain behind aboard the station with Expedition 20 commander Padalka, Michael Barratt, cosmonaut Roman Romanenko, European Space Agency astronaut Frank De Winne and Canadian astronaut Robert Thirsk.
Undocking is targeted for 3:26 p.m. Tuesday.
"Special thanks to crewmate Tim Kopra," Padalka said Monday evening. "Thank you for working with us. Unfortunately, your flight wasn't so long as you wanted, but that's life. Nevertheless, we would like to be sure that you'll be assigned as soon as possible, for the next flight! OK guys. Have a safe trip and have a safe landing."
"Thank you very much," Sturckow replied.
Hugs and handshakes before the shuttle crew's departure.
(Credit: NASA TV)
Barratt then rang the ship's bell in the Harmony module, following naval tradition by formally announcing "U.S. space shuttle Discovery, departing. ISS flight engineer Col. Timothy Kopra, departing."
Earlier Monday, flight controllers assessed a possible close encounter between the space station and debris from a Chinese satellite early Wednesday on two successive orbits.
Shuttle Flight Director Tony Ceccacci said a preliminary assessment showed the debris from a Chinese weather satellite that was deliberately destroyed in a test of anti-satellite technology, would pass within about 31 miles of the station around 3:30 a.m. Wednesday and within about 16 miles one orbit later.
Additional tracking late Monday showed the debris posed no threat to the shuttle or the station and planning for a possible debris avoidance maneuver was called off.
11:35 AM, 9/7/09: Leonardo berthing on tap; farewell ceremony and hatch closure late today
The Discovery astronauts plan to detach the Leonardo cargo module from the International Space Station today and berth it in the shuttle's cargo bay for return to Earth. After a late-night farewell ceremony, hatches between the shuttle and station will be closed, setting the stage for undocking Tuesday.
The astronauts, awakened at 11:30 a.m. EDT, will egress Leonardo around 1:34 p.m., deactivate the module and depressurize the vestibule between Leonardo and the station's Harmony module at 3:44 p.m. With the station's robot arm locked onto a grapple fixture, motor-driven bolts in the common berthing mechanism will be withdrawn and the cargo module will be detached around 7:30 p.m.
If all goes well, the module, loaded with 2,412 pounds of no-longer-needed hardware and trash, will be locked in Discovery's cargo bay by around 9 p.m. The shuttle also is returning 1,950 pounds of hardware on a pallet mounted behind Leonardo and 861 pounds of gear stowed in the ship's crew cabin.
"We're going to do today the opposite of what we did when we put the MPLM (Leonardo multi-purpose logistics module) on the vehicle," said space station Flight Director Royce Renfrew. "When the crew gets after it today, they'll maneuver the arm in (to) grapple the MPLM and then they'll go back and drive the bolts in the CBM (common berthing mechanism) out then the operators will take the MPLM ... and put it back in the payload bay.
"So essentially we're going to do exactly opposite of what we did when we took the MPLM out of the cargo bay and put it on the stack."
After Leonardo has been berthed, the combined 13-member shuttle station crew will gather for a farewell ceremony in the Harmony module at 10:29 p.m. Hatches between the two spacecraft will be closed around 10:44 p.m. to set the stage for undocking Tuesday afternoon.
Nicole Stott, who hitched a ride to the station aboard Discovery, will remain with the Expedition 20 crew when the Discovery astronauts move back aboard the shuttle this evening. Outgoing flight engineer Timothy Kopra, launched to the station in July, will exit with the shuttle crew, taking Stott's place aboard Discovery for the trip home.
"I'm really going to miss this place," Kopra said during an orbital news conference last week. "This experience has completely exceeded anything that I thought it would be like, just the sights, the sounds, the experiences with a great crew and really being part of two shuttle missions. It's been absolutely phenomenal.
"The main thing, obviously, I'm looking forward to is seeing my family again, my wife and two kids. And maybe have a sip of a beer once I get home."
Here is an updated timeline of today's activity (in EDT and mission elapsed time; includes revision K of the NASA television schedule):
EDT........DD...HH...MM...EVENT 09/07 Mon 11:29 AM...09...11...30...STS/ISS crew wakeup Mon 12:59 PM...09...13...00...ISS daily planning conference Mon 01:34 PM...09...13...35...Cargo module (MPLM) egress Mon 01:54 PM...09...13...55...MPLM deactivation Mon 02:09 PM...09...14...10...PAO event Mon 02:14 PM...09...14...15...MPLM vestibule demate Mon 02:24 PM...09...14...25...Post-EVA transfer/reconfig Mon 03:44 PM...09...15...45...MPLM vestibule depressurization Mon 05:14 PM...09...17...15...Crew meals begin Mon 06:14 PM...09...18...15...Station arm (SSRMS) grapples MPLM Mon 06:44 PM...09...18...45...Common berthing mechanism demate Mon 07:29 PM...09...19...30...MPLM uninstall Mon 08:44 PM...09...20...45...MPLM locked in payload bay Mon 08:59 PM...09...21...00...SSRMS ungrapples MPLM Mon 10:29 PM...09...22...30...Farewell ceremony Mon 10:44 PM...09...22...45...Egress and hatch closure Mon 10:49 PM...09...22...50...Rendezvous tools checkout Mon 11:14 PM...09...23...15...Leak checks 09/08 Tue 12:59 AM...10...01...00...ISS evening planning conference Tue 02:29 AM...10...02...30...ISS crew sleep begins Tue 02:59 AM...10...03...00...STS crew sleep begins
01:10 PM, 9/6/09: Astronauts wrap up logistics transfers
Sailing into the home stretch of a busy space station resupply mission, the Discovery astronauts worked Sunday to wrap up equipment and supply transfers before taking a half day off to relax and enjoy the view.
Overnight, engineers successfully tested a new motor-driven bolt in the berthing mechanism holding the shuttle-delivered Leonardo cargo module in place on the Earth-facing port of the lab's Harmony module. The bolt, one of 16 in the complex interface, jammed during earlier tests and flight engineers Timothy Kopra and Robert Thirsk carried out a lengthy replacement procedure Saturday.
"The checkout activity went perfectly fine, the bolt that jammed on us the other day when we tried to drive it out of the interface ... we worked it this evening and it worked just fine," station Flight Director Royce Renfrew said early Sunday.
"The crew was also interested in watching us do this so they stayed up a little bit late past their bedtime and set a camera up for us and then as my operational support officer, the in-flight maintenance guys drove the mechanisms in there we got to see that on live downlink."
The testing confirmed the astronauts will have no trouble detaching the Leonardo module Monday so it can be stowed in the shuttle Discovery's cargo bay for return to Earth. It also cleared the way for the arrival later this month of Japan's new HTV cargo ship, scheduled for launch Sept. 10, the same day Discovery returns to Earth. The HTV cargo craft will be docked at the same port used by Leonardo.
"All in all, what we wound up doing was verifying for the HTV mission that's coming up that that particular bolt's not going to give us any more problems," Renfrew said. "I was really happy we got all that done."
After the bolt was replaced, flight engineers Michael Barratt and Frank De Winne carried out another lengthy procedure to replace a filter in the U.S. oxygen generation system. Based on a performance degradation, engineers suspected the filter was clogged and sure enough, Barratt and De Winne reported it was 70 to 80 percent blocked by debris.
The astronauts were awakened at 11:35 a.m. Sunday to begin their 10th flight day. As of Sunday morning, the crew had completed about 85 percent of the required logistics transfers to and from the station. The astronauts will continue transfers today before taking a half-day off starting at 8:30 p.m.
The Leonardo module was loaded with some 7.5 tons of equipment and supplies, including two science racks, an experiment sample freezer, a crew sleep station, a carbon dioxide removal assembly, a stowage rack, food, clothing and other gear.
During three spacewalks last Tuesday, Thursday and Saturday, John "Danny" Olivas, Christer Fuglesang and Nicole Stott replaced a 1,800-pound ammonia coolant tank, retrieved two space exposure experiments, deployed a cargo mounting mechanism, installed two GPS antennas and replaced a blown circuit breaker and a rate gyro assembly that helps determine the station's orientation in space.
Renfrew said the new equipment had been checked out and was working normally.
"We had planned that we would spend a couple of days calibrating the (rate gyro assembly) before we ever actually integrated them into the system," he said. "But after the EVA, we went ahead and turned them on and started comparing the solutions that our new rate gyro was giving us compared to the solutions our old rate gyro, the one that's still on the vehicle, was giving us. They turned out to be identical. So we're very happy with the rate gyro 2 that we installed. I don't think we're going to have to calibrate it at all."
The only problems of any significance other than the stuck docking system bolt and the clogged filter in the oxygen assembly were two external wiring problems.
During the crew's second spacewalk, Olivas was directed to hook up two power cables to drive heaters in pressurized mating adapter No. 3, a docking port currently mounted on the multi-hatch Unity module's left port. The idea was to open the docking adaptor later to temporarily store supplies.
But Olivas was unable to make the required electrical connections because the cables were not in the correct position. As it turns out, the wiring bundles were attached to PMA-3 assuming the module would be oriented, or "clocked," in a specific way, putting the connectors within reach of their counterparts on the Unity module.
When PMA-3 was docked to Unity's nadir, or Earth-facing port, the cables and connectors were in the expected orientation. But when PMA-3 was recently moved to Unity's left-side port, it was clocked 180 degrees from the orientation the installers of the wiring bundle apparently expected. The module was in the correct orientation, officials said, but the cables ended up 90 degrees away from the corresponding connectors.
"I still don't know why we have a disconnect between what we were expecting to see there and what actually happened," said station Flight Director Heather Rarick. "I do know that HTV was planning for it to be in this orientation, so at least there are no issues with what we need to do ahead of us."
PMA-3 is scheduled to be moved back to Unity's nadir port in December and in the long term, the wiring issue will have no impact. But in the near term, the stubby module will not be used to store supplies because without heaters, condensation control could prove difficult.
"We can certainly live without the PMA-3 heater cables at this point," Rarick said.
The other wiring problem encountered by Discovery's crew occurred during the third spacewalk Saturday. Olivas and Fuglesang routed two 60-foot-long cable bundles to deliver power and data to a new module - node 3, or "Tranquility" - scheduled for launch next year. Seven of eight connectors hooked up properly, but one power cable's connector could not be plugged in. Engineers are looking into possible work arounds.
The astronauts will field questions from reporters in three round-robin interviews starting at 1:54 p.m. A mission status briefing is scheduled for 5 p.m.
Here is an updated timeline of today's activity (in EDT and mission elapsed time; includes revision K of the NASA television schedule):
EDT........DD...HH...MM...EVENT 09/06 11:29 AM...08...11...30...Crew wakeup 12:59 PM...08...13...00...ISS daily planning conference 01:54 PM...08...13...55...PAO event 02:34 PM...08...14...35...Logistics transfers resume 03:39 PM...08...15...40...Node 2 nadir CBM controller install 05:00 PM...08...17...01...Mission status briefing 05:59 PM...08...18...00...SAFER jetpack checkout 06:29 PM...08...18...30...Crew meals begin 08:29 PM...08...20...30...Shuttle crew off duty 09/07 12:24 AM...09...25...00...ISS daily planning conference 12:29 AM...09...30...00...Transfer tagup 01:19 AM...09...01...20...European Space Agency PAO event 02:59 AM...09...03...00...ISS crew sleep begins 03:29 AM...09...03...30...STS crew sleep begins 04:00 AM...09...04...01...Daily highlights reel 08:30 AM...09...08...31...Flight director's update 11:29 AM...09...11...30...Crew wakeup
11:55 PM, 9/5/09: Spacewalk No. 3 ends; astronauts install cables, but run into balky connector, detached helmet cam (UPDATED at x:xx a.m. with post-spacewalk briefing
Astronauts John "Danny" Olivas and Christer Fuglesang snaked 60-foot-long electrical cables along the space station's hull to a port where a new module will be attached next year to complete the final major objective of a mostly trouble-free seven-hour one-minute spacewalk.
But one power cable refused to plug in properly, forcing Fuglesang to wrap it in insulation and leave it for a future assembly crew to deal with. While he was finishing up that task, his helmet camera housing somehow detached from his spacesuit. It was still connected by a power cable, but the astronauts were worried it might come off and float away.
Danny Olivas' helmet cam view of crewmate Christer Fuglesang,
showing his detached helmet camera. (Photo: NASA TV)
Olivas disconnected the cable for his crewmate and removed the helmet camera assembly. Fuglesang, now lacking helmet lights as well, headed back to the airlock before a fast-approaching sunset.
"And Christer, no need to rush, but hurry every chance you get," Patrick Forrester radioed from inside the shuttle Discovery. "Sunset in about six minutes."
Mission control then chimed in, reassuring the astronauts that "Christer can use his helmet light as a flashlight, since it does still function, on his way back."
A few moments later, back at the station's airlock, Fuglesang said, "my guess is, when I was working that connector my helmet bumped into those cables at some point. It must have very unluckily unlocked it."
"Maybe so," Olivas agreed.
The spacewalk ended at 11:40 p.m. when the astronauts began repressurizing the Quest airlock module.
Danny Olivas works near the so-called "rat's nest" of electrical
connectors at the center of the station's solar power truss.
(Photo: NASA TV)
The balky connector and the detached helmet camera were the only hiccups in an otherwise smooth-sailing spacewalk. The astronauts successfully deployed a payload attachment mechanism on the right side of the lab's solar power truss; replaced a circuit breaker and an orientation control sensor; and installed two Global Positioning System satellite antennas.
The spacewalkers then turned their attention to unrolling two spools of electrical cables, using copper wire ties to secure them along a circuitous path running 60 feet from a power panel to the left-side port of the Unity module where a new module - Tranquility - will be attached next year.
"And some good news to share," Robert Hanley radioed from mission control in Houston. "All the ORUs (circuit breaker and rate gyro assembly) that you've installed have been powered up and are operational."
"That's great news, Houston," Forrester replied.
The two GPS anteannas also passed initial tests.
In two earlier spacewalks last Tuesday and Thursday, Olivas, Fuglesang and Nicole Stott replaced a massive ammonia coolant tank and retrieved a pair of experiments for return to Earth. The astronauts also accomplished a handful of get-ahead tasks.
Total EVA time through three spacewalks was 20 hours and 15 minutes. The overall total through 133 spacewalks since station assesmbly began in 1998 is 830 hours and 51 minutes.
Olivas' total through five spacewalks over two mission stands at 34 hours and 28 minutes, moving him up to 25th on the list of most experienced spacewalkers. Fuglesang, who also has five spacewalks in two missions, has logged 31 hours and 54 minutes of EVA time, moviong him up to 29th on the list.
7:45 PM, 9/5/09: Circuit breaker, rate gyro assembly installed
Spacewalkers John "Danny" Olivas and Christer Fuglesang have replaced a remote power control module circuit breaker in the space station's solar power truss, along with a new rate gyro assembly orientation sensor. The astronauts now are working to install two GPS antennas before moving on to their final major task, unreeling and securing two 60-foot-long power and data cables needed for a new module.
Olivas' helmet cam view of a space station GPS antenna.
(Photo: NASA TV)
There have been no problems of any significance and the spacewalkers are running more than a half hour ahead of schedule.
6:25 PM, 9/5/09:Cargo attachment mechanism deployed
Spacewalkers John "Danny" Olivas and Christer Fuglesang successfully deployed a complex payload attachment mechanism on the right side of the space station's solar power truss today to complete the first objective of the excursion.
Olivas and Fuglesang move along the starboard power truss after
deploying the payload attach system mechanism. (Photo: NASA TV)
The mechanism will be used in November to mount an external logistics carrier, or ELC, holding a high pressure gas tank, a spare control moment gyroscope, a cooling system pump module, a robot arm transporter umbilical system and other hardware.
Olivas and Fuglesang now plan to replace an orientation-sensing rate gyro assembly in the station's solar power truss before installing two GPS antennas and a replacement remote power control module circuit breaker.
Olivas and Fuglesang collect tools after deploying the PAS mechanism.
(Photo: NASA TV)
Olivas' helmet cam view of the PAS mechanism. Some assembly required.
(Photo: NASA TV)
Inside the space station, meanwhile, flight engineer Robert Thirsk and Timothy Kopra successfully replaced a jammed bolt in the Harmony module's lower berthing mechanism. Michael Barratt and Frank De Winne now plan to replace a presumably clogged filter in the station's U.S. oxygen generation system.
4:50 PM, 9/5/09: Spacewalk No. 3 begins
Floating in the space station's Quest airlock module, astronauts John "Danny" Olivas and Christer Fuglesang switched their spaceswuits to battery power at 4:39 p.m. EDT to officially kick off a planned six-and-a-half-hour spacewalk.
"You guys have a great EVA," radioed Jose Hernandez after helping the spacewalkers suit up.
"Great job, Jose, we'll see you in a few hours," Olivas replied.
After setting up tools and tethers, the spacewalkers will make their way to the right side of the station's solar power truss to deploy a payload mounting mechanism needed later this year to store spare parts.
Danny Olivas floats out of the Quest airlock. (Photo: NASA TV)
Previous crews ran into problems deploying similar mechanisms on the left side of the power truss. Olivas and Fuglesang are carrying a special tool to help free any linkages that might prove stiff or locked in place.
While the spacewalkers were suiting up, station flight engineer Robert Thirsk and Timothy Kopra started a lengthy repair job to replace one of 16 motor-driven bolts in the berthing mechanism of the Harmony module's Earth-facing port.
Amid spacewalk preparations, astronauts Robert Thirsk and Timothy
Kopra worked to replace one of 16 bolts in the Harmony module's
Earth facing docking mechanism. (Photo: NASA TV)
During attachment of a cargo module carried aloft by Discovery, engineers noticed higher-than-expected motor currents. During a test earlier this week, the bolt in question jammed, prompting a decision to replace the bolt today.
12:30 PM, 9/5/09: Astronauts set for final spacewalk
Astronauts John "Danny" Olivas and Christer Fuglesang are gearing up for a third and final spacewalk today, a planned six-and-a-half-hour excursion to deploy a payload mounting mechanism, replace a circuit breaker and an orientation sensor, install GPS antennas and to lay 60 feet of cable to power a new module.
The spacewalk is scheduled to begin at 4:49 p.m. EDT, although the astronauts could get out early if preparations go smoothly. For identification, Olivas, call sign EV-1, will be wearing a spacesuit with red stripes around the legs. Fuglesang, EV-2, will be wearing an unmarked suit.
This will be the 133rd spacewalk devoted to station assembly and maintenance since construction began in 1998 and the 14th so far this year. Going into today's excursion, station assembly EVA time stood at 823 hours and 50 minutes, including 13 hours and 14 minutes for Discovery's crew.
Today's spacewalk was replanned following an EVA Thursday in which Olivas ran into problems routing a power cable on a docking port where a new module is scheduled to be attached next year. A bundle of four cables was not in the expected position on the port and that task was dropped from the Discovery crew's timeline pending additional analysis. Longer jumper cables likely will be needed to hook up the cables in question.
"On EVA-2, when we got to the get aheads and discovered the cables weren't in exactly the right config we intended them to be in, we called the crew off and thought about it for the rest of the day," said space station Flight Director Royce Renfrew. "We went ahead and pulled that off the EVA-3 timeline and added some other get-ahead tasks. It's actually a fairly full timeline."
The first item on the agenda is to deploy a payload attachment mechanism on the upper right side of the station's solar power truss. The mechanism will be needed in November when the crew of the next shuttle visiting the station delivers two external logistics carriers, or ELCs, carrying critical spare parts and components.
ELC-1, which will be mounted on the left-side port-3 truss segment, will carry a solar array battery charge/discharge unit, a plasma contactor unit, a robot arm latching end effector, a control moment gyroscope, a nitrogen tank assembly, an ammonia tank assembly and a cooling system pump module.
ELC-2, which will be mounted on the starboard-3 truss attach mechanism being deployed today, will carry a high pressure gas tank, another control moment gyroscope, a pump module, a robot arm transporter umbilical system, experiment support equipment and flight attachment mechanisms.
"We're also going to go play with the rate gyro assembly," Renfrew said. "When we go around the Earth, we not only need to know where we are and how fast we're going, but one of the things we need to know to be able to do attitude determination and to essentially point the vehicle in the right direction is know how fast we're actually moving in any axis.
"So if we're pitching or yawing or rolling, if we're changing the attitude of the stack in any of those three (axes), we need to know how fast we're actually changing there. So we have some pretty high-tech equipment on the vehicle, the rate gyro assemblies. One of those has failed. On this EVA we'll go replace that rate gyro. We're also going to replace two GPS antennas, Global Positioning System antennas."
While Olivas replaces the first of two GPS antennas, Fuglesang will remove a failed remote power control module, or RPCM, in the power truss electrical system. The work requires a partial shut down of critical systems, including a stabilizing gyroscope and one of the station's two external cooling loops.
"When we go to change that out, we have to get the safing in place before the EV crew members can safely handle that RPCM," Renfrew said. "In order to get the safing in place, we have to go upstream to a different power module and power it off there. Somewhat similar to if you're in your house and you wanted to go change out a plug in the wall, you'd probably go outside and turn the circuit breaker off to make sure that's not live.ÊSame thing here, only when we go upstream of that RPCM it turns off a lot of equipment on the truss.
"That's pretty complicated and requires a lot of choreography between the EV crew and the ground to make all that work flawlessly."
Finally, Olivas and Fuglesang will work together to run 60-foot-long cables from a distribution box in the solar power truss down to the left side of the Unity connecting module where a new module, known as node 3, or Tranquility, is scheduled for attachment early next year.
"These cables are about an inch and a half of two inches in diameter and they're really stiff," said Zeb Scoville, the lead spacewalk officer for Discovery's mission. "We've coiled up loops of this cable into maybe a diameter of about two feet. With each coil, we've taken one of these copper wire ties ... and we twist each loop with one of these wire ties.
"As they pull off one loop, they can release that one wire tie, pull off maybe just five or so feet, secure that down to structure while they hold onto the rest of it, they can move down the truss structure a little bit, undo one twist tie, get the second loop off and start working on that. As controlled as that may sound, cables have always presented a challenge in the past just because they do have a lot of memory and sort of a mind of their own. We've done our best to try to control that."
While the spacewalk is going on, returning station astronaut Timothy Kopra and station flight engineer Robert Thirsk will spend three hours or so replacing one of 16 motor-driven bolts holding the Leonardo cargo module to the Harmony module's Earth-facing port. Engineers noticed higher-than-normal drive currents in the bolt earlier and during a test this week, it jammed.
"Unfortunately, Murphy's Law holds true because the one bolt that we're after is buried under a bunch of other structure," Renfrew said. "We'll take that out, put it back together. ... It'll be about a three-hour task. That'll all be taken care of before we need to get the MPLM (Leonardo cargo module) off the vehicle."
Finally, station flight engineers Michael Barratt and Frank De Winne will spend their afternoon replacing a presumably clogged filter in the U.S. oxygen generation assembly.
Here is an updated timeline of today's activity (in EDT and mission elapsed time; includes revision I of the NASA television schedule):
EDT........DD...HH...MM...EVENT 09/05 11:59 AM...07...12...00...STS/ISS crew wakeup 12:34 PM...07...12...35...EVA-3: 14.7 psi repress/hygiene break 01:24 PM...07...13...25...EVA-3: Airlock depress to 10.2 psi 01:29 PM...07...13...30...ISS daily planning conference 01:44 PM...07...13...45...ISS: Harmony nadir CBM bolt replacement 01:44 PM...07...13...45...EVA-3: Campout EVA preps 03:14 PM...07...15...15...EVA-3: Spacesuit purge 03:29 PM...07...15...30...EVA-3: Spacesuit prebreathe 04:14 PM...07...16...15...MPLM transfers resume 04:19 PM...07...16...20...EVA-3: Crew lock depressurization 04:49 PM...07...16...50...EVA-3: Spacesuits to battery power 04:54 PM...07...16...55...EVA-3: Airlock egress 05:09 PM...07...17...10...EVA-3: Setup 05:24 PM...07...17...25...EVA-3: S3 upper payload attach deploy 06:54 PM...07...18...55...EVA-3: Rate gyro assembly 2 R&R 07:54 PM...07...19...55...EVA-3/EV-1: GPS-4 antenna install 07:54 PM...07...19...55...EVA-3/EV-2: S0 RPCM R&R 08:39 PM...07...20...40...EVA-3/EV-1: Node 3 cable routing 08:39 PM...07...20...40...EVA-3/EV-2: GPS-2 antenna install 08:59 PM...07...21...00...ISS: OGS filter replacement 08:59 PM...07...21...00...EVA-3/EV-2: Node 3 cable routing 10:24 PM...07...22...25...EVA-3/EV-1: Node 1 slide wire removal 10:44 PM...07...22...45...EVA-3: Cleanup and ingress 10:44 PM...07...22...45...ISS: "Buzz" EVA video 11:19 PM...07...23...20...EVA-3: Airlock repressurization 11:34 PM...07...23...35...Spacesuit servicing 09/06 12:24 AM...08...25...00...Evening planning conference 01:00 AM...08...01...01...Mission status briefing 02:59 AM...08...03...00...ISS crew sleep begins 03:29 AM...08...03...30...STS crew sleep begins 04:00 AM...08...04...01...Daily highlights reel 09:00 AM...08...09...01...Flight director's update 11:29 AM...08...11...30...Crew wakup
7:00 PM, 9/4/09: Engineers study shuttle main engine nozzle leaks; flight director explains debris avoidance guidelines (UPDATED at 11:40 p.m.; correcting odds: 1-in-100,000, not 1-in-10,000; UPDATING at 9:30 a.m. with additional explanation of debris avoidance triggers)
Engineers are looking into what might have caused more than 300 microscopic leaks in the nozzle of a space shuttle main engine used to help launch Endeavour in July. But officials Friday characterized the issue as relatively minor, saying the leaks were well below any threshold that could cause an in-flight problem.
The issue was discovered during post-landing testing Aug. 27 in which helium gas was pumped through the 1,080 coolant tubes that make up the engine nozzle. Hydrogen is routed through the tubes during engine operation to keep the metal from overheating.
Jerry Cook, manager of the main engine project at the Marshall Space Flight Center in Huntsville, Ala., said engineers found some 340 tiny leaks near the top of engine No. 2045's nozzle. Engine No. 2045 was used as Endeavour's center engine, mounted directly under the ship's vertical stabilizer.
.6592"They are microscopic," Cook said in a telephone interview. "As a matter of fact, the total leak rate on the nozzle from all these leaks is so small that it's not even the equivalent of one ruptured tube. They are tiny. The total leak rate in the 340 hot wall leaks that we have is 0.6592 pounds per second. So it's not even equivalent of one tube rupture, nothing you could see in the ascent performance going up hill at all."
Main engine No. 1 being removed from shuttle Endeavour on Aug. 18
at the Kennedy Space Center. (Photo: NASA)
Even so, the sheer number of leaks "is definitely out of the ordinary," he said. "We've got a lot of theories, but honestly, we don't know exactly what caused it. We've got a team down there now doing an investigation."
One possible contributor is corrosion caused by lengthy exposure to the salty environment at the shuttle's sea-side launch pad.
"We're not sure if that's what caused it," Cook said. "We went in and cleaned them off prior to launch, went in and did a leak check, no problems there. So these are small, microscopic holes we see. We've mapped the tubes and we'll see what kind of repair we can do on them."
In the meantime, while the investigation continues, nozzle No. 2031 will be taken out of service. Cook said repairs near the top of the nozzle, near the main engine combustion chamber, can be difficult.
Depending on how the investigation plays out, "we could potentially lose a nozzle from the inventory," Cook said. With just six shuttle flights remaining before the fleet is retired late next year, a lost nozzle could force NASA to shuffle nozzles from engine to engine, but it would "not put us in a situation where we cannot support the manifest."
At the Johnson Space Center in Houston, meanwhile, space station Flight Director Ron Spencer provided a bit more insight into how NASA flight controllers assess the threat posed by orbital debris, and why the International Space Station's orbit was not repositioned even though a large piece of rocket debris passed within eight tenths of a mile earlier Friday.
The debris, from an Ariane 5 rocket launched in 2006, is in a highly elliptical orbit. Radar tracking earlier this week showed it would pass close by the space station around 11:07 a.m. EDT. Flight controllers initially looked into raising the station's orbit but eventually ruled out any such move.
Spencer is the flight director who wrote the rules governing debris avoidance maneuvers, or DAMs.
"The way we do all of this is we get tracking data from Space Command on the objects that are a threat to the space station," he said. "And some of those objects we can track very well, some of them we can't track as well. This one we could track very well, so even though the miss distance was only 1.3 kilometers, we were very confident in our tracking of it so we knew it was going to be a near miss without a threat of collision.
"We actually calculate a probability of collision for all of these items, which factors in the uncertainty we have as to where this object is going to be. Since this object was so well tracked, we calculated a probability of collision of zero. So we knew we were OK."
NASA monitors an imaginary volume around the space station roughly the shape of a pizza box measuring 0.466 miles thick and 15.5 miles square.
"Initially, we have a screening box, which is .75 kilometers radial miss, which would be up or down, by 25 kilometers in cross track, which would be left or right, by 25 kilometers down track, which is either in front or behind us," Spencer said.
"Space Command will alert us of any debris objects out there that are going to get that close to us. Then they increase tasking on those objects to try to get a better solution and decrease the uncertainty. Then we calculate a probability of collision based on the data Space Command gives us."
In a subsequent email exchange, Spencer said NASA has two levels of concern.
"We have two thresholds, yellow and red," he wrote. "The yellow is 1-in-100,000 and the red is 1-in-10,000. We will not take any action if it is below the yellow threshold. If it between the yellow and red, we will only take action if it is easy to do so without impacting the mission. For a red threshold violation we will take action in most cases."
For the debris encountered Friday, no action was required.
12:30 PM, 9/4/09: Astronauts enjoy half day off; crew news conference on tap
The Discovery astronauts and their space station colleagues enjoyed a half-day off Friday, taking a break to relax and enjoy the view from 220 miles up after a grueling week in orbit resupplying the International Space Station.
The astronauts were awakened at 12 p.m. EDT by a recording of Louis Armstrong singing "What a Wonderful World" beamed up from mission control from the family of astronaut John "Danny" Olivas.
An hour before wakeup, around 11:07 a.m., a piece of space debris from an Ariane 5 rocket, traveling several miles per second, passed a scant eight tenths of a mile in front of the space station, as predicted by flight controllers monitoring its path.
Earlier this week, NASA managers considered raising the station's orbit slightly to provide more clearance but ultimately concluded the large, precisely tracked debris posed no threat.
The space station was moving from northwest to southeast over the
Pacific Ocean near the equator Friday when a piece of space debris
streaked safely past. (Photo: MacDoppler Pro)
"The distance was as predicted by the flight controllers here in the space station flight control room," said NASA commentator Nicole Cloutier-Lemasters. "The total miss distance was 1.3 kilometers traveling in front of the space station, traveling from left to right in front of the vehicle, but no concern whatsoever."
The first half of the crew's day will be an off-duty period, followed by a joint meal at 7:29 p.m., a traditional crew portrait at 8:29 p.m. and a news conference at 8:49 p.m.
After that, the astronauts will get back to work, transferring supplies and equipment between the station and the Leonardo cargo module brought up aboard Discovery and preparing tools for a third and final spacewalk Saturday by Olivas and Christer Fuglesang.
Olivas and Fuglesang will spend the night in the station's Quest airlock module at a reduced pressure of 10.2 pounds per square inch to help purge nitrogen from their bloodstreams, part of a protocol designed to prevent the bends after working in NASA's five-psi spacesuits.
Here is an updated timeline of today's activity (in EDT and mission elapsed time; includes revision H of the NASA television schedule):
EDT........DD...HH...MM...EVENT 09/04 11:59 AM...06...12...00...Crew wakeup 01:49 PM...06...13...50...ISS daily planning conference 02:59 PM...06...15...00...Shuttle crew off duty 05:00 PM...06...17...01...Mission status briefing 07:29 PM...06...19...30...Crew meals 08:29 PM...06...20...30...Crew photo 08:49 PM...06...20...50...Crew mews conference 09:34 PM...06...21...35...MPLM transfers resume 09:34 PM...06...21...35...EVA-3: Tools configured 11:14 PM...06...23...15...Equipment lock preps 11:54 PM...06...23...55...EVA-3: Procedures review 09/05 01:14 AM...07...01...15...Evening planning conference 02:24 AM...07...02...25...EVA-3: Mask pre-breathe 03:09 AM...07...03...10...EVA-3: Airlock depress to 10.2 psi 03:29 AM...07...03...30...ISS crew sleep begins 03:59 AM...07...04...00...STS crew sleep begins 04:00 AM...07...04...01...Daily highlights reel 09:30 AM...07...09...31...Flight director's update 11:59 AM...07...12...00...Crew wakeup
1:05 AM, 9/4/09: Spacewalk No. 2 ends (UPDATED at2:45 a.m. with post-EVA briefing)
Astronauts John "Danny" Olivas and Christer Fuglesang began repressurizing the space station's Quest airlock module at 12:51 a.m. EDT Friday to close out a six-hour 39-minute spacewalk. The astronauts successfully installed a 1,700-pound ammonia coolant tank and mounted its depleted predecessor in the shuttle Discovery's cargo bay for return to Earth.
"The new ATA (ammonia tank assembly) has been checked out, it's fully integrated and is doing well," Robert Hanley radioed from mission control after tests confirmed the new tank was properly connected and operating normally.
The space station's robot arm, no longer carrying a depleted
ammonia coolant tank. (Photo: NASA TV)
The spacewalkers completed the tank swap-out ahead of schedule and performed a few "get-ahead" tasks before calling it quits. Fuglesang installed protective covers over cameras on the station's robot arm and a portable foot restraint was positioned on the lab's solar power truss to assist future assembly crews.
Olivas also was asked to plug in a heater cable on a pressurized mating adaptor, but the cable was not where flight controllers expected it to be and he was told to hold off until engineers can assess the situation. If possible, the cable will be plugged in during a third spacewalk Saturday.
This was the 132nd spacewalk devoted to station assembly and maintenance since construction began in 1998, the 13th so far this year and the second of three planned by the shuttle Discovery's crew. The space station EVA total now stands at 823 hours and 50 minutes.
"This was in my mind an extremely successful EVA," said lead spacewalk officer Zeb Scoville. "It was just an amazing sight to watch the crew work so well together, the pace throughout was calm yet efficient and they were able to just bang through these tasks and get them done ahead of schedule all the way through the EVA."
Olivas and Fuglesang plan a third and final spacewalk Saturday evening to deploy an external equipment mountping mechanism, to replace an orientation control device and to run cables needed for a new module scheduled for launch next year.
10:15 PM, 9/3/09: Depleted ammonia tank moved to shuttle payload bay
Astronauts John "Danny" Olivas and Christer Fuglesang are in the process of moving a depleted ammonia coolant tank to the shuttle Discovery's cargo bay. As of 10:15 p.m. EDT, the astronauts were running about 50 minutes ahead of their timeline and may have time to complete a few get-ahead tasks before returning to the Quest airlock.
Astronauts Christer Fuglesang and Danny Olivas work on the space
station's P1 truss, visible above and to the left of the Leonardo cargo,
module in the foreground. (Photo: NASA TV)
Fuglesang, holding a depleted 1,300-pound ammonia tank, 220 miles
above the Pacific Ocean. (Photo: NASA TV)
Fuglesang, anchored to the end of the space station's robot arm,
moves the old ammonia tank to the shuttle Discovery's cargo bay.
(Photo: NASA TV)
Fuglesang (top) holds the depleted ammonia tank while Olivas (below)
assists. (Photo: NASA TV)
8:50 PM, 9/3/09: New ammonia tank installed
Spacewalkers John "Danny" Olivas and Christer Fuglesang successfully muscled a 1,700-pound ammonia coolant tank into place in the International Space Station's solar power truss Thursday to accomplish one of the primary objectives of the Discovery crew's mission.
With Fuglesang on the end of the space station's robot arm and Olivas anchored to a foot restraint on the truss, the astronauts carefully guided big tank into position and began bolting it down shortly after 8 p.m. EDT, about two hours after the spacewalk began.
Astronauts Christer Fuglesang and Danny Olivas work at the back
of the shuttle Discovery's cargo bay to release an ammonia coolant tank.
(Photo: NASA TV)
The astronauts had no problems handling the massive tank, the largest component ever manually moved about by space station assembly crews, and after four bolts were driven home to lock it in place, the spacewalkers began connecting ammonia lines, nitrogen pressurization lines and electrical umbilicals to complete the installation.
Fuglesang, holding the 1,700-pound ammonia tank, is moved to the P1
truss. A depleted ammonia tank is attached to the station's robot arm
as well. (Photo: NASA TV)
The new tank was carried into orbit on a platform at the rear of the shuttle Discovery's cargo bay. Fuglesang and Olivas began the spacewalk by unbolting the ammonia tank assembly, or ATA, at 7:06 p.m., just under an hour into the excursion.
A few minutes later, after Fuglesang took a moment to get a feel for handling the massive tank, arm operator Kevin Ford began slowly moving him from the cargo bay up to the P1 truss, a trip that took about a half hour to complete.
"So far, it's behaving very nicely," Fuglesang commented as the station arm began moving.
"That's good news," Ford replied.
After completing the fluid and electrical line connections, the astronauts will focus on transferring a depleted ammonia tank, removed during a spacewalk Tuesday and temporarily mounted on the station's robot arm, back down to the shuttle Discovery's cargo bay. It will be mounted on the cargo carrier for return to Earth.
6:20 PM, 9/3/09: Spacewalk No. 2 begins
Astronauts John "Danny" Olivas and Christer Fuglesang switched their spacesuits to battery power at 6:12 p.m. EDT to officially kick off a planned six-and-a-half-hour spacewalk to finish up the replacement of an ammonia coolant tank on the International Space Station.
The spacewalk began nearly an hour behind schedule because of time lost opening Olivas' helmet to re-snap a chin strap on his communications cap.
Christer Fuglesang's helmet cam view of the space station.
(Photo: NASA TV)
A depleted ammonia tank was removed from the station's port-one truss segment during a spacewalk Tuesday by Olivas and Nicole Stott and temporarily mounted on the station's robot arm. In today's excursion, Olivas and Fuglesang will remove a new tank from the shuttle Discovery's cargo bay, install it in the P1 truss segment and then stow the depleted tank in the orbiter's payload bay for return to Earth.
1:40 PM, 9/3/09: Astronauts prepare for spacewalk, ammonia tank installation
Astronauts John "Danny" Olivas and Christer Fuglesang are preparing for a six-and-a-half-hour spacewalk to install a new 1,700-pound ammonia coolant tank in the International Space Station's solar power truss. A depleted tank, removed during a spacewalk Tuesday, will be mounted in the shuttle Discovery's cargo bay for return to Earth.
The spacewalk is scheduled to begin around 5:19 p.m. EDT. This will be the 132nd spacewalk devoted to station assembly and maintenance since construction began in 1998, the 13th so far this year and the second of three planned by the shuttle Discovery's crew. Olivas will be making his fourth spacewalk while Fuglesang, a Swedish astronaut representing the European Space Agency, will be making his third.
Olivas and Fuglesang spent the night in the station's Quest airlock at a reduced pressure to help purge nitrogen from their bloodstreams. The astronauts were awakened at 12:30 p.m. by a recording of "There is a God" beamed up from mission control from astronaut Patrick Forrester's family.
During a spacewalk Tuesday, Olivas and space station flight engineer Nicole Stott removed a depleted ammonia tank from the left side of the station's power truss and temporarily mounted it on the lab's robot arm. During today's excursion, Olivas and Fuglesang will remove a fresh tank, loaded with 600 pounds of ammonia coolant, from a carrier in Discovery's cargo bay.
Anchored to the end of the station's arm, operated by astronaut Kevin Ford inside the Destiny lab module, Fuglesang will manually hold the 1,700-pound tank during the trip up to the port-one truss segment where he and Olivas will guide it into place, securing it with bolts at top and bottom.
In graphic at left, Christer Fuglesang, anchored to the space station's robot arm, removes a new ammonia tank from a carrier at the rear of shuttle Discovery's cargo bay. At right, the new tank is installed in the port one truss of the International Space Station. A depleted ammonia tank removed during a spacewalk Tuesday is attached to the robot arm. (Photo: NASA TV)
"EVA 2 is completely dedicated to the ammonia tank assembly replacement," Fuglesang said in a NASA interview. "So after the first EVA, the old tank has been put on the station arm. That's kind of where we (are) starting out now. So EVA 2, we both go down to the payload bay. I will jump into the foot restraint in the arm and then get ready to grab this new tank with my arms and Danny will undo the last bolt. And then, while I'm holding this tank, some seventeen hundred pounds, Kevin Ford will fly me with the arm up to the P1 where the old tank was and then I will install the new tank there."
After making electrical connections and hooking up ammonia coolant lines, Olivas will hold onto the depleted tank and the station arm will release it. Ford then will reposition Fuglesang and Olivas will hand him the old tank.
"We put the new tank in place and then we do a little dancing up there such that the old tank, which was held by the arm, it will be now given to Danny in another foot restraint on the truss. He grabs it and then Kevin swings around the arm again such that I can grab the ATA with my arms, the old one now, and Danny lets go. And then we fly back to the payload bay again."
Once back in the cargo bay, Fuglesang and Olivas will lock the old tank in place on the same carrier that held the new tank for launch and attach insulation blankets. Finally, the grapple fixture used to temporarily stow the tank on the station's robot arm will be removed and attached to an ammonia tank on the right side of the power truss that will be replaced next year.
There is a bit of confusion about what the new tank actually weighs. NASA documents show the tank weighs 1,702 pounds but Olivas, in a NASA interview, said he was present when the tank was weighed at the Kennedy Space Center before launch and "it was eighteen hundred and thirty-six pounds."
Regardless of the actual weight, the ammonia tank assembly is the most massive component ever manually handled by space station astronauts.
"That's a lot of mass," Olivas said before launch. "We'll have one attached to the robotic arm but then we're also going to put an EVA crew member on that same robotic arm holding the new Ammonia Tank Assembly. So it's going to be a handful, not only for the robotic arm. Christer Fuglesang is going to be doing a lot of working out in the gym to be able to wrestle with that eighteen hundred pound mass and he'll be the one who's responsible for making sure that that thing stays where it's supposed to go and that it's well behaved."
Here is an updated timeline of today's activity (in EDT and mission elapsed time; includes revision H of the NASA television schedule):
EDT........DD...HH...MM...EVENT 09/03 12:29 PM...05...12...30...Crew wakeup 01:04 PM...05...13...05...EVA-2: 14.7 psi repress/hygiene break 01:54 PM...05...13...55...EVA-2: Airlock depress to 10.2 psi 02:14 PM...05...14...15...EVA-2: Campout EVA preps 02:29 PM...05...14...30...ISS daily planning conference 03:29 PM...05...15...30...MPLM transfers resume 03:44 PM...05...15...45...EVA-2: Spacesuit purge 03:59 PM...05...16...00...EVA-2: Spacesuit prebreathe 04:49 PM...05...16...50...EVA-2: Crew lock depressurization 05:19 PM...05...17...20...EVA-2: Spacesuits to battery power 05:24 PM...05...17...25...EVA-2: Airlock egress 05:39 PM...05...17...40...EVA-2/EV-1: ATA worksite setup 05:39 PM...05...17...40...EVA-2/EV-2: SSRMS setup 06:14 PM...05...18...15...EVA-2: ATA removal from LMC 07:04 PM...05...19...05...EVA-2/EV-1: Prep for ATA install 07:04 PM...05...19...05...EVA-2/EV-2: Maneuver to ATA install 07:34 PM...05...19...35...EVA-2/EV-1: ATA zenith bolts 07:34 PM...05...19...35...EVA-2/EV-2: ATA nadir bolts 07:59 PM...05...20...00...EVA-2/EV-1: NH3/N2 electrical connects 07:59 PM...05...20...00...EVA-2/EV-2: Prep for ATA handoff 08:24 PM...05...20...25...EVA-2/EV-2: ATA handoff, move to LMC 08:44 PM...05...20...45...EVA-2/EV-1: P1 cleanup; ATA handoff 09:54 PM...05...21...55...EVA-2: ATA intall on LMC 11:14 PM...05...23...15...EVA-2: Cleanup and airlock ingress 11:49 PM...05...23...50...EVA-2: Airlock repressurization 09/04 12:04 AM...06...00...05...Spacesuit servicing 01:14 AM...06...01...15...Evening planning conference 01:30 AM...06...01...31...Mission status briefing on NTV 03:29 AM...06...03...30...0ISS crew sleep begins 03:59 AM...06...04...00...STS crew sleep begins 04:00 AM...06...04...01...Daily highlights reel 09:30 AM...06...09...31...Flight director's update 11:59 AM...06...12...00...Crew wakeup
11:10 AM, 9/3/09: Collision avoidance maneuver not required
Additional radar tracking of debris from an Ariane 5 rocket launched in 2006 shows it will not come close enough to the International Space Station to require an avoidance maneuver, NASA officials said Thursday.
The debris is expected to pass within a few miles of the space station Friday around 11:05 a.m. EDT. Flight controllers had been protectively planning a maneuver to raise the station's orbit slightly if tracking showed the odds of a collision were worse than 1-in-10,000.
"As we got closer and closer to the time of closest approach, the orbits started diverging enough that we got outside of our flight rule limits and this (morning) declared the probability of the two objects coming together in space were zero," said space station Flight Director Royce Renfrew. "So we stood down on any further actions."
9:30 PM, 9/2/09: Space station collision avoidance decision Thursday; engineers optimistic no move needed
Engineers will make a decision late Thursday on whether to raise the International Space Station's orbit slightly to avoid a piece of debris from a European rocket, NASA managers said Wednesday.
The debris, catalog number 29274, apparently is part of the dual-payload "SYLDA" adaptor used by an Ariane 5 rocket that launched Japanese and French communications satellites Sept. 11, 2006. Such adaptors typically weigh around 1,000 pounds, but it's not known if the debris in question is intact. It is in a highly elliptical orbit, with a high point of about 20,000 miles and a low point of around 200 miles.
A projection showing the space station and a derelict rocket body
passing within a few miles of each other Friday morning. The
station's path, moving from northwest to southeast, is shown in blue.
The debris is approaching from the left. (Photo: MacDoppler Pro)
Tracking data indicates the debris will pass within about two miles of the space station at 11:06 a.m. EDT Friday. NASA managers are developing plans to change the station's orbit slightly to widen the miss distance if continued tracking shows more than a 1-in-10,000 chance of a collision.
John McCullough, chief of the flight directors office at the Johnson Space Center in Houston, said a preliminary analysis indicates no such maneuver will be needed. But he cautioned that more accurate tracking data will be available Thursday and that a final decision will be made Thursday evening.
"Right now, it's looking very positive, it's looking like we probably won't have to do that," he said. "But we are building a plan to allow us to make that decision as late as possible."
If a reboost maneuver is required, the shuttle Discovery's primary maneuvering thrusters would be used to impart a 1.1 mph change in velocity over a two-hour period.
"It's called a config-1 reboost," McCullough said. "It's a tail and forward alternating firing of the primary jets. It's about a two-hour maneuver to get a half meter per second, so it's not exactly efficient, but it's a predefined (procedure)."
The station's Russian thrusters can be used for orbit adjustments, but mission managers want to conserve the lab's on-board fuel if possible. McCullough said using the shuttle to do a reboost would have no impact on Discovery's mission.
7:40 PM, 9/2/09: Shuttle heat shield cleared for entry
The shuttle Discovery's heat shield was cleared for re-entry "as is" Wednesday based on a detailed analysis of launch imagery, laser scans conducted by the astronauts the day after launch and a close-up inspection of the shuttle's belly during final approach to the space station.
"The Damage Assessment Team provided their final summary to the team and declared that the TPS (thermal protection system) is acceptable for entry," the MMT said in a summary of Wednesday's meeting.
Minor damage was noted near a so-called "protuberance tile" used to trigger turbulent flow during re-entry as part of a test to collect data on a phenomenon known as the boundary layer transition. But the MMT concluded "there will not be any adverse interaction between the damaged tile and the DTO (developmental test objective)."
Likewise, a protruding plug in an insulation blanket on one of Discovery's aft rocket pods is not considered any sort of threat.
A final inspection of the shuttle's reinforced carbon carbon nose cap and wing leading edge panels will be carried out after undocking from the space station to look for any signs of micrometeoroid impact damage that might have occurred since an idential inspection the day after launch.
3:30 PM, 9/2/09: Astronauts focus on equipment transfers; prepare for Thursday spacewalk; NASA considers possible maneuver to avoid space debris (UPDATED at 4:45 p.m.; debris avoidance maneuver unlikely)
The Discovery astronauts focused on equipment transfers Wednesday, moving science racks and other gear into the International Space Station from a cargo module delivered by the shuttle. Flight controllers, meanwhile, studied the track of a derelict European rocket body to determine if an avoidance maneuver might be necessary.
The debris, believed to be from an Ariane 5 rocket, is in an orbit with a high point of nearly 20,000 miles and a low point of just under 200 miles. It is the low point of the ellipse that concerns flight planners, with tracking data suggesting a flyby Friday at 11:05 a.m. EDT just seven miles from the station.
Space station and shuttle flight controllers "have been keeping an eye on this object, which by our calculations would make its closest approach to the International Space Station and Discovery on Friday morning ... with an expected radial miss distance of almost 11 kilometers," said Rob Navias, NASA's mission control commentator.
"So although we expect a fairly wide margin of miss distance between this object and the shuttle-station complex, we are continuing to keep an eye on things and will be developing a further course of action over the next 24 hours or so."
The astronauts are following their normal flight plans, moving equipment and supplies into the station from the Leonardo cargo module attached to the forward Harmony module's Earth-facing port.
Astronaut Christer Fuglesang works to transfer equipment from the
Leonardo cargo module. (Photo: NASA TV)
Among the items scheduled for transfer today were two science racks, one devoted to fluid physics and the other to materials science, and an experiment sample freezer. The station astronauts also plan to finish outfitting a new crew sleep station delivered by Discovery and temporarily set up in the Japanese Kibo lab module.
As of this morning, 64 percent of the station supplies and equipment launched in the shuttle's crew cabin had been transferred to the lab complex and 93 percent of the items scheduled for transfer to the crew cabin for return to Earth had been moved. About 18 percent of the 7.5 tons of equipment and supplies launched in the Leonardo module had been transferred to the station.
The flight plan calls for astronauts John "Danny" Olivas and Christer Fuglesang to camp out in the station's Quest airlock module overnight to prepare for a spacewalk Thursday. The goal of the excursion is to install a new ammonia coolant tank and to store a depleted tank, removed during an EVA Tuesday, in the shuttle's cargo bay for return to Earth.
Depending on how the rocket body analysis goes, NASA managers could decide to raise the station's orbit slightly to increase the miss distance. The more likely option, Navias said, would be to do nothing at all.
"At the moment, we do not believe there's any issue involved that would cause us to have to do a debris avoidance maneuver, but we continue to take tracking marks on this piece of space junk and will throughout the course of the day today and overnight while the crew is asleep," he said.
"Basically, there were several options being considered at the start of the crew day several hours ago. But further tracking of this piece of space junk has resulted in (managers) reducing the number of options that we need to be concerned about to just two. One would be to do no maneuver whatsoever, which is the more likely of the two options, or to do a reboost that would occur after the second spacewalk of the mission on Thursday."
If a maneuver is required, it would take place late Thursday, over a period of about three hours, using the shuttle's primary reaction control system thrusters.
Astronaut Michael Barratt moves the COLBERT treadmill into the
space station Tuesday. (Photo: NASA TV)
Here is an updated timeline of today's activity (in EDT and mission elapsed time; includes revision H of the NASA television schedule):
EDT........DD...HH...MM...EVENT 09/02 12:29 PM...04...12...30...Crew wakeup 01:59 PM...04...14...00...ISS daily planning conference 03:44 PM...04...15...45...Fluid science rack transfer 03:49 PM...04...15...50...Crew quarters outfitting 04:44 PM...04...16...45...Materials science rack transfer 05:44 PM...04...17...45...MELFI-2 freezer rack transfer 06:24 PM...04...18...25...PAO event 06:44 PM...04...18...45...Spacesuit swap 07:24 PM...04...19...25...Crew meal 08:24 PM...04...20...25...EVA-2: Tools configured 08:24 PM...04...20...25...MPLM transfers resume 08:29 PM...04...20...30...ISS HTV training 08:30 PM...04...20...31...Mission status briefing on NTV 08:29 PM...04...20...30...Crew quarters activation 09:54 PM...04...21...55...PAO event 10:14 PM...04...22...15...Equipment lock preps 09/03 12:24 AM...05...00...25...EVA-2: Procedures review 01:19 AM...05...01...20...Evening planning conference 02:54 AM...05...02...55...EVA-2: Mask pre-breathe 03:39 AM...05...03...40...EVA-2: Airlock depress to 10.2 psi 03:59 AM...05...04...00...ISS crew sleep begins 04:29 AM...05...04...30...STS crew sleep begins 05:00 AM...05...09...01...Daily highlights reel 10:00 AM...05...10...01...Flight director's update 12:29 PM...05...12...30...Crew wakeup
12:30 AM, 9/2/09: Spacewalk No. 1 ends; all objectives accomplished; space debris impact sites observed
After removing a 1,300-pound ammonia coolant tank, astronauts John "Danny" Olivas and Nicole Stott waited out a storm-triggered communications blackout before successfully retrieving U.S. and European experiment packages mounted on the International Space Station to wrap up a six-hour 35-minute spacewalk.
Running ahead of schedule, the astronauts turned to a few get-ahead tasks that were eventually called off. In the process, however, Olivas reported an unusual number of space debris impact sites on a tool box and the Quest airlock module.
Nicole Stott (upside down) and Danny Olivas work to mount a European
experiment package in the shuttle Discovery's cargo bay for return to
Earth. An ammonia coolant tank removed earlier is visible at top
center, attached to the station's robot arm. (Photo: NASA TV)
"I don't know if you guys are aware of this, but looking at the tool box, there are several MMOD (micrometeoroid/orbital debris) strikes on its face," he said. "I count one, two, three, four, five, six, seven..."
"Yeah, Danny, stay where you are right there and we're going to get a better WVS view," spacewalk coordinator Patrick Forrester radioed from inside Discovery, referring to Olivas' helmet camera.
"Sorry, I left the camera over there."
"That's all right, we can see 'em now, we see one right above the word 'CETA,' a couple below the NASA (logo) meatball," Forrester said.
A few minutes later, Olivas exclaimed, "wow, I'm over here on the top of the airlock, the equipment lock, and there's a pretty good sized MMOD strike on the shield. Do you have video? I can pan back. Also ... one strike on the handrail. I could do this all day."
Inspecting the airlock's micrometeoroid shielding more closely, Olivas said "I count at least three strikes. ... There's a really big one right above the label, too. That one actually sticks out pretty far."
"Houston, copies," Forrester said. "And you're talking about the one right above the alpha there, the A?"
"Yeah, it looks like metal is actually protruding from the surface," Olivas said.
After retrieving a camera, Olivas snapped pictures of the impact sites for analysis on the ground before he and Stott returned to the airlock and ended the excursion at 12:24 a.m.
This was the 131st spacewalk devoted to station assembly and maintenance since construction began in 1998 and the first of three planned for Discovery's mission. Station EVA assembly time now stands at 817 hours and 11 minutes.
The astronauts had no problems of any significance removing the ammonia tank assembly from the station's solar power truss and mounting it on the lab's robot arm where it will remain until a spacewalk Thursday to install a new tank.
At that point, a violent storm swept over a ground station in Guam, interrupting space-to-ground communications from one of NASA's Tracking and Data Relay System satellites for about 33 minutes. When communications were restored, Olivas and Stott pressed ahead with the experiment retrievals.
8:35 PM, 9/1/09: Communications interrupted by bad weather (UPDATED at 9:35 p.m.; storm over Guam, not New Mexico, NASA says
Bad weather at a Guam ground station interrupted communications through one of NASA's Tracking and Data Relay System satellites Tuesday. As a result, space-to-ground communications were interrupted for about a half hour. Spacewalkers Nicole Stott and Danny Olivas were told to delay retrieving two experiment packages until communications can be restored.
"We're going to lose you guys in about a minute and a half, we've lost a TDRS, and we're going to be LOS for 30 minutes, three zero," mission control radioed. "We're going to hold off on the EUTEF and the MISSE items that require the power inhibits, but you can go ahead and do the photos for EUTEF and MISSE during the LOS (loss of signal)."
"We copy," astronaut Patrick Forrester replied from the shuttle Discovery. "We'll do what we can do, look forward to hearing from you in 30 minutes."
NASA originally said the storm blocked communications with a ground station near White Sands, N.M., that normally handles TDRS traffic.
7:40 PM, 9/1/09: Ammonia tank pulled from truss, grappled by station's robot arm
Spacewalkers John "Danny" Olivas and Nicole Stott disconnected and unbolted a 1,300-pound ammonia tank in the space station's solar power truss today and manually held it in place so it could be grappled by the lab's robot arm.
The tank removal went smoothly and other than a bit of concern about an ammonia connector that did not seat as expected following disconnection - and a brief discussion about a torn stitch in one of Olivas' gloves - there were no problems. The station arm grappled the tank at 7:09 p.m.
"Here comes the grapple," called arm operator Kevin Ford. "OK, got it closed and captured, guys."
The 1,300-pound ammonia tank, poised for capture by the
station's robot arm. (Photo: NASA TV)
The view from Danny Olivas' helmet cam, showing the ammonia tank
on the left and astronaut Nicole Stott floating below. (Photo: NASA TV)
With the ammonia tank secured on the station's robot arm, Olivas and Stott will make their way to the European Space Agency's Columbus research module to retrieve a pair of experiments that will be returned to Earth aboard the shuttle Discovery.
5:55 PM, 9/1/09: Spacewalk No. 1 begins
Floating in the space station's Quest airlock module, astronauts John "Danny" Olivas and Nicole Stott switched their spacesuits to battery power at 5:49 p.m. EDT to officially kick off a planned six-and-a-half-hour spacewalk.
Astronaut Nicole Stott backs out of the Quest airlock module while
fellow spacewalker Danny Olivas looks on. (Photo: NASA TV)
After setting up tools and tethers, the astronauts will make their way to the port-one segment of the station's solar power truss on the left side of the U.S. Destiny laboratory module to remove a depleted 1,300-pound ammonia tank from the station's cooling system. A replacement tank will be installed during a second spacewalk Thursday.
01:35 PM, 9/1/09: Astronauts gear up for spacewalk (UPDATED at 3:30 p.m. with updated ammonia tank weights)
Astronauts John "Danny" Olivas and Nicole Stott are gearing up for a planned six-and-a-half-hour spacewalk to remove a massive 1,300-pound ammonia coolant tank from the International Space Station's solar power truss.
While the spacewalk is going on, astronauts inside the station will be moving supplies and equipment into the lab complex from a cargo module delivered by the shuttle Discovery, including a new carbon dioxide removal system, a storage rack, a new astronaut sleep station and a new treadmill named after comedian Stephen Colbert.
"Today's a big transfer day," said space station Flight Director Royce Renfrew. "We're right where we want to be with the transfer ops for this flight."
Flight controllers, meanwhile, implemented an alternative procedure overnight to help maintain the orientation of the shuttle-station "stack" with the station's control moment gyroscopes while nitrogen was vented overboard from the lab's coolant pressurization system in preparation for today's spacewalk.
The station normally would rely on small vernier steering jets aboard the docked shuttle to compensate and maintain the lab's orientation, or attitude, during a propulsive venting, but Discovery's vernier jets suffered a failure after launch and are out of action. Using Russian thrusters for a large maneuver earlier in the mission used up more fuel than expected and engineers implemented an alternative gyro control technique overnight for the nitrogen venting.
"The prop savings was on the order of 50 to 75 kilograms ... using the 'desats enabled" (technique) rather than just using the Russian segment thrusters last night," Renfrew said. "That all worked fine."
Today's spacewalk is the 131st devoted to station assembly and maintenance since construction began in 1998, the 12th so far this year and the first of three planned by Discovery's crew. Going into today's EVA, 90 astronauts and cosmonauts representing the United States, Russia, Canada, Japan, France, Sweden and Germany had logged 810 hours and 36 minutes of station assembly spacewalk time, or nearly 34 days.
For identification, Olivas, call sign EV-1, will be wearing a spacesuit with red stripes around the legs. Stott, EV-3, will be wearing a suit with no stripes.
Stott and Olivas spent the night in the space station's Quest airlock at a reduced pressure of 10.2 pounds per square inch to help purge nitrogen from their bloodstreams and prevent the bends after working in NASA's 5-psi spacesuits.
The primary goals of the excursion are to remove a depleted ammonia tank assembly, or ATA, and attach it to the space station's robot arm for temporary storage. The spacewalkers also will retrieve two experiment packages mounted on the European Space Agency's Columbus lab module. A new ATA charged, with 600 pounds of ammonia and tipping the scales at 1,702 pounds, will be installed during a second spacewalk by Olivas and Christer Fuglesang Thursday and the old tank will be mounted in the shuttle's payload bay for return to Earth.
The old tank would weigh 1,295 pounds on Earth - including 200 pounds of residual ammonia - and is one of the most massive space station components ever handled by spacewalking astronauts.
"In zero G (gravity), we sort of think of everything as being weightless and being easy to move around," said Zeb Scoville, the lead spacewalk officer at JSC. "The thing to remember is that although those things have no weight, they still have mass. ... They're going to have to try to manipulate that mass so it doesn't try to pull them out of their foot restraints. Keeping control of this is certainly a challenge, again because of the mass, the inertia and the fact that it sometimes wants to resist being turned or re-oriented."
Another issue is potential ammonia contamination.
"Before the first spacewalk, the fluid lines that run internal to the ammonia tank and also run from that ammonia tank along the truss structure into the fluid system, a section of that line (was) vented so there will only be residual bits of ammonia inside, there won't be the large pressurization volume of ammonia in those lines when they are demated," Scoville said. "So the amount of ammonia that could potentially leak is limited in that regard.
"If a crew member does get sprayed, we'll have time outside, exposed to the sun, the warm external environment, to bake off any ammonia ice that may be stuck on the suit. Beyond that bake-out scenario, we have some testing hardware once the crew ingresses the airlock. They can do a test at 5 psi that will detect any ammonia that may be off gassing from the suit. So, we'll be able to verify the crew is in a clean configuration before they come inside."
Stott and Olivas will disconnect the old ammonia tank from the port-1 truss segment and pull it out. Holding it in their gloved hands, the astronauts will orient the tank so shuttle pilot Kevin Ford, operating the station's robot arm, can lock on. The tank will remain on the end of the station arm until after the new ammonia tank is installed during the crew's second spacewalk. After that, the old tank will be mounted on a cargo carrier in the shuttle's payload bay for return to Earth, refurbishment and relaunch next year.
"Nicole and Danny have a lot of work to do to disconnect the plumbing and electrical and all that stuff and make sure the (old) tank's vented and everything," Ford said. "It's going to be interesting, they're going to actually hold that tank out there and position it in their hands while I grapple it with the big arm. Then I'll take that away from them and I'll hold onto that until almost the end of EVA-2."
With the old ammonia tank safely locked to the station's robot arm, Stott and Olivas will move to the outboard end of the Columbus module and retrieve two experiment packages, mounting them in Discovery's cargo bay for return to Earth.
While the spacewalk is going on, the station crew will be busy moving supplies and equipment from the Leonardo cargo module into the lab complex, including the storage rack, an astronaut sleep station, the COLBERT treadmill and the new carbon dioxide removal rack.
The space station currently is equipped with four small crew cabins, two in the Russian Zvezda command module, used by commander Gennady Padalka and cosmonaut Roman Romanenko, and two U.S.-built cabins on the port and starboard side of the Harmony module, used by Michael Barratt and Stott. European Space Agency astronaut Frank De Winne uses a temporary sleep station, or TeSS, in the U.S. Destiny laboratory module while Canadian Robert Thirsk bunks in a similar makeshift cabin in the Japanese Kibo module.
Thirsk will use the new NASA crew cabin, which will be temporarily mounted in Kibo and eventually moved to Harmony. A fourth U.S. sleep station will be launched next year and installed in Harmony as well.
The U.S. sleep stations have a volume of 54 cubic feet, about the same as a large refrigerator. They are sound-proofed and feature their own lighting, air ducts, computer ports, communications gear and alarm systems. Eventually arranged in a ring around Harmony, plastic sheathing at the back of each cabin also provides radiation shielding.
"They are very cool," Stott said before launch. "I think it's going to be nice. You show some people the space that's available and they're like, oh my gosh, how could you possibly do that? You think about it, though, it's like this volume that's available to you, it's the whole volume, you're not relying on sticking to a wall somewhere or anything like that. Just like the station in general, you have this whole volume to use."
Here is an updated timeline of today's activity (in EDT and mission elapsed time; includes revision G of the NASA television schedule):
EDT........DD...HH...MM...EVENT 09/01 12:59 PM...03...13...00...Crew wakeup 01:34 PM...03...13...35...EVA-1: 14.7 psi repress/hygiene break 02:24 PM...03...14...25...EVA-1: Airlock depress to 10.2 psi 02:29 PM...03...14...30...ISS daily planning conference 02:44 PM...03...14...45...EVA-1: Campout EVA preps 04:14 PM...03...16...15...EVA-1: Spacesuit purge 04:29 PM...03...16...30...EVA-1: Spacesuit prebreathe 04:29 PM...03...16...30...ISS: Zero G rack transfer 05:19 PM...03...17...20...EVA-1: Crew lock depressurization 05:24 PM...03...17...25...ISS: COLBERT treadmill transfer 05:49 PM...03...17...50...EVA-1: Spacesuits to battery power 05:54 PM...03...17...55...EVA-1: Airlock egress 06:09 PM...03...18...10...EVA-1: Setup 06:34 PM...03...18...35...EVA-1: P1 ammonia tank release 06:44 PM...03...18...45...ISS: Crew quarters rack transfer 08:19 PM...03...20...20...EVA-1: EUTEF retrieval/stow 08:59 PM...03...21...00...ISS: Air rack transfer 10:09 PM...03...22...10...EVA-1/EV-1: MISSE 6 retrieval/stow 10:09 PM...03...22...10...EVA-1/EV-3: Station arm reconfig 10:34 PM...03...22...35...EVA-1/EV-3: MISSE 6 PEC stow 10:59 PM...03...23...00...EVA-1/EV-3: Get aheads 11:39 PM...03...23...40...EVA-1: Cleanup/airlock ingress 09/02 12:19 AM...04...00...20...EVA-1: Airlock pressurization 12:34 AM...04...00...35...Spacesuit servicing 01:44 AM...04...01...45...ISS evening planning conference 03:00 AM...04...03...01...Mission status briefing on NTV 03:59 AM...04...04...00...ISS crew sleep begins 04:29 AM...04...04...30...STS crew sleep begins 05:00 AM...04...05...01...Daily highlights reel 10:00 AM...04...10...01...Flight director's update 12:29 PM...04...12...30...Crew wakeup
6:00 PM, 8/31/09: Shuttle tile assessment continues; no major problems seen; Leonardo cargo module attached to space station; propellant management options studied in wake of shuttle vernier failure (UPDATED at 12:15 a.m. with MPLM hatch opening)
NASA's Mission Management Team met Monday and cleared the shuttle Discovery's nose cap and wing leading edge panels for re-entry as is. An assessment of the shuttle's heat shield tiles is continuing, but there are no signs of any serious problems and engineers hope to wrap up the analysis by Wednesday at the latest.
"We really have a very clean vehicle and the mission's going very well for us," said MMT Chairman LeRoy Cain. "We didn't have too many issues to talk about per se."
Aboard the orbiting shuttle-station complex, meanwhile, astronauts Michael Barratt and Discovery pilot Kevin Ford used the lab's robot arm to carefully pull a 13.5-ton cargo module out of the shuttle's cargo bay for attachment on the Harmony module's Earth-facing port. Unberthing occurred around 4:45 P.M. EDT.
A little more than an hour later, at 5:56 p.m., the Leonardo module was firmly bolted in place. It took several hours to complete leak checks and work to pressurize a vestibule between Harmony and the cargo module, but the astronauts ran ahead of schedule and opened the module at 11:54 p.m., an hour and a half earlier than expected.
The Leonardo MPLM, center, attached to the space station.
(Photo: NASA TV)
The only problem of any significance so far during Discovery's mission is the loss of the shuttle's six vernier steering jets due to a leak in one thruster that was detected after launch.
The vernier jets, two in the shuttle's nose and four in the aft, are normally used during final approach to the space station, to help maneuver the shuttle-station "stack" and maintain the lab's orientation, or attitude. During docking Sunday, commander Frederick Sturckow guided the shuttle to a precision linkup using the ship's larger primary thrusters.
After Discovery's docking to the front end of the station Sunday, however, Russian maneuvering jets were used to yaw the combined 945,000-pound stack 180 degrees, putting the Russian Zvezda command module in the direction of travel and Discovery at the back. The maneuver, normally conducted with the vernier jets, is intended to minimize shuttle heat shield exposure to micrometeoroid impacts.
"The big maneuver that took place after we docked, we had to do that on the Russian segment thrusters because of our loss of verniers," Cain said. "The propellant usage there was more than had been expected or predicted. ... As a result of that, we're going and looking at a lot of the attitude maneuvers and attitude holds we have remaining in the docked mission and seeing what we can do to try and mitigate the use of the Russian thrusters and their propellant."
Russian flight controllers budgeted about 66 pounds of propellant for the entire mission, Cain said, assuming the shuttle's vernier jets would be available.
"We far exceeded that in this one maneuver that we did," he said.
The shuttle's primary thrusters, which generate 870 pounds of thrust when ignited, can be used to maintain the station's orientation when the gyroscopes are not available, but engineers have not yet certified plans to use the big thrusters for the post-docking maneuver or the reverse maneuver before undocking.
"In the simulation runs that were done, there were no issues with structures or contamination of any of the station components or subsystems," Cain said. "The issue with the auto pilot for those larger maneuvers ... was getting into the final attitude. The maneuver would kick off fine, it would proceed fine and progress well. Once it got to the right attitude and was firing thrusters to stop the rates in the various axes is when it was having trouble converging on the final attitude and doing that in a way that was considered controllable."
He said engineers believe the primary jet digital autopilot routines can be fine tuned and "we might end up with a configuration that would be acceptable for us to do this maneuver. Beyond that, there might be an option for us to do the maneuver in this ALT-DAP configuration and when we get close to the final attitude, maybe at that point switch over to one of the other attitude control, attitude hold subsystems."
But that remains to be seen. In the meantime, Cain characterized the shuttle's loss of vernier jets as a relatively minor issue and said that even though more Russian fuel was used than expected after docking Sunday, there was no danger of running out or even running low.
"We have options, and we're looking at the various options because we can," he said. "We're nowhere near any kind of impending issue with the propellant budget on the shuttle or the station in any way at all. It's just we're trying to be smart about what we're doing."
02:00 PM, 8/31/09: Astronauts gear up for cargo module attachment to space station
Space station flight engineer Michael Barratt and shuttle pilot Kevin Ford, operating the lab's big robot arm, geared up Monday to pluck a 13.5-ton cargo module out of Discovery's payload bay for attachment to the station's forward Harmony module.
The astronauts were awakened to begin their third full day in space at 1:30 p.m. EDT by a recording of "Mi Tierra" by Gloria Estefan radioed up from mission control for flight engineer Jose Hernandez, a father of five who became an astronaut after a childhood of migrant farm work.
"Buenos dias," Hernandez called down. "A special good morning to everybody who's listening to us. I want to give a special thanks to my wife, my family and friends who suggested this song. I'm just happy to be able to share my experiences over my Twitter account, a special thanks to those who are following along. Just happy to be here and continuing on with our mission."
As of Monday morning, nearly 25,000 people were "following" Hernandez's updates in English and Spanish.
The Italian-built Leonardo multi-purpose logistics module, or MPLM, is loaded with more than seven tons of equipment and supplies, including two science racks, an experiment sample freezer, a new carbon dioxide removal system, a crew sleep station and a new treadmill named after comedian Stephen Colbert.
If all goes well, Ford and Barratt will unberth Leonardo around 4:10 p.m. and slowly maneuver it into position for attachment to the Earth-facing, or nadir, port on the Harmony module around 5:30 p.m.
Discovery is docked to Harmony's forward port and the distance from the shuttle's cargo bay to the nadir port is relatively short.
"From my perspective, it's just a bit of a rotation," Ford said of the robot arm work. "It's about a ninety-degree rotation and then we'll line it up with the berthing mechanism on the nadir port of the station and we'll just guide it in using some cameras and some mirrors to bring it in about eight centimeters away. And then some hooks will grab it from there."
Sixteen bolts then will be electrically driven in the common berthing mechanism, or CBM, to firmly attach the cargo module to Harmony. The bolt-driving procedure should be complete by around 6:20 p.m.
After that, the astronauts will pressurize the vestibule between Harmony's nadir hatch and Leonardo's, carry out leak checks and connect power, data and cooling lines. Ingress is targeted for around 1:30 a.m. Tuesday.
"Today's the big day for the MPLM, the cargo carrier, that's currently in the payload bay of the orbiter," said station Flight Director Royce Renfrew. "We're going to get that out and put it on the stack today. My team spent the evening last night checking out the port where we're going to install it.
"So today the crew is going to get the MPLM out of the payload bay using the space station's robotic arm, they'll go ahead and take it out and put it up onto the node 2 (Harmony) nadir CBM. Once we can get into the interface there, we'll drive 16 bolts into the interface and make a structural attachment between the MPLM and the ISS. Once we get that done, we'll pressurize the vestibule, the area between the two hatches, make sure that's a good airtight seal, then we'll open the hatches."
Cargo transfer work is scheduled to begin in earnest Tuesday when a materials science rack, the new air revitalization system, the sleep station and the COLBERT treadmill are moved into the station.
While Leonardo's attachment to the station was the highlight of the crew's flight plan Monday, shuttle astronaut John "Danny" Olivas and newly arrived space station flight engineer Nicole Stott planned to check out the equipment they will use during a spacewalk Tuesday, the first of three planned for Discovery's mission.
After an all-hands spacewalk procedures review, Stott and Olivas will end the day camping out in the station's Quest airlock module at a reduced pressure of 10.2 pounds per square inch. The campout procedure is designed to help purge nitrogen from a spacewalker's bloodstream before working in NASA's 5-psi spacesuits.
A Mission Management Team update is scheduled for 4 p.m. and a mission status briefing is on tap at 8:30 p.m.
Here is an updated timeline of today's activity (in EDT and mission elapsed time; includes revision F of the NASA television schedule; abbreviations: SSRMS: station robot arm; MPLM: multi-purpose logistics module):
EDT........DD...HH...MM...EVENT 08/31 01:29 PM...02...13...30...STS/ISS crew wakeup 03:29 PM...02...15...30...ISS daily planning conference 03:39 PM...02...15...40...SSRMS grapples MPLM 04:00 PM...02...16...01...Post-MMT briefing on NTV 04:09 PM...02...16...10...SSRMS unberths MPLM 04:29 PM...02...16...30...ISS locker install 04:34 PM...02...16...35...Middeck transfers 05:29 PM...02...17...30...MPLM installation 05:59 PM...02...18...00...MPLM: 1st stage bolts 06:19 PM...02...18...20...MPLM: 2nd stage bolts 06:29 PM...02...18...30...Post-docking EVA transfers 07:24 PM...02...19...25...Crew meals begin 07:39 PM...02...19...40...SSRMS ungrapples MPLM 08:30 PM...02...20...31...Mission status briefing on NTV 08:34 PM...02...20...35...MPLM vestibule pressurization 09:09 PM...02...21...10...REBA checkout 09:19 PM...02...21...20...SSRMS ops review 09:24 PM...02...21...25...EVA tools configured 09:49 PM...02...21...50...MPLM vestibule readied for ingress 10:29 PM...02...22...30...Univision PAO event 10:54 PM...02...22...55...Equipment lock preps 11:19 PM...02...23...20...MPLM activation (part 1) 09/01 12:54 AM...03...55...00...EVA-1: Procedures review 01:14 AM...03...01...15...MPLM vestibule closeout 01:34 AM...03...01...35...MPLM ingress 01:54 AM...03...01...55...ISS daily planning conference 03:24 AM...03...03...25...EVA-1: Mask/pre-breathe 04:09 AM...03...04...10...EVA-1: Airlock depress to 10.2 psi 04:29 AM...03...04...30...ISS crew sleep begins 04:59 AM...03...05...00...STS crew sleep begins 05:00 AM...03...05...01...Daily highlights 11:00 AM...03...11...01...Flight director update on NTV 12:59 PM...03...13...00...Crew wakeup
09:00 PM, 8/30/09: Shuttle Discovery docks with space station (UPDATED at 10:30 p.m. with quotes from commander; UPDATED at 10:45 p.m. with hatch opening; UPDATED at 12:15 a.m. with comments from flight director)
Shuttle commander Frederick "C.J." Sturckow, forced by a leaky steering jet to use Discovery's big maneuvering thrusters instead of preferred fine-control vernier engines, deftly guided the spaceplane to a flawless docking with the International Space Station Sunday night to cap a two-day rendezvous.
Approaching from directly in front of the laboratory complex as both spacecraft sailed 220 miles above the central Atlantic Ocean at 5 miles per second, the shuttle's payload bay docking port engaged its counterpart on the front end of the statin's Harmony module at 8:54 p.m. EDT, about 10 minutes ahead of schedule.
"Station and Houston, from Discovery, capture confirmed," astronaut Patrick Forrester radioed from the shuttle.
The view from Discovery during final approach to the space station.
The European Columbus module is visible to the left, the Japanese Kibo
module to the right and the Harmony docking port in the center.
(Photo: NASA TV)
Over the next 90-minute orbit, the docking mechanisms locked the two craft firmly together and leak checks were carried out to confirm a tight seal before hatch opening later in the evening.
"Hey Pat, before the hatches get opened there and we have a hard time finding C.J., the orbit one shift wanted to pass along what a great job he did on this first ever vern-failed docking," astronaut Chris Ferguson radioed from mission control. "Did a fantastic job. And you'll be happy to know it occurred on the 25th anniversary of the maiden flight of Discovery. So would you pass that along to him for us?"
"OK, Houston, we appreciate those words and thanks for the great support and the great calls by the ground today, a couple of key saves were made," replied Sturckow, believed to be the first astronaut to make four trips to the space station. "So thank you very much."
Shuttle commander Rick Sturckow leads his crew aboard the space
station. (Photo: NASA TV)
A few minutes later, at 10:33 p.m., hatches were opened and Sturckow, wearing a bright red Marine Corps baseball cap, led his crew into the space station.
"Space shuttle Discovery, arriving," station commander Gennady Padalka said, ringing the ship's bell in the Harmony module.
Padalka and his five station crewmates warmly embraced their seven shuttle colleagues before gathering for a safety briefing and getting down to work.
The primary goals of the mission are to deliver 7.5 tons of science equipment, life support gear and supplies. Nicole Stott, who hitched a ride to the station aboard Discovery, replaced astronaut Timothy Kopra, who plans to return to Earth aboard the shuttle in Stott's place after 57 days in space.
Discovery, docked to the space station. (Photo: NASA TV)
Three spacewalks are planned, overnight Tuesday, Thursday and Saturday, to replace a 1,800-pound ammonia coolant system tank, to retrieve external experiments, deploy a spare parts mounting mechanism and to install wiring needed for a new module scheduled for launch next year.
Before Discovery's arrival, the 83-percent-complete space station massed 699,010 pounds. At docking, the combined spacecraft massed nearly a million pounds.
Discovery's approach to the space station was the first ever conducted using the shuttle's big primary reaction control system maneuvering thrusters, which generate 870 pounds of thrust when ignited. Shuttle commanders normally rely on six small 24-pound-thrust vernier jets - two in the nose and four in the shuttle's aft - to precisely control the final rendezvous sequence.
The shuttle Discovery, as seen from the space station,
beginning its final approach. (Photo: NASA TV)
But one of Discovery's two forward vernier jets failed after launch overnight Friday, forcing flight controllers to close a manifold that isolated both forward thrusters. As a result, Sturckow had to complete the rendezvous using the larger primary jets instead.
Shuttle astronauts routinely train for dockings using an alternate digital autopilot mode, but Sturckow was the first to fly such a "no-vernier" approach in practice.
Trailing the station by 9.2 miles, Sturckow and Ford fired the shuttle's left orbital maneuvering system rocket at 6:26 p.m. to begin the final phase of the rendezvous.
At 8:03 p.m., with the shuttle positioned about 600 feet directly below the station, Sturckow used the primary jets to kick off a slow nine-minute back-flip maneuver to expose the shuttle's belly to the space station.
As it pitched around at a sedate three quarters of a degree per second, Padalka and Michael Barratt, using digital cameras equipped with 400-mm and 800-mm lenses, photographed the shuttle's heat shield to help engineers assess its health before re-entry.
Discover completes the rendezvous pitch maneuver
crossing the coast of New Zealand. (Photo: NASA TV)
After the flip maneuver, Sturckow flew Discovery in an arc up to a point about 400 feet directly in front of the station. From there, he manually guided the spaceplane in for docking.
"With the verniers, you have finer control with the smaller jets, you could tell he had to fly it a little bit different," said lead Flight Director Tony Ceccacci. "For one instance, it would add more closing rate in and he'd have to brake to make sure his closing rates weren't too high. In other situations, he had to add closing rate.
"So it was just a little bit more complicated as far as where he had to do these different tasks and such than he would if he had verniers. Again, the crew has trained this. Yesterday, we had a discussion with C.J., what the critical points were, and he just flew it like a champ today."
6:30 PM, 8/30/09: Shuttle crew begins final phase of station rendezvous
Trailing the International Space Station by about 9.2 miles, shuttle commander Frederick "C.J." Sturckow and pilot Kevin Ford fired the shuttle's left orbital maneuvering system rocket engine at 6:26 p.m. to begin the final phase of a complex rendezvous.
The 11-second rocket firing changed Discovery's velocity by just 6.1 mph, kicking off an approach sequence that should bring the shuttle to a point 600 feet directly below the space station around 8 p.m.
5:15 PM, 8/30/09: Preliminary assessment indicates shuttle tank performed well during launch; no major foam loss seen; loss of vernier jets for station rendezvous a shuttle first, but managers say backup plans in place
The shuttle Discovery's external tank appears to have performed well during the ship's launch overnight Friday. While engineers will not complete a detailed analysis for several more days, no major problems or foam loss have been seen so far in NASA's initial looks at ascent imagery and other data.
Commander Rick Sturckow (left), pilot Kevin Ford and flight
engineer Jose Hernandez carry out a rendezvous rocket firing
Saturday in preparation for today's docking.
(Photo: NASA TV)
"The launch and the ascent was just beautiful and the performance of the vehicle was exceedingly good," LeRoy Cain, chairman of NASA's Mission Management Team, told reporters Sunday. "We're safely on orbit, the crew is preparing for rendezvous and docking later this afternoon and evening and we're looking forward to that."
Shuttle commander Frederick "C.J." Sturckow will be flying the final approach to the station Sunday evening using the shuttle's big primary reaction control system thrusters, or PRCS jets, instead of less-powerful vernier jets. Two 24-pound-thrust vernier rocket engines are available in a nose-mounted rocket pod while four are available in the aft.
But the right-firing forward vernier jet failed shortly after launch, forcing flight controllers to close a manifold and isolate both forward thrusters. As a result, Sturckow will be making NASA's first space station rendezvous and docking carried out with the larger 870-pound-thrust primary maneuvering rockets.
"At this point, vernier thrusters are not available to us," Cain said. "We do have a couple of backup modes to the verniers and so it's really not a problem for us to use the other thrusters for attitude control and for maneuvers. ... The crew is very well trained for this particular failure mode, they've trained it numerous times. And so we don't have any concerns for that."
Using what's known as the ALT-DAP, or alternate digital autopilot mode, the shuttle's flight computers will fire the primary jets as required to maintain Discovery's orientation in space while Sturckow, flying the shuttle from the aft flight deck, will use the big thrusters to move in for docking around 9:04 p.m.
"I would characterize it as being slightly more challenging, simply because of the different autopilot modes the crew trains to and flies with," Cain sad. "They've certainly done more training where we have vernier autopilot mode available to us than cases where they don't have it."
Once docked, the orientation of the combined shuttle-station "stack" will be maintained primarily by the station's control moment gyroscopes and Russian rocket thrusters. The shuttle's vernier jets normally are used to supplement the gyros, but that option is not available this time around.
"It's a pretty sophisticated DAP mode where based on moments of inertia, the DAP can figure out which jets to fire individually to maintain attitude control and to do maneuvers," Cain said. "We have both of those modes for shuttle flying alone. Once we're docked, we do have the ability to use ALT-DAP for attitude hold (but) it's lower priority than some of the other modes for handling attitude for shuttle station combined."
During the shuttle Endeavour's launching in July, an unusual amount of foam insulation fell away from the central intertank region of the ship's external tank. In addition, a piece of foam separated from an ice-frost ramp on the upper liquid oxygen section, the second flight in a row to experience that problem.
Discovery's flight was delayed while engineers conducted extensive tests to make sure the next two tanks in the launch sequence were in good shape. Cain said based on a very preliminary look at the data, the intertank foam and the ice-frost ramps on Discovery's tank suffered no major losses.
"From what I've been told, what we have seen is what we consider to be normal kind of erosion on a couple of the ice-frost ramps on the LOX tank," Cain said. "Don't see any losses, if you will, on the ice-frost ramps, nothing like on (the last two missions) where we had losses on the 718 IFR. So that looked really good to us."
Likewise, "the intertank looked very good. As you know, we had several areas of losses from the interank on the previous mission and the intertank (on Discovery's tank) looked very good. We had one loss that I believe was in the intertank flange area, so the folks will be looking at that. ... But that would be very much in family with what we've been seeing on all these missions."
03:00 PM, 8/30/09: Shuttle Discovery closes in on space station
The shuttle Discovery, marking the 25th anniversary of its maiden launch in 1984, closed in on the International Space Station Sunday, on course for a docking around 9:04 p.m. EDT.
Trailing the shuttle by about 9.2 miles, commander Frederick "C.J." Sturckow and pilot Kevin Ford plan to begin the final phase of the rendezvous with a rocket firing at 6:25 p.m.
Approaching from behind and below, Sturckow will pause the approach around 8:02 p.m. at a distance of 600 feet directly below the space station. In a now-routine maneuver, Discovery will perform a slow back-flip, allowing the space station crew to photograph the heat shield tiles on the ship's belly with powerful telephoto lenses.
Those pictures will be downlinked to engineers at the Johnson Space Center in Houston, who are assessing launch-day imagery and laser scans from an inspection by the astronauts Saturday to look for any signs of ascent impact damage. So far, there are no indications of any problems with Discovery's heat shield.
After pausing for the rendezvous, or rotational, pitch maneuver, Sturckow plans to guide Discovery in an arc up to a point about 400 feet directly in front of the space station with the shuttle's nose pointing toward space and its open payload bay facing a docking port on the front end of the Harmony module.
From there, he plans to manually guide the spaceplane to a docking with the 700,000-pound station at 9:04 p.m.
"We'll march right in on the v-bar (velocity vector) from about 400 feet in, controlling our closure the whole way," Ford said in a pre-launch interview. "At that point, C.J. is just looking out the overhead window and through the centerline camera and he'll just make inputs so that as we get closer and closer, we'll fly a tighter and tighter tolerance until we're down to a 3-inch tolerance at the end and about a decimal-one-foot per second closure rate as we fly into the capture mechanism.
"It is pretty dynamic and the center of gravity of the space shuttle is well below where the docking port is so there's a time where there's a little bit of what we call 'ringing' going on where the motions ... are kind of ringing out. There are dampers on the docking mechanism that will kill all that motion finally."
The only issue going into today's docking procedure was the loss of small vernier steering jets due to a leaking forward thruster that was isolated Saturday. While the small thrusters are useful during docking and later, to help control the attitude, or orientation, of the space station, Sturckow and his crewmates have trained to make the approach using more powerful primary thrusters and flight controllers don't expect any problems.
"WeÕll start off by doing a series of burns that will adjust our trajectory to get on the proper profile and then, after that, we will have the manual phase, we'll take over and fly from the aft flight deck of the shuttle," Sturckow said in a NASA interview. "We'll fly up underneath the space station and then perform the RPM, the R-bar pitch maneuver where we'll expose the belly of the space shuttle to the station so they can image it with cameras up there, the station crew can, to make sure all the tiles are in good shape. After that, we'll fly out in front of the station and then fly in on what we call the v-bar approach, fly in and dock with the space station."
Sturckow, Ford, flight engineer Jose Hernandez, Patrick Forrester, John "Danny" Olivas, European Space Agency astronaut Christer Fuglesang and incoming space station flight engineer Nicole Stott will be welcomed aboard by Expedition 20 commander Gennady Padalka, Michael Barratt, Timothy Kopra, cosmonaut Roman Romanenko, European Space Agency astronaut Frank De Winne and Canadian astronaut Robert Thirsk.
After a brief safety briefing to familiarize the shuttle astronauts with station operations, the crews will split up and get to work, beginning the transfer of equipment and supplies to the station and using the lab's robot arm to pluck Discovery's heat shield inspection boom from the ship's cargo bay and hand it off to the shuttle's robot arm.
Stott, who is replacing Kopra aboard the station, will help move her custom Soyuz seat liner to the station. Once it is in place, she will become a member of the space station's Expedition 20 crew and Kopra will join Discovery's crew. Assuming an on-time landing Sept. 10, Kopra will have logged 57 days in space since launch July 15 aboard the shuttle Endeavour.
A mission status briefing is planned for 12 a.m. Monday. Here is an updated timeline of today's activity (in EDT and mission elapsed time; includes revision F of the NASA television schedule):
EDT........DD...HH...MM...EVENT Flight Day 3 (Updated 08/30/09) 08/30 01:29 PM...01...13...30...00...STS/ISS crew wakeup 02:59 PM...01...15...00...00...ISS daily planning conference 03:09 PM...01...15...10...00...Group B computer powerup 03:29 PM...01...15...30...00...Rendezvous timeline begins 04:00 PM...01...16...01...00...Post-MMT briefing on NTV 04:19 PM...01...16...20...00...Spacesuits removed from airlock 04:53 PM...01...16...54...19...NC-4 rendezvous rocket firing 06:26 PM...01...18...26...40...TI burn 07:02 PM...01...19...02...40...Sunset 07:04 PM...01...19...04...40...Range: 30,000 feet 07:08 PM...01...19...08...23...U.S. arrays feathered 07:24 PM...01...19...25...16...Range: 10,000 feet 07:28 PM...01...19...28...23...ISS maneuver start 07:33 PM...01...19...33...23...ISS in docking attitude 07:33 PM...01...19...33...56...Range: 5,000 feet 07:33 PM...01...19...33...58...Sunrise 07:39 PM...01...19...39...25...Range: 3,000 feet 07:43 PM...01...19...43...34...MC-4 rendezvous burn 07:47 PM...01...19...47...34...Range: 1,500 feet 07:48 PM...01...19...49...12...RPM start window open 07:52 PM...01...19...52...34...Range: 1,000 feet 07:55 PM...01...19...55...34...KU antenna to low power 07:56 PM...01...19...56...34...+R bar arrival directly below ISS 08:01 PM...01...20...01...46...Range: 600 feet 08:03 PM...01...20...03...40...Start pitch maneuver 08:03 PM...01...20...04...08...Noon 08:10 PM...01...20...11...04...RPM full photo window close 08:11 PM...01...20...11...40...End pitch maneuver 08:13 PM...01...20...14...16...Initiate pitch up maneuver (575 ft) 08:19 PM...01...20...19...30...RPM start window close 08:25 PM...01...20...25...46...+V bar arrival; range: 310 feet 08:26 PM...01...20...26...36...Range: 300 feet 08:30 PM...01...20...30...46...Range: 250 feet 08:33 PM...01...20...34...18...Sunset 08:34 PM...01...20...34...56...Range: 200 feet 08:37 PM...01...20...37...26...Range: 170 feet 08:38 PM...01...20...39...06...Range: 150 feet 08:42 PM...01...20...43...16...Range: 100 feet 08:45 PM...01...20...46...16...Range: 75 feet 08:50 PM...01...20...50...26...Range: 50 feet 08:53 PM...01...20...53...46...Range: 30 feet; start stationkeeping 08:58 PM...01...20...58...46...End stationkeeping; push to dock 09:02 PM...01...21...03...06...Range: 10 feet 09:04 PM...01...21...04...47...DOCKING 09:05 PM...01...21...05...30...Sunrise 09:29 PM...01...21...30...00...Leak checks 09:59 PM...01...22...00...00...Orbiter docking system prepped for ingress 10:04 PM...01...22...05...00...Group B computer powerdown 10:29 PM...01...22...30...00...Post docking laptop reconfig 10:29 PM...01...22...30...00...Hatch open 10:59 PM...01...23...00...00...Welcome aboard! 11:09 PM...01...23...10...00...Safety briefing 11:34 PM...01...23...35...00...Middeck transfers begin 11:34 PM...01...23...35...00...Soyuz seatliner transfer/installation 11:44 PM...01...23...45...00...SSRMS grapples OBSS 08/31 12:00 AM...02...00...01...00...Mission status briefing on NTV 12:14 AM...02...00...15...00...SSRMS unberths OBSS 12:44 AM...02...00...45...00...Soyuz seat line installed 01:04 AM...02...01...05...00...ISS: Sokol suit leak checks 01:44 AM...02...01...15...00...SSRMS hands OBSS to SRMS 01:49 AM...02...01...50...00...Playback ops 02:29 AM...02...02...30...00...ISS evening planning conference 04:59 AM...02...05...00...00...ISS crew sleep begins 05:29 AM...02...05...30...00...STS crew sleep begins 06:00 AM...02...06...02...00...Daily highlights reel on NTV 12:00 PM...02...12...01...00...Flight director's update 01:29 PM...02...13...30...00...Crew wakeup
1:25 AM, 8/30/09: Astronauts inspect heat shield, check out spacesuits, ready shuttle for docking Sunday night; leaky thruster no threat to docking
The Discovery astronauts conducted an inch-by-inch inspection of the most critical sections of the shuttle's heat shield Saturday, examining the ship's nose cap and wing leading edge panels with a laser scanner on the end of a 50-foot-boom attached to the shuttle's robot arm.
No obvious problems stood out, but it will take engineers several more days to complete the normal post-Columbia assessment of launch imagery, the laser scans carried out Saturday and close-up photos of Discovery's belly during final approach to the International Space Station Sunday evening before the heat shield is given a clean bill of health.
Lead Flight Director Tony Ceccacci briefs reporters
on flight day two activities. (Credit: NASA TV)
Docking with the International Space Station is targeted for around 9:04 p.m. EDT Sunday. As with all shuttle-station dockings, commander Frederick "C.J." Sturckow will approach from directly in front of the lab complex, manually guiding the shuttle the final 400 feet or so to a linkup with a port on the front end of the Harmony module.
But Sturckow will have an added challenge Sunday. He won't be able to use the shuttle's small vernier jets for fine attitude control because of an apparent leak in one of two small thrusters in the ship's nose. Because of the presumed leak, engineers asked the crew to close a manifold earlier Saturday to isolate the leak, taking both forward jets off line for the duration of the mission.
"We had one of our vernier jets, F5R, fail-leak last evening," lead flight director Tony Ceccacci told reporters early Sunday. "Basically, the signatures that we saw were somewhat interesting, I have to admit. I was an ex prop (propulsion officer in mission control) and what I saw didn't quite make sense. But what we did this morning after the crew woke up, we did close that manifold, No. 1, just to safe the system. We wanted to make sure the manifold was evacuated and didn't cause any contamination concerns to the station.
"Even in the loss-of-vernier case, the crew is well trained to press through the rendezvous sequence, the prox ops (proximity operations) part of it. We actually had a quick tag up with C.J. today on what to expect and what differences he will have without vernier jets."
The shuttle's forward reaction control system, or RCS, includes 14 primary engines and two vernier jets. Two aft RCS pods feature 12 primary thrusters and two verniers each. The primary engines generate 870 pounds of thrust while the verniers produce just 24 pounds of push.
Without the verniers, "the crew just has to be a little bit more careful," Ceccacci said. Using the more powerful primary jets during final approach requires "just a little bit more piloting" than usual, "but nothing that's outside of our experience or what we train the crew."
Once docked, the orientation, or attitude, of the combined shuttle-station "stack" is typically controlled by the station's four control moment gyroscopes, assisted from time to time by the shuttle's vernier jets. Because of the F5R failure, Russian thrusters will be used for major changes.
"There were some other things we were looking at in the event we had to do a debris avoidance maneuver, what the best scenario and configuration would be, whether it would be on the Russian thrusters or going to the alt-DAP (digital autopilot) on the primary jets," Ceccacci said. "The folks are taking a look, making sure we have good solar array configurations, making sure that we meet all the loads constraints and such. But we have work-arounds to deal with that failure."
Along with inspection the nose cap and wing leading edge panels Saturday, the Discovery astronauts checked out two spacesuits that will be used later in the mission by John "Danny" Olivas and Christer Fuglesang. Early Sunday, the crew planned to test their rendezvous tools and prepare the orbiter docking system for operation before going to bed at 5:29 a.m.
2:45 PM, 8/29/09: Astronauts gear up for heat shield inspection
The Discovery astronauts faced a routine-but-busy first day in space Saturday, inspecting the shuttle's heat shield, checking out their spacesuits and readying the ship for docking Sunday with the International Space Station.
The astronauts were awakened at 2:29 p.m. EDT with a recording of "Back in the Saddle Again" by Gene Autry, beamed up by mission control from commander Rick Sturckow's family.
"Good morning, Houston," Sturckow radioed. "It's great to be back in space and we're looking forward to a great flight day two."
The major item on the agenda is to inspect the shuttle's reinforced carbon carbon nose cap and wing leading edge panels, which experience the most extreme heating during re-entry, to look for any signs of ascent impact damage.
A NASA graphic showing a heat shield inspection boom on the end of
shuttle Discovery's robot arm. (Credit: NASA TV)
Television views from a camera mounted on the side of Discovery's external tank did not show any obvious signs of significant debris from falling foam insulation or any other source, but it will take engineers several days to evaluate launch photography, laser scans today using a boom on the end of Discovery's robot arm and photographs of the shuttle's belly during final approach to the space station Sunday.
Today's inspection is "our opportunity to look at the leading edge of the wings, the RCC, the nose cap of the space shuttle and some of the area underneath for damage, in case we should have lost some foam or something else that impacted the shuttle," said astronaut Patrick Forrester.
"We use the robotic arm from the shuttle, along with the boom that we have now started carrying on the starboard side of the shuttle, and basically we run through a series of automated sequences with that robotic arm. That data is recorded and sent to the ground where the folks down there will evaluate it to see if there is any damage.
"ItÕs a very detailed process that we go through," he said. "ItÕs a thorough process that we go through and we have a lot of confidence now that we can determine any damage that the shuttle might have. My role as the lead robotics person on the shuttle side is to kind of spearhead that, but IÕll be doing it with Kevin Ford and Jose Hernandez. Over the period of flight day two (Saturday), the three of us will rotate through the roles of flying the arm, doing clearance with the boom on the shuttle and also just monitoring the monitors and the tapes and the other processes that we do."
A mission status briefing is planned for midnight. Other than a leaking steering jet, there are no technical problems of any significance aboard Discovery. Flight controllers say the lost steering jet was isolated and will have no impact on the shuttle's mission.
Here is an updated timeline of today's activity (in EDT and mission elapsed time; includes revision E of the NASA television schedule):
EDT........DD...HH...MM...EVENT 08/29/09 02:29 PM...00...14...30...Crew wakeup 05:00 PM...00...16...59...NC-2 rendezvous rocket firing 05:04 PM...00...17...05...Shuttle arm (SRMS) unberths OBSS 05:19 PM...00...17...20...Ergometer setup 05:19 PM...00...17...20...Laptop setup (part 2) 05:49 PM...00...17...50...Spacesuit checkout preps 06:19 PM...00...18...20...Spacesuit checkout 06:19 PM...00...18...20...OBSS starboard wing survey 08:04 PM...00...20...05...Crew meals begin 09:04 PM...00...21...05...OBSS nose cap survey 09:54 PM...00...21...55...OBSS port wing survey 11:04 PM...00...23...05...Spacesuit prepped for transfer to station 11:54 PM...00...23...55...SRMS berths OBSS 08/30 12:00 AM...01...00...01...Mission status briefing on NTV 12:34 AM...01...00...35...Heat shield laser scan downlink 01:34 AM...01...01...35...Rendezvous tools checkout 01:49 AM...01...01...50...Centerline camera setup 01:59 AM...01...02...00...NC-3 rendezvous rocket firing 02:19 AM...01...02...20...Orbiter docking system ring extension 05:29 AM...01...05...30...Crew sleep begins 06:00 AM...01...06...01...Daily highlights reel 01:29 PM...01...13...30...Crew wakeup
12:15 AM, 8/29/09: Shuttle Discovery roars into space
Running four days late, the shuttle Discovery roared to life and shot into space late Friday, lighting up the night sky with a rush of fire as it set off on a 13-day mission to deliver 7.5 tons of supplies and equipment to the International Space Station.
With commander Frederick "Rick" Sturckow and pilot Kevin Ford monitoring the computer-controlled ascent, Discovery's twin solid-fuel boosters ignited at 11:59:37 p.m. EDT, kick-starting the crew's eight-and-a-half-minute ride to orbit with a rush of 5,000-degree flame.
The shuttle Discovery blasts off. (Photo: NASA TV)
Taking off at roughly the moment Earth's rotation carried launch pad 39A into the plane of the space station's orbit, Discovery quickly climbed above its service gantry, rolled about its long axis and thundered away on a trajectory paralleling the East Coast.
Discovery's launching came four days after a scrub Tuesday because of bad weather and back-to-back delays caused by concern about an 8-inch hydrogen valve in the shuttle's engine compartment.
The shuttle was cleared for launch late Friday after tests showed the valve was working normally. NASA managerrs approved a waiver in case of additional trouble, but the valve closed on command during fueling and there were no other problems.
Including the weather. Despite clouds and threatening storms to the south, conditions improved as launch time approached and the shuttle was cleared for flight.
Visible for hundreds of miles around, Discovery put on a spectacular show for area residents and tourists as it raced across the sky atop twin pillars of fire from its giant boosters.
A tracking camera locked onto the shuttle's boosters and
main engines. (Photo: NASA TV)
Two minutes after liftoff, their propellant expended, the boosters dropped away and Discovery continued toward orbit under the power of its three main engines, a brilliant "star" rivaling Venus in brightness as it streaked toward the horizon.
During the shuttle Endeavour's launching July 15, an unusual amount of foam insulation fell from the ship's external tank. While Endeavour's heat shield suffered no major impact damage, NASA managers ordered extensive testing to make sure Discovery's tank was safe to launch.
Live television views from a camera mounted on the side of the giant tank showed nothing obvious falling away as the shuttle accelerated out of the dense lower atmosphere.
But it will take several days for engineers to determine the health of Discovery's heat shield based on a thorough assessment of launch photography, data collected by the crew in orbit and close-up photos of the shuttle's belly during final approach to the space station.
Shuttle Discovery separates from its external tank.
(Photo: NASA TV)
In any case, by the time Discovery's boosters were jettisoned the shuttle was climbing out of the dense lower atmosphere, which can impart high impact velocities, and the remainder of the shuttle's ascent was uneventful.
Six-and-a-half minutes after booster separation, Discovery's main engines shut down and the shuttle slipped into its planned preliminary orbit. If all goes well, Sturckow will guide the orbiter to a docking with the International Space Station around 9 p.m. Sunday.
Along with replacing a 1,800-pound ammonia coolant tank in the station's main power truss during their first two spacewalks, the astronauts will deliver two sophisticated science racks, one devoted to fluid physics and the other to materials science, an experiment sample freezer, a new air revitalization rack, a crew sleep station and a treadmill named after comedian Stephen Colbert.
The "Combined Operational Load Bearing External Resistance Treadmill," or COLBERT, received its name after the comedian launched a successful tongue-in-cheek write-in campaign to name a final station module in his honor. NASA managers declined, naming the new module Tranquility instead, but renamed the treadmill after Colbert.
"I was still honored to receive the traditional NASA consolation prize, a space treadmill," Colbert said in a taped message to NASA. "I couldn't be prouder that my treadmill will soon be installed on the International Space Station to help finally slim down all those chubby astronauts."
Along with delivering needed supplies and equipment, astronaut Nicole Stott will replace space station flight engineer Timothy Kopra, launched to the lab complex in July and returning to Earth in Stott's place.
Remaining behind when Discovery departs, Stott will join Expedition 20 commander Gennady Padalka, NASA flight engineer Michael Barratt, cosmonaut Roman Romanenko, Canadian Robert Thirsk and European Space Agency astronaut Frank De Winne as a member of the station's full-time crew.
Discovery's flight is the last shuttle mission that will rotate space station crew members. While Stott will ride a shuttle home in November, future station crew members will travel up and down aboard Russian Soyuz capsules. NASA is paying the Russian space agency roughly $50 million per seat while the U.S. agency closes out shuttle operations and works to develop a replacement spacecraft not expected to fly until 2015 at the earliest.
Only six shuttle flights are planned after Discovery's mission, all of them devoted to finishing the space station and loading it with supplies, spare parts and other equipment to protect against failures after the shuttle fleet is retired.
Launching enough supplies and equipment to support a full-time crew of six is a major challenge and one that Stott will face right away. She will be responsible for operating the station's robot arm to capture and attach an unmanned Japanese supply ship being prepared for its maiden launch Sept. 10. If all goes well, Stott will pluck the HTV craft out of orbit Sept. 17 and dock it to the Harmony module's Earth-facing port.
Discovery's flight is equally critical to maintaining a permanent presence in space. Along with delivering science hardware and life support equipment, the shuttle crew also will bring up 1,600 pounds of food and other supplies, including carbon dioxide-absorbing lithium hydroxide canisters, used to supplement the station's U.S. and Russian CO2 scrubbers.
"We're bringing up seven racks that will be transferred to the space station," said European Space Agency astronaut Christer Fuglesang, making his second shuttle flight. "Three of them are really to keep the station's six crew members well and alive. There's a crew quarters, a treadmill - you have to exercise twice a day if you stay in space up to six months - and then there's a system to keep the air clean. Then we're bringing up three racks dedicated to science. And of course, there's a lot of food and other things."
Sturckow, Ford, Fuglesang and Stott were joined aboard Discovery by Jose Hernandez, John "Danny" Olivas and Patrick Forrester. Ford, Hernandez and Stott are space rookies making their first flight. Sturckow is a three-flight veteran, Forrester has two previous missions to his credit while Olivas and Fuglesang each have one.
With Discovery's arrival, the space station will once again be home to an international crew of 13, a record first set during Endeavour's July mission
"As we transition to six-person crew, there's a big step up in terms of consumables," said Kirk Shireman, deputy manager of the space station program at the Johnson Space Center. "And this flight will really get us in a robust configuration for keeping six-person crew and to fully utilize the ISS.
"We're launching about 1,590 pounds of crew supplies, that's food and other things to keep the crew alive and happy, we're launching 6,190 pounds of what I call vehicle hardware, and this is things in preparation for assembly, spares, those kinds of things. And we're launching over 6,050 pounds of utilization hardware. That's several racks and payloads themselves. So it's a big flight to fully utilize the International Space Station."
Three spacewalks are planned during Discovery's visit, one by Olivas and Stott on Tuesday and two by Olivas and Fuglesang Thursday and next Saturday. If all goes well, Discovery will undock from the space station Sept. 8 and land back at the Kennedy Space Center around 7:10 p.m. on Sept. 10.
8:45 PM, 8/28/09: Astronauts strap in for launch
The Discovery astronauts began strapping in aboard the space shuttle around 8:40 p.m. to await liftoff on a space station resupply mission. NASA managers are hopeful the weather will cooperate, but the outlook is uncertain, with forecasters on the lookout for electrically charged anvil clouds from storms to the southeast.
The Discovery astronauts pose for photographers and well wishers
before heading to pad 39A to strap in for launch. (Photo: NASA TV)
There are no technical problems of any significance at pad 39A and liftoff remains on track for 11:59:37 p.m.
"We're working no technical issues and our weather forecast is getting more optimistic as the evening progresses," said launch commentator Mike Curie.
Commander Rick Sturckow straps in aboard Discovery.
(Photo: NASA TV)
Nicole Stott, bound for the International Space Station,
makes her way to a lower-deck seat. (Photo: NASA TV)
4:25 PM, 8/28/09: Hydrogen inboard fill-and-drain valve closes normally; fueling continues
The 8-inch hydrogen fill-and-drain valve in the shuttle Discovery's engine compartment responsible for back-to-back launch scrubs earlier this week closed normally today as the ship's external tank neared a full load of propellant.
With the valve confirmed in the closed position, there is no need to exercise a waiver that would have allowed engineers to cycle the valve to ensure it was properly seated. There are no other technical problems of any significance and launch remains on track for 11:59:37 p.m., weather permitting.
2:50 PM, 8/28/09: Mission Management Team clears shuttle Discovery for Friday night launch try
NASA's Mission Management Team cleared the shuttle Discovery for a fourth launch try Friday night, approving a waiver to pre-launch flight rules allowing engineers to cycle a liquid hydrogen valve, if necessary, to confirm it is closed.
Launch is targeted for 11:59:37 p.m. EDT, roughly the moment Earth's rotation carries the launch pad into the plane of the International Space Station's orbit.
Shuttle Discovery, poised atop pad 39A. (Photo: NASA TV)
Fueling was scheduled to begin at 2:34 p.m., but it was held up about 10 minutes because of concern about the possibility of lightning within five nautical miles of the launch pad. The forecast for launch calls for a 40 percent chance of unacceptable weather, with a chance of thunderstorms within 20 nautical miles.
Discovery's crew - commander Frederick Sturckow, pilot Kevin Ford, flight engineer Jose Hernandez, Patrick Forrester, John "Danny" Olivas, European Space Agency astronaut Christer Fuglesang and space station flight engineer Nicole Stott - plans to begin strapping in around 8:40 p.m., weather permitting.
Discovery's initial launch try early Tuesday was called off due to stormy weather near the launch pad. A second attempt was called off during fueling Tuesday night for a Wednesday morning launch when an 8-inch liquid hydrogen fill-and-drain valve in the shuttle's engine compartment failed to indicate it was closed.
NASA flight rules prohibited engineers from cycling the valve under cryogenic conditions out of a concern about a possibly unknown problem that could cause it to fail in the closed position, making it difficult to drain the tank after a delay. Launch was tentatively rescheduled for early Friday.
During tests Wednesday night, after Discovery's tank was drained, the valve and its position indicator both worked normally, cycling open and closed five times at ambient temperatures. A pressure decay test also indicated the valve closed normally.
Discovery had two launch opportunities Friday roughly 23-and-a-half hours apart. During an MMT meeting Thursday, NASA managers opted to pass up the first opportunity in favor of the second to give engineers more time to review the valve issue.
During today's meeting, a waiver was processed that will allow engineers to cycle the valve twice during fueling, if required, to confirm closing. In addition, engineers developed plans to use alternate cues to verify the valve's position.
The MMT also discussed a hydraulic system failure Thursday that delayed the test firing of a new five-segment solid-fuel booster intended for use in post-shuttle rockets. The hydraulic system in the test rocket is virtually identical to equipment used by Discovery's solid-fuel booster, but NASA managers found no problems with the shuttle hardware and cleared Discovery for flight.
12:15 PM, 8/27/09: LAUNCH SCRUBBED to no earlier than Friday night to collect additional data (UPDATED at 6:25 p.m. with news briefing)
NASA managers Thursday ordered another delay for launch of the shuttle Discovery, from early Friday morning to late Friday night, to give engineers additional time to make sure an 8-inch hydrogen valve in the orbiter's aft compartment will operate normally during fueling.
NASA's Mission Management Team plans to meet at noon Friday to review the work, consider a waiver to flight rules governing how the valve system operates and make a final decision on whether to clear Discovery for fueling and launch at 11:59:39 p.m. EDT. Forecasters are calling for a 60 percent chance of acceptable weather at launch time.
Discovery is bound for the International Space Station, carrying a crew of seven and more than 7.5 tons of supplies and equipment. Because the space station launch window moves about 23 minutes earlier per day, Discovery has two launch opportunities Friday, the first at 12:22 a.m. and the second at 11:59 p.m. The MMT on Thursday gave up the first opportunity in favor of the second.
"First off, just to put the right spin on it, we're here to not talk about a scrub, in fact we're still going to launch on Friday," MMT Chairman Mike Moses joked during a news briefing Thursday.
The problem cropped up during fueling Tuesday for a day-late launching Wednesday morning. As Discovery's external tank was filled with liquid oxygen and hydrogen rocket fuel, the inboard hydrogen fill-and-drain valve was commanded to close. Data from a position sensor never indicated the valve was, in fact, closed and NASA managers called off the countdown.
They were responding to a flight rule that prohibited real-time troubleshooting under supercold cyrogenic conditions out of concern a valve already near failure might break in the closed position, making it extremely difficult to drain the huge fuel tank after a launch delay.
After Discovery's tank was drained, engineers tested the valve under ambient conditions late Wednesday and in five complete cycles, the valve - and the position indicator - worked normally.
Engineers restarted Discovery's countdown early Thursday in hopes of getting clearance to proceed to an early Friday launch. But the Mission Management Team ordered another delay to give the engineers time to rest and complete the complex analysis without being under the pressure of a countdown.
"The teams have been working really hard over the last several days," Moses said. "We got some test data last night, that came in fairly late in the afternoon or evening timeframe, the teams went off and talked about what that data meant, we talked about some possible forward plans.
"They got back together this morning and it became pretty apparent pretty quick we had really good rationale, we had a really good story, but the teams that needed to polish it, do the double checks, make sure everybody could see it, bless it and do it were the same teams that within another hour had to go on console and do the tanking. And then I needed them to be on console for launch and to stay sharp.
"When we looked at that and we started to judge our readiness, we basically said you know what? The better part of valor here is to take a day, let us go polish that off, make sure we really understand what's going on."
Engineers believe the valve is operating normally and that for some reason, the position indicator, which measures the movement of a pneumgatically-driven gear that pushes the valve open and closed with pressurized helium, failed to operate normally during tanking Tuesday.
It may work normally during fueling Friday afternoon, or it may malfunction again. If engineers do not get a closed indication, Moses said procedures will be in place to evaluate secondary cues to confirm the valve is, in fact, closed. Secondary methods include the timing of the valve gear movement and levels of helium in the aft compartment from the pneumatic system.
"We want to make sure we're ready," Moses said. "If we're wrong, we want to make sure we really do understand that there's not some other mechanism that we're not quite smart enough to think of yet that might fake us out on some of these other signatures."
One concern is making sure the valve does not drive partially closed, allowing hydrogen to leak through.
"One of the consequences here is that if that valve doesn't get sealed up, after liftoff, or right at startup I should say, when we close the outboard fill and drain valve and start draining that system, if there's leakage, liquid hydrogen will bleed back through into this little cavity and then turn into a gas and bleed itself back into the main engines," Moses said. "Ingesting gas into that main engine hydrogen manifold is probably not a good thing."
As a result, the MMT will review the analysis to date "to see we really do have some confidence, even if we do have a tiny bit of leakage past this valve, it would be what we consider 'spec' leakage," Moses said.
The extra day will help engineers "make sure we had a true bullet-proof story and we really knew what the teams on console would execute when we see, or don't see, this closed indicator."
02:40 PM, 8/26/09: Engineers prepare for valve tests; initial analysis shows 'fly as is' only option that fits in current launch window (UPDATED at 9:25 PM with successful valve/sensor tests)
An 8-inch hydrogen valve and a suspect position sensor in the shuttle Discovery's engine compartment that appeared to malfunction during fueling Tuesday, forcing NASA to scrub an early Wednesday launch, performed normally during five open-close cycles Wednesday evening, officials said.
The tests, carried out after Discovery's external tank was drained of rocket fuel, gave engineers added confidence the valve is not broken or on the verge of failure. But it does not yet explain why a position sensor failed to indicate the valve had closed properly during fueling Tuesday.
Additional fuel line pressure decay tests were being carried out late Wednesday, but barring an unexpected result, the launch team planned to resume Discovery's countdown at 8:57 a.m. EDT Thursday for a possible launch attempt at 12:22:09 a.m. Friday.
But that assumes NASA's Mission Management Team, scheduled to meet at 1 p.m. Thursday, finds no fault with the test data and approves a formal waiver to launch Discovery as is. Agreement on a waiver presumably would be based on a detailed engineering review and confirmation the valve's position could be indirectly verified during the final stages of the countdown.
Assuming the MMT opts to proceed, engineers will begin refueling Discovery at 2:57 p.m. Thursday. The astronauts - commander Rick Sturckow, pilot Kevin Ford, Jose Hernandez, John "Danny" Olivas, Patrick Forrester, European Space Agency astronaut Christer Fuglesang and space station flight engineer Nicole Stott - would begin strapping in around 9:02 p.m.
During fueling Tuesday for a planned 1:10 a.m. Wednesday launch, readings from Discovery's inboard liquid hydrogen fill-and-drain valve indicated it failed to fully close on command when the shuttle's external tank was nearing a full load of propellant.
Engineers quickly focused on the position sensor, part of a valve actuator system, as a possible culprit and not the valve itself. But to find out, they had to wait for Discovery's tank to be fully drained and "inerted" late Wednesday afternoon.
The valve cycle tests, using both the position sensor and indirect methods to confirm the state of the valve, began at 6:28 p.m. and concluded after five runs at 6:59 p.m. The sensor indicated normal valve operation, as did indirect helium pressurization readings.
"In all five tests, the valve opened and closed as designed," said NASA spokesman Allard Beutel.
But the tests Wednesday were carried out under ambient conditions and it's possible the sensor was affected by supercold cryogenic conditions during fueling Tuesday. But as of this writing, the anomaly remains unexplained.
A scheduling assessment early Wednesday showed the fly-as-is option was the only approach currently under discussion that gives NASA a chance of getting Discovery off the ground before its current launch window closes Sunday.
Window considerations aside, replacement of the position sensor and actuator would delay launch to Sept. 3. Replacement of the valve would push launch to around Sept. 5, according to an initial schedule outlining all three options.
But Discovery's current launch window only runs through Sunday, Aug. 30. The Air Force Eastern Range, which provides tracking and telemetry support, is unavailable from Aug. 31 through the next several days because of an unidentified, presumably military operation.
Assuming nothing changes on that front, Discovery's crew then would have to wait on upcoming Japanese and Russian space station missions. As it now stands, the next shuttle launch opportunity after Aug. 30 is around Oct. 17.
The shuttle is equipped with four propellant fill-and-drain valves: inboard and outboard liquid hydrogen valves and two corresponding liquid oxygen valves. When the shuttle is loaded with fuel before launch, the liquid hydrogen and oxygen propellants are routed through launch pad tail service masts on each side of the shuttle, into the engine compartment, through the main engine plumbing and into the external tank.
The fill-and-drain valves are closed before launch and then opened in orbit, after external tank separation, to rid the engine lines of residual propellant that may be trapped in the system. The valves also must be opened to drain the external tank if a launch is delayed.
The inboard fill-and-drain valve must be operational and confirmed closed before launch.
NASA flight rules forbid cycling the valve for troubleshooting once fueling has started and the hardware is in a supercold cryogenic environment. The concern is that additional cycles could contribute to an existing problem, possibly causing galling and creating debris that could cause the valve to break or get stuck in the closed position. Testing the valve in ambient conditions puts less stress on the hardware.
11:45 PM, 8/25/09: Valve tests planned Wednesday for possible Friday launch attempt
Engineers plan to test a suspect hydrogen fill-and-drain valve aboard the shuttle Discovery late Wednesday to determine if the valve or a sensor system that measures its position is to blame for readings that forced NASA to call off the shuttle's countdown Tuesday, delaying launch from early Wednesday until Friday at the earliest.
If it turns out the position sensor was to blame - and if NASA managers can get comfortable launching Discovery without full instrumentation in a critical system - then a launch attempt Friday at 12:22 a.m. EDT might be feasible. But if engineers are forced to open the shuttle's engine compartment and replace any suspect components, launch could be delayed to around Oct. 17.
That's because Discovery's current launch window closes after Aug. 30 because of upcoming Japanese and Russian space station launches and because the Air Force Eastern Range, which provides tracking and telemetry support for all rockets launched from Florida, is booked for another operation in early September.
"Right now, I'm pretty confident in the schedule of attack that says we'll be really good to go on Friday if we come out with a good technical story that says we can fly without instrumentation," said MIke Moses, chairman of NASA's pre-launch Mission Management Team. "So we both have to first prove it is instrumentation and then prove we're OK to fly without instrumentation."
Engineers plan to begin testing the valve Wednesday afternoon or early evening, after Discovery's external tank is fully drained and free of any residual hydrogen gas.
"Basically around this time tomorrow, we'll be ready to have a technical discussion amongst the experts to say did that look like what we thought it did, do we think we're in good shape?" Moses said. "So heading into the midnight timeframe tomorrow, we'll probably know whether we are going to keep pressing forward (for a Friday launch) or we've learned we're not going to make it."
Because the space station launch window moves about 23 minutes earlier per day, Discovery has two launch opportunities Friday, the first at 12:22 a.m. and the second at 11:59 p.m.
The Mission Management Team plans to meet at noon Thursday to assess the progress of troubleshooting and to make a formal decision on whether to proceed with launch.
The problem developed around 5:52 p.m. Tuesday when the 8-inch-wide liquid hydrogen inboard fill-and-drain valve in Discovery's aft engine compartment was commanded to close during fueling, a routine step to slow the rate at which hydrogen flows into the shuttle's external tank. One position indicator showed the valve was no longer open, but the closed indicator never provided a reading and engineers were unsure of the valve's actual position.
The valve must be fully closed for launch. In the event of a delay, the valve also must be able to open back up to drain the giant external tank. In addition, the valve is opened in orbit to blow residual propellant out of the engine plumbing and into space.
NASA flight rules forbid cycling the valve for troubleshooting once fueling has started out of concern about galling, debris creation and the possibility a failing valve could get stuck or break in the closed position. Following the rules, NASA managers called off the countdown and ordered engineers to drain the external tank.
"As we got into tanking we ran across a failure signature today that really was one of those that's in our LCC (launch commit criteria) that doesn't give us a lot of options," said Moses. "Basically, it was an LH2 inboard fill-and-drain valve. these are the big valves in the 8-inch lines that feed the liquid hydrogen into the system. ... If we needed to drain the external tank, that's how we'd drain back out.
"In that 8-inch duct, there's a valve flap, and the valve is really kind of complicated. If you think about it, it's at cryogenic temperatures, it's liquid hydrogen in an 8-inch diameter pipe. It's a very big, complicated system. There's a gear drive mechanism that makes this valve lift off the little cover and rotate out of the way, it's kind of a visor type of valve. We have to have good indications that that valve is either open or closed, you want to make sure you know exactly where it is."
Based on two past failures, engineers found galling can create debris in the line that can cause a valve to jam.
"That's the thing we want to avoid," Moses said. "So the LCC's really set up to say you want to make sure that valve goes closed because it needs to be in a good closed position for launch, that's where you want it to be, but don't go cycling around because if it is broken or if it's about to break, you really need to make sure in a drain situation you can open that valve back up again. Otherwise, it's a very challenging job to drain the external tank. ... That's really the hazard we're trying to control."
He said engineers "really do think this is just telemetry. ... We have the pressure traces, we know it looks like the valve is going its full range of motion. But we have a much bigger database at ambient temperatures when we do valve checkouts on the ground pre-launch than we do here at cryo conditions. So we want to get back to that pre-launch state where we know it's an inert system, go run some valve cycle tests, compare those two sets of data and show we really do have just a position indicator problem.
"That's postulating," he said. "The teams are going to spend the next two days gathering the technical analysis that says if that's truly the situation, we're comfortable launching in that scenario. And then go gather the data to make sure it really matches with what we think.
"If we find that's not the case ... or the team just doesn't get comfortable that we really can tell truly that this valve is actually open or actually closed without this position indicator, then we would probably not be in position to launch 48 hours from now."
As if engineers didn't already have their hands full, telemetry during Tuesday's fueling indicated elevated levels of hydrogen gas in the tail service mast on the left side of the shuttle where the liquid hydrogen feedline attaches to the orbiter.
Launch Director Pete Nickolenko said engineers planned to take advantage of the launch delay to troubleshoot that issue as well.
6:10 PM, 8/25/09: LAUNCH SCRUBBED by apparently broken hydrogen valve in shuttle engine compartment
Trouble with a critical hydrogen fill-and-drain valve in the shuttle Discovery's aft engine compartment forced NASA managers to call off an attempt to launch the orbiter early Wednesday on a space station resupply mission. It was the second delay in a row for Discovery following a weather scrub earlier Tuesday.
"We have scrubbed for the evening, officially at 5:52 p.m. Eastern," said launch commentator Allard Beutel. "The last half an hour or so, a problem cropped up with a fill-and-drain valve in the bottom part of the shuttle, the aft part of the shuttle, related to the liquid hydrogen. This particular valve ... gave indications it did not close when it was commanded to."
It was not immediately clear what might be needed to replace the valve or restore it to normal operation.
But NASA only has until Aug. 30 to get Discovery off the ground or the flight will be delayed to mid October because of upcoming Japanese and Russian space station missions and a conflict with the Air Force Eastern Range, which provides tracking and telemetry support for all rockets launched from Florida.
With a 70 percent chance of good weather expected, engineers began fueling Discovery at 3:45 p.m., setting up a launch attempt at 1:10:22 a.m. Wednesday. But just before 6 p.m., engineers stopped loading liquid hydrogen when an inboard fill-and-drain valve appeared to malfunction.
"You have to have it closed for flight," said Beutel. "You don't want it to get stuck in the position where it's closed because you cannot drain the tank that way (after a delay). The Launch Director Pete Nickolenko has given the team's the direction to stop the fill of liquid hydrogen, so they have, and there are discussions going on now with the team and space shuttle launch management."
He said engineers were no sure of the exact state of the inboard hydrogen fill-and-drain valve.
"This is not one of those valves that allows (cycling) because you don't want to have it in a position of broken/closed," he said. "So with that, the liquid hydrogen filling of the external tank has stopped."
Additional details will be posted as they become available.
3:55 PM, 8/25/09: Shuttle fueling begins
Working by remote control, engineers began refueling the shuttle Discovery today for launch early Wednesday on a space station resupply mission. The three-hour fueling procedure began on time at 3:45 p.m. EDT with the initial flow of supercold liquid oxygen and hydrogen rocket fuel from storage tanks to the shuttle atop pad 39A. The process should be complete by around 6:45 p.m.
1:45 PM, 8/25/09: Forecast 70 percent 'go' for Wednesday launch
Engineers are gearing up to refuel the shuttle Discovery later today for a delayed launch on a space station resupply mission. There are no technical problems of any significance at pad 39A and forecasters are predicting a 70 percent chance of good weather at launch time Wednesday morning.
Fueling is scheduled to begin at 3:45 p.m. EDT. Discovery's astronauts plan to strap in starting around 9:50 p.m. to await liftoff at 1:10:22 a.m. Wednesday.
A launch attempt earlier today was called off when thunderstorms and electrically charged anvil clouds moved into the area, violating NASA's flight rules for both launch and landing. The forecast for Wednesday's attempt calls for a 30 percent chance of weather that could delay fueling and launch.
"An upper level trough is located in the Eastern US and a surface boundary is located over Central Florida," according to the 45th Weather Squadron at Patrick Air Force Base. "The boundary will migrate slowly northward as the upper level trough gradually weakens. There is still a possibility thunderstorms may affect the area near tanking time as the boundary moves north.
"By launch time, the boundary will be northwest of KSC. There is a chance of showers near the area at launch time. Our primary concerns for launch are cumulus clouds within 10 (nautical miles) of the launch pad and showers within 20NM of the Shuttle Landing Facility (SLF). Easterly flow will prevail the following two days increasing the chance for showers in the area near launch time. Also, a tropical wave near Puerto Rico may develop and impact seas for SRB recovery if the launch delays beyond Wednesday morning."
The outlook for Thursday calls for a 60 percent chance of acceptable weather, dropping to 40 percent for Discovery's first launch opportunity Friday. Because the space station launch windows moves about 25 minutes earlier per day, Discovery has two launch opportunities Friday, the first at 12:22 a.m. and the second at 11:59 p.m.
The Spaceflight Meteorology Group at the Johnson Space Center in Houston is responsible for forecasting the weather as it relates to an emergency return-to-launch-site abort and landing back at the Kennedy Space Center. The SMG is predicting just a few clouds at 3,000 feet, scattered clouds at 16,000 feet and a broken deck at 25,000 feet with winds out of the east at 7 knots, gusting to 11. SMG predicts a slight chance of thunderstorms within 20 nautical miles of the shuttle's runway. Possible flight rule violations include electrically charged anvil clouds in the vicinity, lightning and precipitation.
A revised shuttle countdown, ascent abort timeline, trajectory data and revision A of the NASA television schedule are posted on the CBS News STS-128 Quick-Look page. A flight plan revision is in work and will be posted later today, along with an updated version of SpaceCalc that reflects Discovery's 24-hour launch delay.
1:50 AM, 8/25/09: LAUNCH SCRUBBED by bad weather; countdown reset for Wednesday launch try
Florida's hard-to-predict weather threw the shuttle Discovery's crew a curve ball early Tuesday, worsening when forecasters predicted improvement, generating unexpected lightning and offshore storms. While conditions improved as the morning wore on, the launch team ran out of time and NASA managers were forced to order a 24-hour delay.
"Well looks like everything else was cooperating except for our local area weather," Launch Director Pete Nickolenko said to Mike Moses, chairman of NASA's Mission Management Team, during a final hold in the countdown.
"Yep, if we had 30 more minutes to go I think we'd have a real good shot today," Moses said. "But it's obviously not the right thing to do today. So we can knock it off."
"Yes sir, will do," Nickolenko said at 1:25 a.m. He then called Discovery commander Frederick "Rick" Sturckow, saying "well CJ, the vehicle and the operations were cooperating but the local weather unfortunately did not. So we'll have to scrub for the day, but hope to try again tomorrow."
"We copy that, sir," Sturckow replied. "When the weather is ready to cooperate, we'll be ready to go."
Launch was originally set for 1:36:04 a.m. EDT Tuesday and other than the weather, there were no problems of any significance.
Forecasters predicted an 80 percent chance of good weather at launch time, but the air was unstable, storms did not dissipate as expected and the forecast was downgraded to 60 percent no-go after the crew strapped in for launch.
Radar showing storms near Discovery's launch pad.
(Photo: NASA TV)
Finally, with rain showers and lightning strikes near the pad, Nickolenko called off the countdown.
Sturckow, pilot Kevin Ford, flight engineer Jose Hernandez, Patrick Forrester, John "Danny" Olivas, European Space Agency astronaut Christer Fuglesang and space station flight engineer Nicole Stott planned to climb out of the orbiter and return to crew quarters to await another try early Wednesday.
Assuming no problems develop, NASA will reset the countdown for a launch attempt at 1:10:22 a.m. Wednesday. The most recent forecast called for a 70 percent chance of acceptable conditions.
NASA must get Discovery off the pad by Aug. 30, or the flight will be delayed to mid October because of upcoming Japanese and Russian space station launches and a conflict with the Air Force Eastern Range, which provides tracking and telemetry for all rockets launched from Florida.
If the weather or a technical problem prevents a launch Wednesday, the shuttle team likely will stand down for 24 hours and then make two more back-to-back attempts Friday and Saturday.
The primary goals of the 13-day mission are to deliver more than 7.5 tons of equipment and supplies to the International Space Station and to ferry Stott to the lab complex to replace outgoing flight engineer Timothy Kopra.
12:05 AM, 8/25/09: Weather deteriorates; forecast moves from 80 percent 'go' to 60 percent no-go
Thunderstorms near the Kennedy Space Center have not dissipated as forecasters predicted, forcing them to revise the outlook for the shuttle Discovery's launch early Tuesday from 80 percent "go" to 60 percent no-go.
With an hour and a half to go before launch, NASA managers were monitoring several weather violations, including lightning near the launch pad. Discovery's seven-member crew is strapped in and there are no technical problems of any significance that would delay launch, targeted for 1:36:04 a.m. EDT.
But the weather is an open question and forecasters say conditions are more unstable than expected.
10:30 PM, 8/24/09: Astronauts strap in for launch
The shuttle Discovery's crew donned pressure suits, headed to launch pad 39A and began strapping in late Monday for blastoff at 1:36:04 a.m. EDT Tuesday on a 13-day space station resupply mission.
The astronauts departed crew quarters at the Operations and Checkout Building in the Kennedy Space Center industrial area at 9:44 p.m., reaching the launch pad about 20 minutes later.
Commander Rick Sturckow straps in aboard Discovery.
(Photo: NASA TV)
Commander Frederick "Rick" Sturckow, pilot Kevin Ford, flight engineer Jose Hernandez and Patrick Forrester will make the ride to space on Discovery's upper flight deck. John "Danny" Olivas, European Space Agency astronaut Christer Fuglesang and space station flight engineer Nicole Stott will be strapped in on the shuttle's lower deck.
There are no technical problems of any significance and the shuttle's systems appear to be operating normally. Engineers are assessing a small ice buildup on cables and propellant lines leading from the launch pad to the shuttle's aft engine compartment, but similar buildups have been seen in past countdowns.
Forecasters remain optimistic about the weather. Afternoon thunderstorms near the space center dissipated after sunset and while some clouds remained in the area, engineers were hopeful the clearing trend would persist, allowing an on-time liftoff.
8:00 PM, 8/24/09: Shuttle fueled for launch
The shuttle Discovery was loaded with a half-million gallons of liquid oxygen and hydrogen rocket fuel late today in preparation for a launch attempt at 1:36:04 a.m. EDT Tuesday.
There were no technical problems of any significance during the three-hour fueling procedure and a hydrogen vent line that leaked in June, delaying the previous shuttle flight, is working normally this evening.
Shuttle Discovery, fueled for launch. (Photo: NASA TV)
The only question mark is the weather, with storm cells and threatening clouds over the spaceport in the late afternoon and early evening. But forecasters are optimistic the clouds will dissipate as the evening wears on.
4:15 PM, 8/24/09: Shuttle fueling begins
Working by remote control, engineers began pumping a half-million gallons of liquid oxygen and hydrogen rocket fuel into the shuttle Discovery's external tank today starting at 4:11 p.m. EDT, setting the stage for launch on a space station resupply mission at 1:36:04 a.m. Tuesday.
Engineers in Firing Room 4 monitor the shuttle Discovery's
fueling for launch. (Photo: NASA TV)
There are no technical problems of any significance at pad 39A and forecasters said the sea breeze was keeping inland showers well away. With only a 20 percent chance of lightning in the area during the first hour of fueling, NASA managers gave engineers permission to proceed with tanking. The forecast for launch time Tuesday is 80 percent "go."
The three-hour fueling procedure should be complete just after 7 p.m. Discovery's crew - commander Frederick Sturckow, pilot Kevin Ford, flight engineer Jose Hernandez, Patrick Forrester, John "Danny" Olivas, European Space Agency astronaut Christer Fuglesang and space station flight engineer Nicole Stott - plans to begin strapping in around 10:16 p.m.
6:15 PM, 8/23/09: NASA managers, in final review, clear Discovery for launch Tuesday
NASA managers reviewed a few final technical issues Sunday and cleared Discovery for launch early Tuesday on a 13-day three-spacewalk mission to deliver 7.5 tons of equipment and supplies to the International Space Station.
The only issue going into the final hours of the countdown is the weather, with a 40 percent chance of afternoon thunderstorms Monday that could delay fueling. Assuming the weather cooperates and fueling gets under way within a few hours of the 4:11 p.m. EDT start time, the forecast calls for an 80 percent chance of good weather for launch Tuesday at 1:36:05 a.m.
"Overall the weather is looking good for launch, we've just got to get there," said shuttle weather officer Kathy Winters. "And so the tanking weather is what we'll be watching very closely. But by the time we get to launch, there is just a 20 percent chance of KSC weather prohibiting launch."
The forecast for a 24-hour delay calls for a 20 percent chance of afternoon thunderstorms that would delay fueling Tuesday and a 30 percent chance of bad weather at launch time early Wednesday. The forecast is the same for a launch Thursday, but in that case forecasters only expect a 10 percent chance of bad weather for tanking.
Because of a conflict with the Air Force Eastern Range, which provides telemetry and tracking support for all rockets launched from Florida, Discovery must get off by Aug. 30 or the flight likely will slip to mid-October, after upcoming Japanese and Russian space station missions.
NASA's Mission Management Team met Sunday for a traditional launch-minus-two-day readiness review to close out open paperwork and discuss any unresolved technical issues.
The major item on the agenda Sunday was an analysis of flight rationale after the recent failure of a power control assembly aboard Discovery and two similar failures in an avionics test rig at the Johnson Space Center in Houston.
The shuttle is equipped with power switching assemblies tied into each of the ship's three electrical buses to route electrical power to forward rocket thrusters, payload bay hardware and the shuttle's aft reaction control system thrusters.
Forward power control assembly No. 3 failed aboard Discovery during launch pad checkout, forcing engineers to replace the unit with a spare. That failure, plus two similar malfunctions in the Shuttle Avionics and Integration Laboratory at Johnson, prompted an in-depth analysis.
Disassembling the units, engineers discovered presumed metal fatigue problems with a solenoid relay system. It is not yet known whether the observed fatigue was caused by poor workmanship, the stress of normal operations since the boxes were built or both.
The boxes cannot be opened and inspected without voiding their flight certification and triggering a lengthy delay. As a result, mission managers do not know the condition of the suspect components installed aboard Discovery, all currently powered on and operating normally. An assessment of the potential impacts of an in-orbit failure dominated Sunday's engineering review.
Mike Moses, chairman of NASA's pre-launch Mission Management Team, said a failure does not change the state of the device. If the suspect controller component failed when it was powered on, the downstream circuits would remain powered. If it was off and then failed when commands were sent to turn it on, the circuit would remain unpowered.
Moses said a thorough review of shuttle systems identified just one major area of concern: how a failure might impact the crew's ability to operate the shuttle's forward and aft maneuvering jets.
Power to the "reaction jet drivers," or RJDs, normally is turned off after the shuttle reaches orbit and then turned on only when needed to conserve propellant and to prevent jarring thruster firings during crew sleep or when the shuttle is docked to the space station.
To protect against a power control assembly failure during Discovery's flight, the RJDs will remain on through the shuttle's docking with the International Space Station and then turned off. If a failure occurs at that point, the jets would remain powered and flight controllers would disable them as required using the shuttle's flight software.
If the device worked normally to turn off the RJDs after docking and then failed during power-up just before undocking, Moses said the crew would be able to proceed because the aft thrusters have an alternate source of power and the shuttle's forward thrusters are not needed for undocking and re-entry. It would take multiple failures to cause a real problem and the odds of that were considered acceptably low.
"Everybody was fine with our flight rationale," Moses said of the decision to proceed.
One other technical issue was discussed Sunday involving analysis and inspections of a flow control valve used aboard the shuttle Endeavour last month.
The flow control valves are used to maintain the proper pressure in the shuttle's external tank during the climb to space. Recent problems with cracks prompted NASA to implement strict new inspection guidelines to minimize the chances for development of cracks that might release debris in the system.
As it turns out, the guidelines were not strict enough. Engineers discovered a valve flown aboard Endeavour last month developed a crack even though it passed its pre-launch "eddy current" inspection. New acceptance guidelines have been implemented and the threshold for rejecting a valve has been tightened.
Moses said all three of the flow control valves aboard Discovery met the new guidelines.
2:44 PM, 8/22/09: STS-128 Mission Preview
KENNEDY SPACE CENTER, Fla. -- After last-minute debate over external tank insulation, the shuttle Discovery is poised for launch early Tuesday on a three-spacewalk mission to deliver more than seven tons of supplies, experiment hardware and life-support gear to the International Space Station.
Along with replacing a 1,800-pound ammonia coolant tank in the station's main power truss during their first two spacewalks, the astronauts will deliver two sophisticated science racks, one devoted to fluid physics and the other to materials science, an experiment sample freezer, a new air revitalization rack, a crew sleep station and a treadmill named after comedian Stephen Colbert.
The "Combined Operational Load Bearing External Resistance Treadmill," or COLBERT, received its name after the comedian launched a successful tongue-in-cheek write-in campaign to name a final station module in his honor. NASA managers declined, naming the new module Tranquility instead, but renamed the treadmill after Colbert.
Astronaut Nicole Stott, a former shuttle engineer at the Kennedy Space Center who joined the astronaut corps in 2000, is hitching a ride to the space station aboard Discovery to replace flight engineer Timothy Kopra, launched to the lab complex in July and returning to Earth in Stott's place.
Remaining behind when Discovery departs, Stott will join Expedition 20 commander Gennady Padalka, NASA flight engineer Michael Barratt, cosmonaut Roman Romanenko, Canadian Robert Thirsk and European Space Agency astronaut Frank De Winne as a member of the station's full-time crew.
Discovery's flight is the last shuttle mission that will rotate space station crew members. While Stott will ride a shuttle home in November, future station crew members will travel up and down aboard Russian Soyuz capsules. NASA is paying the Russian space agency roughly $50 million per seat while the U.S. agency closes out shuttle operations and works to develop a replacement spacecraft not expected to fly until 2015 at the earliest.
Only six shuttle flights are planned after Discovery's mission, all of them devoted to finishing the space station and loading it with supplies, spare parts and other equipment to protect against failures after the shuttle fleet is retired.
Launching enough supplies and equipment to support a full-time crew of six is a major challenge and one that Stott will face right away. She will be responsible for operating the station's robot arm to capture and attach an unmanned Japanese supply ship being prepared for its maiden launch Sept. 10. If all goes well, Stott will pluck the HTV craft out of orbit Sept. 17 and dock it to the Harmony module's Earth-facing port.
Discovery's flight is equally critical to maintaining a permanent presence in space. Along with delivering science hardware and life support equipment, the shuttle crew also will bring up 1,600 pounds of food and other supplies, including carbon dioxide-absorbing lithium hydroxide canisters, used to supplement the station's U.S. and Russian CO2 scrubbers.
"We're bringing up seven racks that will be transferred to the space station," said European Space Agency astronaut Christer Fuglesang, making his second shuttle flight. "Three of them are really to keep the station's six crew members well and alive. There's a crew quarters, a treadmill - you have to exercise twice a day if you stay in space up to six months - and then there's a system to keep the air clean. Then we're bringing up three racks dedicated to science. And of course, there's a lot of food and other things."
Fuglesang, Stott and their shuttle crewmates - commander Rick Sturckow, pilot Kevin Ford, Jose Hernandez, John "Danny" Olivas and Patrick Forrester - are scheduled for liftoff at 1:36:05 a.m. on Aug. 25. Ford, Hernandez and Stott are space rookies making their first flight. Sturckow is a three-flight veteran, Forrester has two previous missions to his credit while Olivas and Fuglesang each have one.
Hernandez, a father of five, became an astronaut after a childhood of migrant farm work and support from hard-working parents who believed in the value of education.
"I come from a traditional migrant farm working family," he told CBS News. "Every year, my dad in central Mexico used to pile up the kids and my mom in the car and we'd take a two-day trip up to southern California, this is in the March timeframe, and then we would go to about three or four different places all the way up to northern California, Stockton was our last point where we'd spend the bulk of our time and we'd work on whatever crops were in season.
"We'd work on picking the cucumbers, cherries, tomatoes, spring tomatoes for market, peaches, grapes, hard work. The difference between my parents and the typical migrant farm working families is they gave importance, in spite of their third grade education, to give more importance to education. So Monday through Friday we would be in school, unlike some other kids who would be working seven days a week. Saturday and Sunday, we were always working out in the fields. We hated summer vacation because we knew what that meant. That meant seven days a week in the fields!"
"Then November would roll around, he would ask us to get two or three months of homework and we would head back to Mexico and the process repeated itself," Hernandez said. "It wasn't until I was in the second grade - I'm the youngest in the family - I told my second grade teacher I needed my homework, she rolled her eyes and said 'tell your parents I'm going to pay them a visit.'
"So she came and in her broken Spanish and my parent's broken English, basically told my parents 'look, I've had all four of your kids, they're all bright, they have a good future in school. Stay in one place so they have a good chance of getting a good education.' And my dad, again, in spite of a third grade education, gave that a lot of importance coming from a teacher. So we started making Stockton our home and the rest is history."
Hernandez will serve as flight engineer during Discovery's launch and landing, operate the shuttle's robot arm for heat shield inspections the day after launch and at the end of the mission before re-entry, set up the shuttle's laptop computer network and oversee critical instrument readings during rendezvous and docking with the space station. He also will help spacewalkers Olivas, Fuglesang and Stott suit up for three planned excursions.
Hernandez' wife, children, siblings and parents planned to attend Discovery's launch at the Kennedy Space Center.
"They were happy if we finished high school" Hernandez said of his parents, "because that means we weren't going to work in the fields. They were ecstatic all four of us got a college education. Now I tell everybody that the minute I blast off into space, they're going to be in a higher orbit than I am, as happy as they're going to be."
Assuming an on-time liftoff, Sturckow will guide Discovery to a link up with the space station around 10:30 p.m. on Aug. 26. As with all station-shuttle dockings, Sturckow will briefly stop the approach 600 feet directly below the lab complex, piloting the shuttle through a 360-degree back flip maneuver while Padalka and Barratt, using cameras with 400-mm and 800-mm telephoto lenses, document the condition of the ship's heat shield.
Those photos, along with ascent imagery and laser-scan data collected by Hernandez and Forrester the day after launch, will be examined by engineers at the Johnson Space Center in Houston to make sure Discovery's critical reinforced carbon carbon nose cap, wing leading edge panels and belly tiles are in good condition for re-entry.
A potential source of debris for ascent impact damage is foam insulation from the shuttle's external tank. A major question mark going into Discovery's launch campaign was the integrity of that foam after an unusual amount of insulation fell away from the shuttle Endeavour's tank during launch July 15.
Most of the lost foam fell from ET-131's central intertank region, along with a small piece from a so-called ice-frost ramp that helps secure a pressurization line to the upper liquid oxygen section of the tank.
Some of the debris struck Endeavour's heat shield, but the impacts occurred after the shuttle was out of the denser lower atmosphere, which can result in higher impact velocities, and damage was minimal. Impact modeling is not an exact science, however, and engineers were concerned about possible problems with the adhesion of the foam to the tank's underlying structure.
As a result, Discovery's tank was subjected to nearly 200 plug-pull tests in which small cores cut in the intertank foam were pulled on with a known force to make sure the insulation was held in place with the required strength. In all cases, the adhesion was at or above specification.
The ice-frost ramp foam loss was more troublesome because Endeavour's flight was the second in a row in which insulation fell away from a specific IFR. Engineers believe the insulation popped off when air trapped in voids in the foam expanded due to atmospheric heating during ascent. But with two foam shedding incidents in a row, engineers worried a generic processing problem might be resulting in bigger voids and more shedding than usual.
The IFR in question on Discovery's tank was examined with a non-destructive terahertz scanner and found to be free of any major voids. But three other IFRs, none of them with a history of foam shedding, were not inspected. Some elements of the shuttle engineering community later recommended rolling Discovery back to the Vehicle Assembly Building for additional inspections, work that would have delayed launch to mid October.
Instead, NASA managers ordered additional terahertz scans of the IFRs on the next tank in the launch sequence to make sure there was not a generic problem. No major problems were found and senior managers at an executive-level flight readiness review cleared Discovery for launch as is.
"On Columbia, we had a 2.2-pound piece of foam come off and damage the wing," said shuttle Program Manager John Shannon, referring to the shuttle Columbia's destruction in 2003. "The loss we had on the last flight that generated all of this discussion over the last two weeks was 0.044 pounds, which is one-fiftieth the size of the Columbia foam.
"That's how close we're looking, that's how sensitive we are. It generated four days of flight readiness review discussion, and a whole lot of work and additional testing. And that's exactly what we want the team to do, to look at it that closely. I feel extremely good about the results of the meeting. I think we have done absolute due diligence on the foam piece of it."
While Discovery's tank will separate from the shuttle in orbital darkness following the climb to space, a robotic camera mounted in the belly of the spaceplane will use a flash to capture photos giving engineers a chance to assess the condition of the tank's insulation.
Close-up photos of the shuttle shot by the station astronauts during Discovery's pitch-around maneuver on docking day also will be transmitted to the Johnson Space Center for detailed analysis. If any problems are seen, the astronauts will carry out a "focused" inspection later in the mission to collect additional data.
Following the rotational pitch maneuver, Sturckow plans to guide Discovery in an arc up to a point about 450 feet directly in front of the space station, with the shuttle's nose pointed toward space, it's tail to Earth and its open payload bay facing a docking port on the front end of the Harmony module. From there, Sturckow will manually guide the 270,000 pound shuttle to a docking with the 700,000-pound space station as both spacecraft streak through space at five miles per second.
With Discovery's arrival, the space station will once again be home to an international crew of 13, a record set during Endeavour's July mission, putting an increased strain on the lab's life support systems. During the July flight, the station's U.S. carbon dioxide removal system broke down, but the astronauts were able to repair it a few days after the shuttle's departure.
More recently, a U.S. oxygen generator had to be shut down to resolve an internal pressurization problem. While it wasn't required for DIscovery's flight, the station astronauts completed repairs Friday, easing a potential downstream headache.
The first item on the agenda after Discovery's docking will be the transfer of Stott's custom-fitted Soyuz seat liner, which will enable her to use one of the station's Russian life boats. From that point on, Stott will be considered a member of the station crew while Kopra will join Sturckow and company.The day after docking, Ford and Barratt, operating the space station's robot arm, will lock onto the Leonardo multi-purpose logistics module, or MPLM, mounted in the back of Discovery's cargo bay. Loaded with 7.5 tons of equipment and supplies, Leonardo will be attached to Harmony's Earth-facing port.
"As we transition to six-person crew, there's a big step up in terms of consumables," said Kirk Shireman, deputy manager of the space station program at the Johnson Space Center. "And this flight will really get us in a robust configuration for keeping six-person crew and to fully utilize the ISS.
"We're launching about 1,590 pounds of crew supplies, that's food and other things to keep the crew alive and happy, we're launching 6,190 pounds of what I call vehicle hardware, and this is things in preparation for assembly, spares, those kinds of things. And we're launching over 6,050 pounds of utilization hardware. That's several racks and payloads themselves. So it's a big flight to fully utilize the International Space Station."
Fuglesang is the "load master" responsible for overseeing the logistics transfers to and from the MPLM, assisted by Sturckow and other crew members. Along with the new science racks, major items of interest include a new crew sleep station and the COLBERT treadmill.
The space station currently is equipped with four small crew cabins, two in the Russian Zvezda command module, used by Padalka and Romanenko, and two U.S.-built cabins on the port and starboard side of the Harmony module, used by Barratt and Kopra. De Winne uses a temporary sleep station, or TeSS, in the U.S. Destiny laboratory module while Thirsk bunks in a similar makeshift cabin in the Japanese Kibo module.
Stott will take over Kopra's cabin in Harmony while Thirsk will enjoy the new NASA crew cabin, which will be temporarily mounted in Kibo and eventually moved to Harmony. A fourth U.S. sleep station will be launched next year and installed in Harmony as well.
The U.S. sleep stations have a volume of 54 cubic feet, about the same as a large refrigerator. They are sound-proofed and feature their own lighting, air ducts, computer ports, communications gear and alarm systems. Arranged in a ring around Harmony, plastic sheathing at the back of each cabin also provides radiation shielding.
"They are very cool," Stott said. "I think it's going to be nice. You show some people the space that's available and they're like, oh my gosh, how could you possibly do that? You think about it, though, it's like this volume that's available to you, it's the whole volume, you're not relying on sticking to a wall somewhere or anything like that. Just like the station in general, you have this whole volume to use."
The new sleep station delivered by Discovery's crew eventually will be mounted in the new Tranquility module, along with the COLBERT treadmill, the second built for the space station. A half-dozen other exercise devices are available as well to facilitate daily exercise by all six crew members to help counteract the long-term effects of weightlessness.
Because of the connection with Stephen Colbert, the new treadmill, also known as T2, has generated more publicity than usual.
"We're always thankful for another outlet for positive exposure of the station, the hardware and the good things that are going on up there," Stott said. "We will be spending, I think, roughly 30 to 40 hours putting this treadmill together, between Mike Barratt and I.
"I think the highlight will be the first time we actually get to run on it. That will be a really good day, because we have the opportunity then to continue to sustain six people on station and have healthy crew members up there. So I think it's a very positive thing."
After the MPLM is attached to the station, Stott and Olivas will spend the night in the space station's Quest airlock module to prepare for the mission's first spacewalk the next day. The primary goals of the excursion are to remove a depleted ammonia tank assembly, or ATA, and attach it to the space station's robot arm for temporary storage. The astronauts also will retrieve two experiment packages mounted on the European Space Agency's Columbus lab module.
Tipping the scales at some 1,800 pounds on Earth, the ATA is the most massive space station component ever handled by spacewalking astronauts.
"In zero G (gravity), we sort of think of everything as being weightless and being easy to move around," said Zeb Scoville, the lead spacewalk officer at JSC. "The thing to remember is that although those things have no weight, they still have mass. ... They're going to have to try to manipulate that mass so it doesn't try to pull them out of their foot restraints. Keeping control of this is certainly a challenge, again because of the mass, the inertia and the fact that it sometimes wants to resist being turned or re-oriented."
Another issue is potential ammonia contamination.
"Several days before the first spacewalk, the fluid lines that run internal to the ammonia tank and also run from that ammonia tank along the truss structure into the fluid system, a section of that line will be vented so there will only be residual bits of ammonia inside, there won't be the large pressurization volume of ammonia in those lines when they are demated," Scoville said. "So the amount of ammonia that could potentially leak is limited in that regard.
"If a crew member does get sprayed, we'll have time outside, exposed to the sun, the warm external environment, to bake off any ammonia ice that may be stuck on the suit. Beyond that bake-out scenario, we have some testing hardware once the crew ingresses the airlock. They can do a test at 5 psi that will detect any ammonia that may be off gassing from the suit. So, we'll be able to verify the crew is in a clean configuration before they come inside."
Stott and Olivas will disconnect the old ammonia tank from the port-1 truss segment and pull it out. Holding it in their gloved hands, the astronauts will orient the tank so Ford, operating the station's robot arm, can lock on. The tank will remain on the end of the station arm until after the new ammonia tank is installed during the crew's second spacewalk. After that, the old tank will be mounted on a cargo carrier in the shuttle's payload bay for return to Earth, refurbishment and relaunch next year.
"Nicole and Danny have a lot of work to do to disconnect the plumbing and electrical and all that stuff and make sure the (old) tank's vented and everything," Ford said. "It's going to be interesting, they're going to actually hold that tank out there and position it in their hands while I grapple it with the big arm. Then I'll take that away from them and I'll hold onto that until almost the end of EVA-2."
With the old ammonia tank safely locked to the station's robot arm, Stott and Olivas will move to the outboard end of the Columbia module and retrieve two experiment packages, mounting them in Discovery's cargo bay for return to Earth.
The next day, the shuttle astronauts will focus on logistics transfers from the MPLM, moving the fluid physics, materials science and freezer racks to the space station. Olivas and Fuglesang will end the day retiring to the Quest airlock to gear up for spacewalk No. 2 on Aug. 30.
The goal of the second EVA is to finish the ammonia tank swap out. With the old ATA still attached to the station's robot arm, Olivas and Fuglesang will work in the back of the shuttle's cargo bay to unbolt the new tank from an external storage platform.
With his feet anchored to a foot restraint on the end of the arm, Fuglesang will hand carry the fully charged ATA from the shuttle's cargo bay up to the P1 truss segment.
"It has motivated me a little extra to go to the gym quite often," he joked before launch.
He and Olivas then will slide the new tank into place and make the necessary structural and electrical connections, along with hooking up a nitrogen pressurization line and an ammonia coolant line.
With the new tank installed and connected, the robot arm will release the old tank and Olivas will hold it in place for a handoff to Fuglesang. The Swedish astronaut, riding the robot arm, will carry the old tank back to Discovery's cargo bay where it will be bolted down on the same carrier used by the new tank for the ride to orbit.
The next day, the shuttle crew will enjoy a half-day off amid work to continue logistics transfers from the MPLM The day after that, Olivas and Fuglesang will stage a third and final spacewalk to deploy an external cargo mounting mechanism, swap out a rate gyro assembly and make preparations for the attachment next year of the new Tranquility module.
Tranquility, also known as node 3, is the third multi-hatch connecting module built for the space station. It will be mounted on the central Unity module's left port directly across from the Quest airlock. The new Air Revitalization System rack and the COLBERT treadmill ultimately will be installed in Tranquility.
To pave the way for Tranquility's attachment, Olivas and Fuglesang plan to run two 60-foot-long electrical cables from the station's central power truss to the port side of the Unity module, unrolling the cables and tying them down as they go.
"These cables are about an inch-and-a-half to two inches in diameter and they're really stiff," Scoville said. "If you bend them, they'll hold that shape pretty well. And so we'll definitely be aware of any sort of memory, or stiffness, that these cables may have or if they want to retain the shape they initially had."
The spacewalkers will carry the cables from the Quest airlock rolled up in loops about two feet across.
"With each coil, we've taken one of these copper wire ties ... and we twist each loop with one of these wire ties," Scoville said. "As they pull off one loop, they can release that one wire tie, pull off maybe just five or so feet, secure that down to structure while they hold onto the rest of it. They can move down the truss structure a little bit, undo one twist tie, get the second loop off and start working on that.
"As controlled as that may sound, cables have always presented a challenge in the past just because they do have a lot of memory and sort of a mind of their own," he said. "We've done our best to try to control that."
Said Olivas: "Just think about when you're hanging up Christmas lights. The Christmas before you end up just kind of sticking them in the box and then when it's time for Christmas, you pull them out, you think to yourself, oh, what did I do?"
The cable coils "are big and they're bulky, but when we pull them out of the bag it seems like every time we pull them out it's just like pulling out one of those big strands of lights," he said. "You don't have a ladder you can use up in space, you're floating around there. So it is a bit of a challenge. But we've trained it, we've had an opportunity to work with the engineering community to make sure we understand all the aspects of that EVA. So we're well prepared for it."
With the third spacewalk behind them, the Discovery astronauts will enjoy another half-day off after spending the morning on final MPLM transfers. The next day - Sept. 3, assuming an on-time launch - the crew will close up the Leonardo module and Ford will use the station's robot arm to move it back to its mounting point in Discovery's cargo bay.
With Leonardo safely locked down for the trip home, the astronauts will hold a traditional farewell ceremony in the Harmony module before Sturckow, Ford, Hernandez, Olivas, Forrester, Fuglesang and Kopra float back into the shuttle and hatches between the two spacecraft are closed and leak tested.
Undocking is scheduled the following day, around 4:50 p.m. on Sept. 4. With Ford at the controls, Discovery will pull out in front of the station before initiating a 360-degree photo-documentation fly around at a distance of about 600 feet. A rocket firing at the end of the maneuver will cause the shuttle to slowly leave the area.
At that point, Hernandez and Forrester will carry out a final inspection of Discovery's nose cap and wing leading edge panels to look for signs of micrometeoroid or space debris impact damage that might have occurred since the inspection they carried out the day after launch.
Assuming no problems are found, the astronauts will test the shuttle's re-entry systems the next day and pack up for landing Sept. 6 back at the Kennedy Space Center.
"We're really happy to have this mission," Sturckow said in an interview. "It's great to fly on the shuttle, we've had a great flow together as a crew with our training. We're excited and looking forward to the mission."
11:40 AM, 8/22/09: Countdown on schedule; weather unchanged at 70 percent 'go'
The shuttle Discovery's countdown is proceeding smoothly through its initial hours with no technical problems of any significance, officials said Saturday. The weather remains unchanged, with forecasters calling for a 70 percent chance of acceptable conditions at launch time Tuesday.
"All of our vehicle systems are in good shape," said NASA Test Director Charlie Blackwell-Thompson. "Our countdown work is progressing well, the STS-128 flight crew, Discovery and the launch team are ready to go."
With the moon setting to the west at 10:28 p.m. Monday, Discovery's planned launch at 1:36:05 a.m. Tuesday will take place in a fully dark sky, giving area residents and tourists an early morning sky show.
"You know, in this business there are few sights as beautiful as a nighttime launch and I expect this to be a spectacular sight as Discovery roars to life early Tuesday morning and lights up the night sky," said Blackwell-Thompson.
Working by remote control, engineers plan to pump liquid oxygen and hydrogen into tanks supplying Discovery's fuel cells overnight Saturday, allowing NASA to make four launch attempts in five days if necessary.
NASA's Mission Management Team will meet Sunday to review launch processing and the results of an analysis focused on recent problems with electrical switching controllers used aboard the shuttle and in ground test rigs.
A controller aboard Discovery was replaced after a recent malfunction and while the new unit is operating normally, engineers are reviewing past incidents to make sure work-arounds are available in case of additional problems in orbit.
Assuming no major issues are found, NASA will press ahead with the countdown and engineers will roll a protective gantry away from Discovery at 5 a.m. Monday, exposing the shuttle to view and setting the stage for fueling.
If all goes well, engineers will pump a half-million gallons of liquid oxygen and hydrogen rocket fuel into Discovery's external tank starting at 4:11 p.m. Monday.
Discovery's crew - commander Frederick Sturckow, pilot Kevin Ford, flight engineer Jose Hernandez, Patrick Forrester, John "Danny" Olivas, European Space Agency astronaut Christer Fuglesang and space station flight engineer Nicole Stott - plans to begin strapping in around 10:16 p.m.
Shuttle weather officer Kathy Winters said she expects a 70 percent chance of good weather for Discovery's fueling Monday afternoon and launch early Tuesday.
"Our primary concern on launch day is going to be right around the tanking time, that may be an issue if we do have some lightning in the area, and then when we get to launch," she said. "A nice dark sky for a beautiful launch, just a slight concern for showers in the area."
The forecast remains 70 percent "go" if launch slips to Wednesday, dropping to 60 percent Thursday.
11:20 PM, 8/21/09: Shuttle countdown begins
Engineers at the Kennedy Space Center started the shuttle Discovery's countdown Friday at 11 p.m. EDT, setting the stage for launch early Tuesday on a space station assembly mission. Forecasters are predicting a 70 percent chance of good weather for the planned 1:36:05 a.m. launching.
The next countdown status briefing is scheduled for 10 a.m. Saturday. A space station science briefing is on tap Sunday at 1 p.m., followed by a traditional pre-flight news conference around 3 p.m. (exact time TBD).
An updated countdown timeline is posted on the CBS News STS-128 Quick-Look page, along with a launch windows chart, an ascent events summary timeline and a detailed flight plan. The STS-128 edition of the CBS News Space Reporter's Handbook also is available on the Downloads page, along with SpaceCalc, an Excel workbook loaded with useful mission information.
11:10s AM, 8/21/09: Shuttle countdown on tap; weather 70 percent 'go' for Tuesday launch
Engineers at the Kennedy Space Center geared up Friday for the 11 p.m. EDT start of the shuttle Discovery's countdown to launch Tuesday on a space station resupply mission. While some unplanned work will be carried into the countdown, engineers are optimistic and forecasters are predicting a 70 percent chance of good weather.
"We've had a few challenges along the way, but I think we've gotten them behind us," said NASA Test Director Steve Payne. "As of the moment, our systems are in good shape, launch countdown preps are proceeding and we have no new issues to report. The flight crew, the vehicle and the launch team are ready to go."
Engineers plan to load the shuttle's fuel cell system with liquid oxygen and hydrogen overnight Saturday and to rotate a protective gantry away from Discovery around 5 a.m. Monday. If all goes well, the shuttle will be loaded with liquid oxygen and hydrogen rocket fuel starting at 4:11 p.m. Monday and the crew will strap in around 10:16 p.m.
Liftoff is targeted for 1:36:05 a.m. Tuesday, roughly the moment Earth's rotation carries the pad into the plane of the International Space Station's orbit.
The primary goals of the three-spacewalk mission are to deliver some 7.5 tons of science gear, crew supplies and life support gear to the International Space Station, along with ferrying astronaut Nicole Stott to the lab complex and bringing flight engineer Timothy Kopra home in her place.
Engineers worked Friday to close out the shuttle's aft engine compartment after replacement of a suspect electrical harness and to finish a few final items associated with replacement of a hydraulic power unit in Discovery's left solid-fuel booster.
The only remaining technical issue of any significance is an analysis to make sure work-arounds are understood for any potential problems with a control assembly used to route power to various circuits through the shuttle's electrical buses. A faulty controller aboard Discovery was replaced earlier, but similar problems with other test units raised questions about possible generic issues.
NASA's Mission Management Team plans to meet Sunday for a final review of launch processing.
Forecasters are predicting a 70 percent chance of good weather Tuesday and Wednesday, dropping to 60 percent "go" on Thursday. The primary concerns are a chance of lightning near the pad during fueling and showers in the area at launch time.
Assuming a good load for Discovery's fuel cell system, Payne said the shuttle should be able to make four launch attempts in five days.
"It should be a spectacular launch," Payne said. "I'm hoping we put on a good show for you."
2:10 PM, 8/19/09: Shuttle Discovery cleared for Aug. 25 launch (UPDATED at 7 PM with crew arrival)
As expected, senior NASA managers Wednesday formally cleared the shuttle Discovery for launch Tuesday on a space station resupply mission. While some engineers said they favored collecting additional data on the integrity of foam insulation on the shuttle's external tank - work that would trigger a lengthy launch delay - officials said no one objected to pressing ahead for launch at 1:36 a.m. EDT Aug. 25.
"We had lots of discussion about the foam," said Bill Gerstenmaier, chief of space operations at NASA headquarters in Washington. "Some folks wanted some additional testing, some folks had some different opinions about what the data was telling us. But it wasn't a contentious discussion, it was just really an engineering discussion about what we know and what we don't know.
"In the end, we let everyone kind of state their opinions. No one chose to appeal the decision, but there were definitely some differing opinions amongst the group and I think that's really good, that's what we've been trying to get."
Discovery commander Frederick Sturckow, pilot Kevin Ford, flight engineer Jose Hernandez, Patrick Forrester, John "Danny" Olivas, European Space Agency astronaut Christer Fuglesang and space station flight engineer Nicole Stott flew to the Kennedy Space Center Wednesday evening to prepare for launch. Discovery's countdown is scheduled to begin at 11 p.m. Friday.
"Well, good afternoon. It's great to arrive here in Florida for the launch of STS-128," Sturckow said at the Shuttle Landing Facility. "We've been studying and training hard for just about a year now and we're ready to go accomplish this mission. Very happy to be here."
Said Fuglesang, a Swedish astronaut making his second trip to the space station: "Last time I was here two-and-a-half years ago station was just half finished. This time, I'm very much looking forward to come up to space station, which is more or less complete, with a full crew of six. We're bringing up everything we need to sustain it for a long time and do great research up there."
The STS-128 crew at launch pad 39A earlier this month. From left to right:
Commander Rick Sturckow, Danny Olivas, Christer Fuglesang, pilot Kevin
Ford, Nicole Stott, Patrick Forrester, Jose Hernandez. (Photo: NASA)
The only technical issue still under discussion is a failure analysis to determine what caused a power controller aboard the shuttle to malfunction. The controller was replaced, but two similar units recently failed and engineers want to make sure the issue is understood before proceeding. The results of troubleshooting will be presented to NASA's Mission Management Team during an engineering review Sunday.
The primary goals of shuttle mission STS-128 are to ferry Stott to the lab complex to replace outgoing flight engineer Timothy Kopra and to deliver more than seven tons of science equipment, hardware, food and other supplies. Three spacewalks are planned to replace a massive ammonia coolant system tank; to retrieve external experiments; to install a replacement rate gyroscope assembly; to deploy an external hardware storage mechanism; and to install wiring needed for the attachment of a new module next year.
Assuming an on-time launch Tuesday, Discovery will return to the Kennedy Space Center for a landing around 8:40 p.m. on Sept. 6.
A major topic in this week's executive-level flight readiness review was the integrity of the foam insulation on Discovery's external tank, ET-132. An unusual amount of foam fell away from the shuttle Endeavour's tank during launch July 15, most of it from the central "intertank" area separating the hydrogen and oxygen sections of external tank No. 131.
A small amount of foam fell from the base of the left-side bi-pod strut that helps hold the shuttle's nose to the tank and another piece of debris fell from one of the so-called ice-frost ramps on the side of the liquid oxygen section.
The bi-pod foam loss is an understood phenomenon and not considered a major issue. Addressing the intertank foam loss, engineers carried out nearly 200 so-called "plug-pull" tests to check the adhesion of the insulation and no problems were found.
But Endeavour's launch was the second in a row in which foam fell from the same ice-frost ramp on the liquid-oxygen section of the tank. The ice-frost ramps are aerodynamically shaped areas of foam covering fittings that attach pressurization lines to the oxygen section of the tank.
The foam loss during Endeavour's launch presumably occurred because of undetected voids in the insulation. Atmospheric heating during ascent can cause trapped air to expand, popping off overlying foam. Impact-related heat shield damage depends on the size and timing of a release, which can be difficult to model.
NASA managers are extremely sensitive to foam issues in the wake of the 2003 Columbia disaster, but shuttle Program Manager John Shannon said the foam shedding under discussion following Endeavour's flight was minor in comparison.
"I read a couple of comparisons that said this was similar to Columbia," he said. "And of course on Columbia, we had a 2.2-pound piece of foam come off and damage the wing. The loss we had on the last flight that generated all of this discussion over the last two weeks was 0.044 pounds, which is one-fiftieth the size of the Columbia foam.
"That's how close we're looking, that's how sensitive we are. It generated four days of flight readiness review discussion, and a whole lot of work and additional testing. And that's exactly what we want the team to do, to look at it that closely. I feel extremely good about the results of the meeting. I think we have done absolute due diligence on the foam piece of it."
The ramp in question on Discovery's tank was subjected to non-destructive terahertz inspections before the shuttle was moved to the launch pad and no significant voids were seen. But three other ramps, which have no history of foam loss, were not inspected.
At a shuttle program review last week, some engineers recommended hauling Discovery back to the Vehicle Assembly Building for terahertz inspections of the other ramps, a move that would delay launch to around Oct. 17.
Instead, managers ordered additional plug-pull tests and terahertz inspections of the ice-frost ramps on the next tank in the sequence, ET-133. The additional pull tests found no problems. The ice-frost ramp scans of ET-133 detected 10 very small voids, none of which would be expected to result in damaging foam losses.
"Getting the data off the next tank and showing we don't have a big processing issue I think was key to the team accepting the condition," Shannon said.
Characterizing the debate over the foam, Shannon said it was not so much dissension "as it was the team coming in and saying there are other data you can collect, or there are other ways you can slice the data and look at it."
"And we rely on that in order to make a good decision," he said. "We try to reinforce that in the flight readiness process that that's what we expect, we want team members to come in and say there's additional data you can collect, there are additional ways to collect that data. And that was done, and I think that was very helpful."
6:40 PM, 8/17/09: Discovery external tank cleared for launch as is after debate about foam concern; readiness review to continue Wednesday; official launch date not yet set, but internal target is 8/25
After a lengthy technical discussion, NASA managers decided Tuesday the shuttle Discovery's external tank can be safely flown as is, without the need for additional time-consuming inspections of its foam insulation, clearing the way for launch next week on a space station resupply mission. The executive-level flight readiness review ran long and a final decision on whether to proceed with launch or to order a lengthy delay was not expected until the extended meeting concluded Wednesday. But late Tuesday, agency officials speaking through Twitter said "the tank discussion is over and everyone had the chance to offer a viewpoint. At this point, the FRR decided we're OK to fly as is." An official launch date is expected to be set Wednesday, but the internal processing target is Aug. 25 at 1:36 a.m. EDT, one day later than the previous target because of unplanned work at the launch pad.
Discovery's crew - commander Frederick Sturckow, pilot Kevin Ford, flight engineer Jose Hernandez, Patrick Forrester, John "Danny" Olivas, European Space Agency astronaut Christer Fuglesang and space station flight engineer Nicole Stott - plans to fly to the Kennedy Space Center Wednesday evening for the start of Discovery's countdown at 11 p.m. Friday.
Along with ferrying Stott to the lab complex and bringing Timothy Kopra home in her place, the Discovery astronauts plan to deliver critical supplies and equipment, carrying out three spacewalks before landing back at the Florida spaceport around 8:40 p.m. on Sept. 6.A major topic in Tuesday's review was the integrity of the foam insulation on Discovery's external tank, ET-132, following an unusual amount of foam shedding during the shuttle Endeavour's launching July 15. While some engineers said they would prefer additional data, sources said the community was unanimous in agreeing to proceed.
Most of the foam lost from Endeavour's tank fell away from the central "intertank" area separating the hydrogen and oxygen sections of external tank No. 131. A small amount of foam fell from the base of the left-side bi-pod strut that helps hold the shuttle's nose to the tank and another piece of debris fell from one of the so-called ice-frost ramps on the side of the liquid oxygen section.
Engineers carried out more than 170 so-called "plug-pull" tests on the intertank foam of Discovery's tank earlier to test the adhesion of the insulation and no problems were found. The bi-pod foam loss is believed to be an understood condition and not a major threat to damage the shuttle's heat shield.
But Endeavour's launch was the second in a row to experience foam loss from the same ice-frost ramp on the liquid-oxygen section of the tank. The ice-frost ramps are aerodynamically shaped areas of foam covering fittings that attach pressurization lines to the oxygen section of the tank.
The foam loss during Endeavour's launch presumably occurred because of undetected voids in the insulation. Atmospheric friction during ascent can cause trapped air to expand, popping off overlying foam. Impact-related heat shield damage depends on the size and timing of a release, which can be difficult to model.
The ramp in question on Discovery's tank was subjected to non-destructive terahertz inspections before the shuttle was moved to the launch pad and no significant voids were seen. But three other ramps, which have no history of foam loss, were not inspected.
At a shuttle program review last week, some engineers recommended hauling Discovery back to the Vehicle Assembly Building for terahertz inspections of the other ramps, a move that would delay launch to around Oct. 17.
Instead, managers ordered additional plug-pull tests and terahertz inspections of the ice-frost ramps on the next tank in the sequence, ET-133. The additional pull tests found no problems. The ice-frost ramp scans of ET-133 detected 10 very small voids, none of which would be expected to result in damaging foam losses.
But those inspections shed no direct light on the condition of the ramps on Discovery's tank, which cannot be scanned at the launch pad.
The flight readiness review will continue Wednesday, with presentations by the orbiter project and other elements of the shuttle program. But with the external tank cleared for flight and no other major problems under discussion, NASA managers are expected to set Aug. 25 as the official launch date.
1:45 PM, 8/13/09: Shuttle launch depends on external tank test data; second wave of shuttle retirement layoffs looming in October
NASA is pressing ahead with preparations to launch the shuttle Discovery Aug. 24 on a space station resupply mission, but Program Manager John Shannon said today a final decision to proceed will depend on the results of last-minute testing this weekend to verify the integrity of external tank foam insulation.
During the shuttle Endeavour's launch July 15, an unusual amount of foam insulation fell away from external tank No. 131, most of it from the central "intertank" separating the hydrogen and oxygen sections of the tank. A small amount of foam fell from the base of the left-side bi-pod strut that helps hold the shuttle's nose to the tank and another piece of debris fell from one of the so-called ice-frost ramps on the side of the liquid oxygen section.
The bi-pod foam loss is an understood condition, Shannon said, the result of trapped air in foam round a wire bundle that can expand due to atmospheric friction during launch, popping off overlying foam. The problem is magnified with repeated tank loadings and engineers have inspection techniques in place to identify problems.
Engineers still don't know what caused the intertank foam to separate, but 170 plug-pull tests have been carried out in which small cores of foam were pulled with a known force to test the insulation's adhesion to the underlying metal. In all cases, the foam performed at or above specifications.
Even so, engineers ordered a final round of plug-pull tests this weekend from areas of the tank that pose the most risk from a shuttle impact standpoint. That work should be completed this weekend.
The ice-frost ramps are areas of aerodynamically shaped foam around fittings used to attach pressurization lines to the side of the tank. Endeavour's tank was the second in a row to lose foam from the same IFR and engineers want to make sure there are no problems that could affect the IFRs on Discovery's tank, ET-132.
The IFR in question was X-rayed before Discovery's move to launch pad 39A, but three other ice-frost ramps were not. None of those has any history of foam shedding, but some engineers at the shuttle program flight readiness review Monday and Tuesday recommended a roll back to the Vehicle Assembly Building for additional X-ray inspections to make sure there are no problems.
Shannon said the majority of the team opted to proceed with additional testing before next week's executive level FRR.
"Across the board, the vehicle's in great shape," he said. "We're preparing to go fly on Aug. 24, but we have two areas of open work. The first one is to go look at the next tank in line with the X-ray and make sure we don't have a process problem with the ice-frost ramps. The second is to complete the plug pulls and repairs and verify the data (are) good.
"And with that data collected, the majority of the team thought we were in good shape to proceed for the agency flight readiness review. On the intertank, it was complete consensus. On the LO2 ice-frost ramp, about a quarter of the team thought it was still prudent to roll the vehicle back and collect that data on the other three ice-frost ramps. That's what the debate was yesterday."
A rollback to the VAB would delay launch to around Oct. 17, after upcoming Japanese and Russian space station supply and crew rotation missions.
"I would expect that after we get the X-ray data on the next tank, we'll meet again and review the and make sure we're all at a common understanding and go into the flight readiness review with that discussion," Shannon said.
Overnight, engineers used a terahertz X-ray device to examine the ice-frost ramps on external tank No. 133, the next tank in the shuttle launch sequence, to look for any signs of voids in the foam. Air trapped in such voids can expand due to atmospheric friction during launch, causing overlying foam to pop off.
"If they look OK, that's pretty strong evidence you don't have a processing problem," Shannon said. "But there is still some level of doubt. Nobody said we absolutely have to go have that data, where we pull it back (to the VAB) and get the X-ray data. But about a quarter of the engineering community said just to be sure, you should go do this, we recommend you go do this.
"And that'll be the discussion at the agency FRR. We don't require complete consensus, but what we do require is that we hear everybody's position and that we understand their position. I think I understand it very well. All of it has devolved really down to one question: Is there some uncertainty in the process for putting together those ice-frost ramps such that you would need that data? I think the ET-133 data will help us answer that question."
Looking ahead, Shannon said another round of layoffs is planned for October, reducing the shuttle workforce by about 10 percent. An initial round of 900 layoffs was announced at the end of April.
"Two weeks ago, I attended the last space shuttle main engine firing at Stennis (Space Center)," Shannon said. "We have completed the last weld on the last external tank. In January, we will do the last (solid propellant) casting in Utah at the facility out there that produces the solid rocket boosters. In October, we will lay off approximately 1,200 shuttle employees, which is about 10 percent of my current workforce.
"So we are definitely on the pace to shut the program down at the end of 2010. We have communicated all of that, that's not a surprise to anyone."
Counting Discovery's upcoming mission, only seven more flights are planned before the program comes to an end in late 2010 or early 2011. There has been talk of extending shuttle operations to bridge the gap before the debut of a replacement spacecraft, but a presidential commission reviewing manned space flight options for the Obama administration does not appear to favor that approach.
Asked today what it would take to extend shuttle operations, Shannon said "there would be significant work to requalify venders and restart processes. We have had that in the back of our minds ... and we have plans for how we could do that if it is required.
"But we're getting to the point if we don't have a decision late this year, we're going to end up having a gap between when we would stop flying the flights that are currently on the manifest and any new flights that would be out there," he said. "So it's getting very late in the game for us."
6:00 PM, 8/7/09: Shuttle crew straps in for practice countdown; engineers assess external tank ice-frost ramp foam insulation and whether repairs are needed
The shuttle Discovery's crew strapped in for a dress-rehearsal countdown Friday, a milestone on the road to launch around Aug. 24 on a space station resupply mission. Engineers, meanwhile, are continuing a down-to-the-wire assessment of critical insulation on Discovery's external tank in the wake of foam losses during the shuttle Endeavour's launch last month.
Foam losses in three areas were noted during Endeavour's climb to space, most of it falling from the central intertank region of the shuttle's external tank. A small bit of debris also separated from the left-hand bipod mount, where one of two struts holds the nose of the shuttle to the tank, and another piece of insulation fell from a so-called ice-frost ramp on the upper liquid oxygen section of the tank.
Engineers are still not sure what caused the interank foam to separate. But nearly 170 "plug pull" tests were conducted on Discovery's tank - ET-132 - to assess the adhesion of the insulation to the metal structure of the intertank. In every case, the adhesion was normal.
Engineers also believe they understand how the bipod foam came off, the presumed result of voids in the foam insulation around a wiring bundle. But the ice-frost ramp foam loss from a bracket holding an oxygen pressurization line is a somewhat different issue. Endeavour's flight was the second in a row to suffer foam loss from the IFR in question, indicating a potential problem in the way the foam is applied.
The insulation on the pressurization line fitting is applied by injecting foam into a sort of mold. After the foam hardens and the mold is removed, technicians manually shape the foam into the aerodynamic ice-frost ramps visible on the side of the tank.
But the current technique can result in voids in the foam depending on how the mold injection process is carried out. If voids are present, heating from atmospheric friction during the shuttle's climb out of the dense lower atmosphere can cause air trapped in such voids to expand, popping off the overlying foam. Depending on when it is released, such foam can pose an impact hazard to the shuttle's fragile heat shield.
In Discovery's case, engineers X-rayed the IFR in question and saw no evidence of any voids. But engineers at the Marshall Space Flight Center in Huntsville, Ala., are looking into possible remedies for upcoming tanks, including a manual application technique using a different type of foam that might reduce the odds of voids in future flights.
At the same time, shuttle Program Manager John Shannon asked engineers at the Kennedy Space Center to look into how such work could be carried out for Discovery's tank if engineers and managers ultimately conclude a fix of some sort is required.
The IFR cannot be accessed at the launch pad and any such repairs to ET-132 would require a rollback to the Vehicle Assembly Building, delaying launch until mid October at the earliest to avoid conflicts with upcoming Japanese and Russian space station missions.
As of this writing, no final decisions have been made and engineers at the Kennedy Space Center are continuing to process Discovery for launch around Aug. 24 or 25.
But the issue will be reviewed during a shuttle program flight readiness review on Aug. 12, followed by an executive-level review Aug. 18.
8:25 AM, 8/4/09: Shuttle trip to pad slowed by soggy crawlerway (UPDATED at 3:05 p.m. with Discovery on pad)
The shuttle Discovery's slow trip to launch pad 39A turned positively glacial early today while engineers assessed the condition of a soggy crawlerway and discussed whether to proceed or return to the protection of the Vehicle Assembly Building before expected afternoon thunderstorms. They ultimately decided to proceed, driving on the slightly drier edge of the crawlerway and taking nearly 12 hours to cover 3.4 miles.
The shuttle Discovery is hauled to the launch pad,
slowed by soggy conditions. (Credit: Stephen Clark/Spaceflight Now)
Discovery is tentatively scheduled for launch Aug. 25 on a space station resupply and crew rotation mission. Rollout was delayed one day by a discussion of what to do about a suspect check valve in the shuttle's left-side solid-fuel booster that failed during a high pressure leak test.
The valve problem caused a hydraulic pump and one of two auxiliary power units to spin backward, possibly damaging the hardware used to move the rocket's nozzle for steering during the first two minutes of flight. NASA managers decided to proceed with rollout and to replace the hardware at the launch pad.
The 3.4-mile trip to the pad began at 2:06 a.m. EDT. But the roadway that supports NASA's Apollo-era 5.5-million-pound crawler-transporter, the 3-million-pound space shuttle "stack" and its 8.2-million-pound mobile launch platform was saturated with water from recent storms. The massive crawler could do no better than one-quarter to one-third of a mile per hour and frequent stops were required to hose off its huge cleated trucks.
The crawler crew at one point recommended a return to the VAB, concerned that mud, gravel and sand could damage bearings, rollers or other components, leaving the shuttle stranded if repairs were required.
But moving back to the VAB could have triggered a major launch delay - Discovery has to get by the end of the month to avoid significant conflicts with other station missions - and after additional discussion, the crew was able to proceed, driving close to the slightly drier edge of the eight-lane-wide crawlerway.
The shuttle Discovery leaves the Vehicle Assembly Building.
(Credit: Justin Ray/Spaceflight Now)
Five hours into the normally six-hour move, the shuttle was just halfway to the launch pad. But as the morning wore on, the crawler could be seen on NASA television making slow but steady progress, the wet 2,000-pound cleats of its trucks glistening in the sunlight.
A final delay was in store when a pin broke going up the incline to the pad surface. After a stop for repairs, the slow trip continued and the shuttle's mobile launch platform was lowered onto massive support pedestals at 1:50 p.m. to complete the journey.
Discovery commander Frederick Sturckow, pilot Kevin Ford, Jose Hernandez, John "Danny" Olivas, Patrick Forrester, European Space Agency astronaut Christer Fuglesang and space station flight engineer Nicole Stott plan to fly to the Kennedy Space Center early Wednesday to review emergency procedures and participate in a practice countdown Friday.
Assuming the booster hydraulic system repairs can be completed in time, no other major problems develop and NASA managers make the current launch target official, Discovery's countdown will begin Aug. 22, setting up a launch attempt at 1:36 a.m. on Aug. 25.The primary goals of Discovery's three-spacewalk mission are to deliver science racks and other hardware, including a new air revitalization system, to transfer crew supplies, swap out ammonia tanks for the station's cooling system and retrieve a European experiment package.
Stott, making her first flight, will replace flight engineer Timothy Kopra, launched to the station aboard the shuttle Endeavour July 15, as a member of the Expedition 20 crew. Assuming an on-time launch, Discovery's crew, with Kopra riding home in place of Stott, will land back at the Kennedy Space Center Sept. 6.
3:45 PM, 8/2/09: Shuttle rollout on tap Tuesday; CDRA repaired on station (UPDATED 08/03/09 with additional details)
Engineers are readying the shuttle Discovery for rollout to pad 39A early Tuesday, one day later than planned because of work to assess the impact of a check valve failure in the steering system of the ship's left-side solid-fuel booster. The valve problem apparently caused a hydraulic system pump to spin backwards during a high-pressure leak check, possibly damaging the pump and one of the booster's hydraulic power units.
Each shuttle booster is equipped with two independent hydraulic power units, or HPUs, each one consisting of an auxiliary power unit, a hydraulic pump, a fuel supply module and a hydraulic fluid manifold. The two HPUs operate from T-minus 28 seconds through booster separation two minutes after launch, providing the hydraulic power needed to move the nozzles for steering.
Engineers plan to replace the suspect pump, the auxiliary power unit in question and the check valve at the launch pad, working in parallel with normal pre-flight preparations. A booster hydraulic system was replaced at the pad at least once before, but it was many years ago, officials said, and engineers are reviewing plans and procedures.
Rollout to the pad is scheduled to begin at 12:01 a.m. EDT Tuesday. As of this writing, launch on a space station resupply mission remains targeted for around Aug. 25, but there is little contingency time available to handle unexpected problems.
Discovery commander Frederick Sturckow, pilot Kevin Ford, Jose Hernandez, John "Danny" Olivas, Patrick Forrester, European Space Agency astronaut Christer Fuglesang and space station flight engineer Nicole Stott plan to fly to the Kennedy Space Center early Wednesday to review emergency procedures and participate in a practice countdown Friday.
The primary goals of Discovery's three-spacewalk mission are to deliver science racks and other hardware, including a new air revitalization system, to transfer crew supplies, swap out ammonia tanks for the station's cooling system and retrieve a European experiment package.
Stott, making her first flight, will replace flight engineer Timothy Kopra, launched to the station aboard the shuttle Endeavour July 15, as a member of the Expedition 20 crew. This is the final space station crew rotation flight planned for the space shuttle.
Station astronauts, meanwhile, completed a complex repair of the space station's U.S. carbon dioxide removal assembly, or CDRA, late Friday. The device broke down July 25, while the shuttle Endeavour was docked to the outpost. Engineers came up with a manual work-around and then a software patch to return the CDRA to near normal operation, but it broke down again late last week.
The problem ultimately was traced to a short in one of 12 heater pads in one of the two "beds" used to extract carbon dioxide from the crew's air supply. Working through Thursday and Friday, flight engineer Michael Barratt and Robert Thirsk carried out a complex repair to replace a heater controller and to cut wires leading to the shorted heating element. The CDRA was returned to normal operation Friday evening.
11:05 AM, 7/31/09: Shuttle Endeavour lands in Florida
(UPDATED at 12:40 p.m. with quotes from commander; UPDATED at 3:30 p.m. with comments from Wakata)
The shuttle Endeavour glided to a landing at the Kennedy Space Center today, wrapping up a marathon 16-day space station construction mission and bringing Japan's first long-duration astronaut back to Earth after four-and-a-half months in weightlessness.
Dropping out of a partly cloudy sky, commander Mark Polansky pulled the shuttle's nose up just before reaching the runway, pilot Douglas Hurley deployed the spaceplane's landing gear and Endeavour settled to a picture-perfect landing at 10:48:08 a.m. EDT.
The shuttle Endeavour settles to runway 15 after a smooth descent.
(Photo: NASA TV)
Barreling down the runway at more than 200 mph, Hurley released a red-and-white braking parachute, the shuttle's nose dropped to the runway and Polansky guided the ship to a stop on the runway centerline.
"Houston, Endeavour, wheels stopped," he radioed in a traditional post-landing call to mission control.
"Roger wheels stopped, Endeavour. Welcome home," astronaut Alan Poindexter replied from the Johnson Space Center. "Congratulations on a superb mission from beginning to end. Very well done."
"Well, thanks to you and the whole team," Polansky said. "That's what it's all about. And we're happy to be home."
Mission duration was 15 days 16 hours 44 minutes and 58 seconds for a voyage spanning 248 complete orbits and 6.5 million miles since blastoff July 15 from launch complex 39A.
Polansky, Hurley, flight engineer Julie Payette, David Wolf, Christopher Cassidy and Thomas Marshburn doffed their pressure suits and left the shuttle and their crew transport vehicle about an hour-and-a-half after landing, welcomed home by new NASA Administrator Charles Bolden and other senior managers and engineers.
"What a fantastic mission!" Polansky said on the runway after a brief walk-around inspection of Endeavour. "We are thrilled to be a part of a team that is able to accomplish missions like this. ... What can we say but thanks to everybody at the Kennedy Space Center for working so hard on Endeavour. It's a beautiful vehicle and we enjoyed every minute of it. Hopefully we brought it back in good shape.
"We're going to make this short because we'd actually like to go see our families. So thank you all very much."
The shuttle Endeavour's braking chute slows the craft after landing.
(Photo: NASA TV)
Returning space station flight engineer Koichi Wakata, launched to the International Space Station aboard the shuttle Discovery last March, made the return to Earth on the eve of his 46th birthday resting on his back in a recumbent seat on the shuttle's lower deck to ease his return to gravity.
But he apparently had no major problems with his initial re-adaptation, appearing at a crew news conference four hours after landing.
"I feel great," he said. "When the hatch opened, I really smelled the grass from the ground and just glad to be back home. I'm feeling great. Still feeling a little shaky when I walk, but I'm feeling very good."
Wakata's stay in space was extended a month when Endeavour's launch was delayed from June 13 to July 15 by technical problems and bad weather. Asked what he was looking forward to the most after reunions with family and friends, Wakata said sushi, cold noodles and visit to a hot spring back home.
"Tomorrow will be my 46th birthday," he said after landing. "I'm just looking forward to having a lot of sushi and birthday cake. I think it's in production somewhere, so I'm very much looking forward to that.
"You invited your whole crew, right?" Polansky joked.
"Yes," Wakata laughed. "Can you handle raw fish?"
Endeavour's crew ferried Wakata's replacement into orbit - astronaut Timothy Kopra - and carried out five spacewalks to attach an experiment platform to the Japanese Kibo laboratory module, replacing aging solar array batteries and attaching three spare components to the station's main truss.
The astronauts also released a jammed payload attachment mechanism, installed television cameras on the Japanese experiment shelf and made a wiring change to put two of the station's stabilizing gyroscopes on separate circuits, easing concerns about a single failure that could take down both units.
"We got everything accomplished aboard space station that we needed to with this mission," said Bill Gerstenmaier, chief of space operations at NASA headquarters. "The planning was outstanding, the work was excellent, the vehicle performed extremely well.
With Endeavour back on the ground, NASA is pressing ahead with work to ready the shuttle Discovery for launch around Aug. 25 on a mission to deliver supplies and equipment to the space station.
Rollout to launch pad 39A is targeted for Monday, after additional work to test the foam insulation on the central part of Discovery's external tank. The tests were ordered in the wake of problems during Endeavour's launch when an unusual amount of "intertank" foam peeled off during the climb to space.
Most of the debris came off after Endeavour was out of the dense lower atmosphere when the shuttle's heat shield is most vulnerable to impact damage. But engineers want to make sure there is not a generic problem of some sort that might also affect the performance of Discovery's tank.
Engineers already had pull tested some 150 foam cores around the intertank of ET-132, but an additional 18 "plug-pull" tests were ordered Thursday.
Still unresolved is what caused the foam to come off in the first place. It's not yet clear whether a "root cause" must be in hand and understood before Discovery can be cleared for flight or whether the pull tests and data analysis alone will be enough.
Kopra and his new space station crewmates - Expedition 20 commander Gennady Padalka, Michael Barratt, Roman Romanenko, European Space Agency astronaut Frank De Winne and Canadian astronaut Robert Thirsk - hoped to watch Endeavour's landing via television uplinked from mission control.
Barratt and Thirsk continued repair work today to recover use of the station's U.S. carbon dioxide removal assembly, or CDRA, which was knocked out of action last weekend and again Wednesday by a presumed short circuit in a heating element.
The astronauts spent the entire day Thursday trying to repair the complex device before running into questions about how to isolate the suspect heater element. Engineers are hopeful the repairs can be completed later today.