The shuttle Discovery approaches runway 33 at the Kennedy Space
Center. (Photo: Stephen Clark/Spaceflight Now)
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
9:30 AM, 4/20/10, Update: Shuttle Discovery lands in Florida (UPDATED at 11:20 a.m.; crew departs runway; quotes)
The shuttle Discovery, delayed a day by cloudy Florida weather, blazed across the heartland of America Tuesday, gliding to a pinpoint landing at the Kennedy Space Center to close out an extended space station assembly mission.
Approaching the spaceport from the northwest, commander Alan Poindexter took over manual control at an altitude of 50,000 feet, guiding the shuttle through a 200-degree left turn to line up on runway 33. After giving pilot James Dutton a few moments of stick time, Poindexter flew the shuttle to a picture-perfect touchdown at 9:08:35 a.m. EDT.
The shuttle Discovery approaches runway 33 at the Kennedy Space
Center. (Photo: Stephen Clark/Spaceflight Now)
"Wheels stopped, Houston," Poindexter radioed as Discovery rolled to a halt on the 300-foot-wide runway.
"Roger, wheels stopped, Discovery. Welcome home," called astronaut Rick Sturckow from mission control. "Dex, congratulations to you and the crew on an outstanding mission."
"Thanks for the words, it was a great mission, we enjoyed working with you and all the teams in mission control," Poindexter replied. "And we're glad the International Space Station is stocked up again. Thanks a lot."
The 131st shuttle mission covered 238 complete orbits and 6.2 million miles since blastoff April 5 for a mission duration of 15 days two hours 47 minutes and 10 seconds.
Poindexter, Dutton and their crewmates - flight engineer Dorothy Metcalf-Lindenburger, Stephanie Wilson, Japanese astronaut Naoko Yamazaki and spacewalkers Richard Mastracchio and Clayton Anderson - planned to doff their pressure suits and gather on the runway for a traditional walk-around inspection of the shuttle.
All seven astronauts plan to fly back to Houston early Wednesday after reunions with friends and family members.
The Discovery astronauts pose in front of Discovery. (Photo: NASA TV)
Already running a day late because of low clouds at the space center Monday, the astronauts were aiming for a 7:34 a.m. landing in Florida Tuesday, but nearby showers and concern about fog prompted entry Flight Director Bryan Lunney to order a one-orbit wave off.
As the sun came up, showers moved outside NASA's 30-nautical-mile safety zone, fog was minimal and Lunney cleared Poindexter to begin a descent that gave shuttle viewers in the continental United States a rare chance to witness the fiery streak of a shuttle re-entry.
In the wake of the 2003 Columbia disaster, NASA has favored southwest-to-northeast entry trajectories that carry the shuttle above the Pacific Ocean and the Caribbean, avoiding seasonal, potentially dangerous noctilucent clouds in the northern hemisphere.
The favored trajectories also require less propellant and, while not a requirement, keep descending shuttles well away from any densely populated areas in the United States.
Discovery's return was only the second so-called "descending node" entry since 2003. NASA managers ordered the change of plans to give the astronauts more time to complete the station resupply mission and to bring in a daylight landing opportunity at the end of a long flight. The high, icy clouds that can be a concern are not an issue at this time of year.
"The neat thing about the descending opportunities is it's going to come across the country and folks will get a good opportunity, hopefully, to see the orbiter as it goes overhead," Lunney said Sunday.
Discovery plunged back into the discernible atmosphere at an altitude of about 76 miles above the central Pacific Ocean south of the Aleutian Islands at 8:36 a.m., crossing the western Canadian coast near Vancouver at an altitude of about 40 miles.
With the shuttle surrounded by superheated plasma as atmospheric friction reduced its 5-mile-per-second orbital velocity, viewers in the west with a clear sky could expect to see a "streak of white light way up high," Lunney said. "When it's down lower, it's going to be more the glowing cloud plowing through. I think both will be clearly visible" weather permitting.
With its heat shield protecting the shuttle from temperatures of up to 3,000 degrees, Discovery sailed high above Helena, Mont., just west of Casper, Wyo., and across the northeastern corner of Colorado before descending across Kansas, Oklahoma and Arkansas, passing north of Little Rock before continuing across Mississippi, Alabama and Georgia.
The shuttle crossed into Florida and then passed east of Gainesville before beginning its final approach to the Kennedy Space Center.
"It was a beautiful entry this morning," Poindexter said before leaving the runway. "We got the bonus of coming over the entire United States and it was just absolutely gorgeous. The entry track took us over the Rockies and over the midwest and across the Mississippi delta, it was just a fantastic entry.
"The landing back here at the Kennedy Space Center was really nice. It's a beautiful day, it was a great mission and we're just happy to be back here in Florida with Discovery."
Engineers service Discovery after landing. (Photo: NASA TV)
With Discovery back on the ground, engineers at the nearby Vehicle Assembly Building were readying the shuttle Atlantis for an overnight trip to launch pad 39A for liftoff May 14 on another space station assembly mission. It will be the 32nd and final planned flight for Atlantis as NASA faces the shuttle program's last three flights.
The final missions are devoted to delivering as much in the way of spare parts and supplies as possible before the shuttle fleet is retired and the station is dependent on less capable Russian, European and Japanese cargo craft.
Discovery's crew delivered more than 17,000 pounds of supplies, equipment and science gear and staged three spacewalks to replace an ammonia coolant tank o the station's main power truss. The new tank was successfully installed, but flight controllers were unable to pressurize the coolant loop because of trouble with a valve in an associated nitrogen tank.
Mission managers briefly considered asking Mastracchio and Anderson to carry out a fourth spacewalk to install a spare nitrogen tank. But after a detailed assessment, engineers concluded the coolant loop could be safely operated for at least a month without pressurization. As it now stands, the station's crew likely will stage a spacewalk later this spring to install a replacement tank.
8:10 AM, 4/20/10, Update: Discovery braking rockets fired
Flying upside down and backward, commander Alan Poindexter and pilot James Dutton fired the shuttle Discovery's twin braking rockets for two minutes and 57 seconds starting at 8:03 a.m. to begin an hourlong descent to the Kennedy Space Center. After a rare flight across the heartland of America, Poindexter plans to guide the shuttle to a landing on runway 33 at 9:08 a.m. This status report will be updated after landing or as conditions warrant.
6:20 AM, 4/20/10, Update: Shuttle entry delayed one orbit
Concerned about showers and the possible development of fog, entry Flight Director Bryan Lunney ordered the Discovery astronauts to pass up their first Florida landing opportunity Tuesday, delaying re-entry for one orbit to give forecasters more time to assess the weather in Florida and California.
Commander Alan Poindexter and his six crewmates have one more opportunity to land in Florida and three at Edwards Air Force Base in California's Mojave Desert. The second Florida opportunity and the first at Edwards come on the next orbit.
"Dex, we worked it really hard and we just can't get comfortable with the first opportunity so we're going to go ahead and wave off," astronaut Rick Sturckow radioed from mission control just after 6 a.m. EDT. "We're going to continue to look at KSC and Edwards for the next rev."
"Copy, Houston. And we understand about the wave off," Poindexter replied. "That makes sense to us."
For a landing at Edwards, the astronauts would fire Discovery's braking rockets at 7:56 a.m. EDT, setting up a landing on runway 22 at 9:01 a.m. For a landing in Florida, the braking rockets would be fired at 8:02 a.m. for a landing on runway 33 at 9:08 a.m.
The forecast for the Kennedy Space Center calls for a chance of showers within 30 nautical miles of the runway. At Edwards, the forecast is "go," but conditions are breezy with headwinds gusting to 21 knots.
3:50 AM, 4/20/10, Update: Florida forecast 'go,' but fog possible
The Discovery astronauts are working through their pre-entry checklist, rigging the shuttle for landing to close out an extended space station assembly fight. Forecasters are now predicting acceptable weather at the Kennedy Space Center, although fog is a possibility for the first of two Florida landing opportunities.
"Good news, there's a 'go' forecast at KSC," astronaut Rick Sturckow radioed from mission control around 2:30 a.m. EDT. "No precipitation concern inside of 30 miles, all the shower activity's kind of to the east of that 30-mile circle. The main concern is going to be fog. Fog is not in the forecast, but that's what we're having Fergie (astronaut Chris Ferguson) look at for the T-38 (weather assessment) flight."
"So it's going to be few (clouds) at 2,000 (feet), scattered 5,000, scattered 12,000, seven miles vis and the winds are zero-eight-zero (at) four, peak six knots," Sturckow said. "So that's all good news. We'll keep an eye on the fog for the first opportunity."
"We understand, Houston, thanks a lot," commander Alan Poindexter replied from Discovery. "That sounds like a great forecast."
Discovery's crew has two landing opportunities at Kennedy and three at Edwards:
ORBIT...SITE..DEORBIT BURN..LANDING 237.....KSC...06:28:50 AM...07:34:08 AM 238.....EDW...07:56:29 AM...09:01:17 AM ........KSC...08:02:59 AM...09:08:37 AM 239.....EDW...09:30:59 AM...10:35:57 AM 240.....EDW...11:05:39 AM...12:11:06 AM
Sturckow said NASA's backup landing site at Edwards Air Force Base, Calif., also expects good, if breezy, weather "however, later today the wind's going to go up to about 40 knots out there. So we're looking at all this and we'll have more words as we work through the checklist."
"Thanks a lot, Houston, we know you guys are working hard on it," Poindexter said. "We appreciate it."
Updating the crew at 3:40 a.m., Sturckow said Ferguson had "flown around pretty much all over and he didn't see any signs of concern. A little farther away from the SLF (Shuttle Landing Facility), like in Orlando, the vis is down pretty low, so there's fog in the neighborhood and we've just got to keep watching it."
Detailed entry timelines and ground-track charts are posted on the CBS News STS-132 Quick-Look page:
http://www.cbsnews.com/network/news/space/currentglance.html#ENTRY
9:30 PM, 4/19/10, Update: NASA preps for day-late shuttle entry; Atlantis rollout delayed
Along with delaying the shuttle Discovery's return to Earth Monday, bad weather also forced NASA to delay the shuttle Atlantis' rollout to launch pad 39A for work to ready the ship for takeoff May 14 on a space station assembly mission, the shuttle's 32nd and final planned flight.
The 3.4-mile trip from the Vehicle Assembly Building to the seaside launch pad was rescheduled for Tuesday evening, weather permitting.
The shuttle Atlantis in the VAB, ready for its trip to the
launch pad. (Credit: NASA)
Discovery's crew, meanwhile, hoped the weather would be more cooperative Tuesday morning after low clouds and rain blocked two landing opportunities Monday.
Discovery has two more landing opportunities Tuesday at the Kennedy Space Center and three at Edwards Air Force Base in California's Mojave Desert. As with Monday's waved-off attempts, Discovery's path to Florida will carry it over the heartland of America, weather permitting, giving viewers along the way a rare chance to watch a shuttle during re-entry.
Should the crew be diverted to Edwards, viewers in Oregon, western Nevada and California will have a chance to hear the shuttle's sonic booms depending on which landing opportunity might be selected (see the NASA landing charts below for ground tracks and sighting opportunities).
The Spaceflight Meteorology Group at the Johnson Space Center in Houston is predicting somewhat better conditions in Florida Tuesday, with scattered clouds at 5,000 and 10,000 feet, a broken deck of clouds at 25,000 feet, winds out of the northeast at 10 knots with gusts to 15 and a slight chance of showers within 30 nautical miles.
At Edwards, the SMG is predicting breezy conditions, with scattered clouds at 2,500 feet and winds out of 220 degrees at 10 knots with gusts to 17. The winds are expected to increase as the day wears on.
Here are updated entry timelines for the first four landing opportunities (in EDT; best viewed with fixed-width font):
04/20/10 Rev. 237 Deorbit to KSC Deorbit burn: 06:28:50 AM Change in velocity: 204 mph Burn duration: 2:59 Crossrange: 899 sm Range to KSC at atmospheric entry: 4994 sm Turn angle: 335 R Landing: 07:34:08 AM Runway: KSC 15 02:28 AM......Begin deorbit timeline 02:43 AM......Payload bay door radiator stow 02:53 AM......Mission specialists seat installation 02:59 AM......Computers set for deorbit prep 03:03 AM......Hydraulic system configuration 03:28 AM......Flash evaporator cooling system checkout 03:34 AM......Final payload deactivation 03:48 AM......Payload bay doors closed 03:58 AM......Mission control 'go' for OPS-3 entry software load 04:08 AM......OPS-3 transition 04:33 AM......Entry switchlist verification 04:43 AM......Deorbit maneuver update 04:48 AM......Crew entry review 05:03 AM......Commander/pilot don entry suits 05:20 AM......IMU alignment 05:28 AM......Commander/pilot strap in; others don suits 05:45 AM......Shuttle steering check 05:48 AM......Hydraulic system prestart 05:55 AM......Toilet deactivation 06:08 AM......Mission control center 'go' for deorbit burn 06:14 AM......Astronaut seat ingress 06:23 AM......Single APU start 06:28:50 AM...Deorbit ignition 06:31:49 AM...Deorbit burn complete 07:01:49 AM...Atmospheric entry (alt: 75.7 sm; vel: mach 24.9) 07:06:54 AM...1st roll command to right 07:21:08 AM...C-band radar acquisition 07:23:30 AM...1st roll right to left roll reversal 07:27:40 AM...Velocity less than mach 2.5 (alt: 15.5 sm) 07:29:40 AM...Velocity less than mach 1 (alt: 9.8 sm) 07:29:51 AM...335-degree right turn to runway 15 (alt: 50,400 feet) 07:34:08 AM...Landing
Deorbit to KSC on rev 237. (Credit: NASA)
04/20/10 Rev. 238 Deorbit to EDW Deorbit burn: 07:56:29 AM Change in velocity: 205 mph Burn duration: 3:00 Crossrange: 902 sm Range to EDW at atmospheric entry: 4,973 sm Turn angle: 279 L Landing: 09:01:17 AM Runway: EDW 22 07:36 AM......MCC 'go' for deorbit burn 07:42 AM......MS seat ingress 07:51 AM......Single APU start 07:56:29 AM...Deorbit ignition 07:59:29 AM...Deorbit burn complete 08:29:10 AM...Entry interface (alt: 75.6 sm; vel: mach 24.9) 08:34:18 AM...1st roll command to right 08:48:17 AM...C-band radar acquisition 08:50:39 AM...1st right to left roll reversal 08:54:56 AM...Velocity less than mach 2.5 (alt: 15.2 sm) 08:57:07 AM...Velocity less than mach 1 (alt: 8.75 sm) 08:57:32 AM...279-degree left turn to runway 22 (40,100 feet) 09:01:17 AM...Landing
Deorbit to EDW on rev 238. (Credit: NASA)
04/20/10 Rev. 238 Deorbit to KSC Deorbit burn: 08:02:59 AM Change in velocity: 206 mph Burn duration: 3:01 Crossrange: 24 sm Range to KSC at atmospheric entry: 5,139 sm Turn angle: 342 L Landing: 09:08:37 AM Runway: KSC 15 07:42 AM......MCC 'go' for deorbit burn 07:48 AM......MS seat ingress 07:57 AM......Single APU start 08:02:59 AM...Deorbit ignition 08:06:00 AM...Deorbit burn complete 08:36:38 AM...Entry interface (alt: 75.7 sm; vel: mach 24.9) 08:41:45 AM...1st roll command to left 08:48:45 AM...1st left-to-right roll reversal 08:55:37 AM...C-band radar acquisition 09:02:10 AM...Velocity less than mach 2.5 (alt: 15.6 sm) 09:04:11 AM...Velocity less than mach 1 (alt: 9.8 sm) 09:04:16 AM...342-degree left turn to runway 15 (51,200 feet) 09:08:37 AM...Landing
Deorbit to KSC on rev 238. (Credit: NASA)
04/20/10 Rev. 239 Deorbit to EDW Deorbit burn: 09:30:59 AM Change in velocity: 206 mph Burn duration: 3:01 Crossrange: 231 sm Range to EDW at atmospheric entry: 5,103 sm Turn angle: 252 L Landing: 10:35:57 AM Runway: EDW 22 09:10 AM......MCC 'go' for deorbit burn 09:16 AM......MS seat ingress 09:25 AM......Single APU start 09:30:59 AM...Deorbit ignition 09:34:00 AM...Deorbit burn complete 10:04:17 AM...Entry interface (alt: 75.8 sm; vel: mach 24.9) 10:09:29 AM...1st roll command to right 10:18:39 AM...1st right to left roll reversal 10:22:57 AM...C-band radar acquisition 10:29:39 AM...Velocity less than mach 2.5 (alt: 15.3 sm) 10:31:52 AM...Velocity less than mach 1 (alt: 8.6 sm) 10:32:27 AM...252-degree left turn to runway 22 (alt: 36,900 feet) 10:35:57 AM...Landing
Deorbit to EDW on rev 239. (Credit: NASA)
Deorbit to EDW on rev 240. (Credit: NASA)
10:20 AM, 4/19/10, Update: Updated deorbit/landing times
NASA has updated the shuttle Discovery's deorbit and landing times for Tuesday and Wednesday (in EDT; best viewed with fixed-width font):
Orbit...SITE..DEORBIT.......LANDING 04/20 237.....KSC...06:28:50 AM...07:34:08 AM 238.....EDW...07:56:29 AM...09:01:17 AM ........KSC...08:02:59 AM...09:08:37 AM 239.....EDW...09:30:59 AM...10:35:57 AM 240.....EDW...11:05:39 AM...12:11:06 AM 04/21 253.....KSC...06:52:00 AM...07:53:00 AM 254.....EDW...08:19:00 AM...09:21:00 AM ........NOR...08:21:00 AM...09:23:00 AM ........KSC...08:27:00 AM...09:28:00 AM 255.....EDW...09:54:00 AM...10:56:00 AM ........NOR...09:56:00 AM...10:58:00 AM
Updated entry timelines are posted on the CBS News STS-131 Quick-Look page.
9:10 AM, 4/19/10, Update: Shuttle landing delayed 24 hours by cloudy weather
Low clouds obscuring the Kennedy Space Center's shuttle runway forced Flight Director Bryan Lunney to wave off a second attempt to bring the shuttle Discovery back to Earth today. Commander Alan Poindexter and his six crewmates were told to spend an additional day in orbit before making another attempt Tuesday.
"Dex, the folks really worked it hard down here and there was a lot of cause for optimism with (clouds) breaking up all around the SLF (shuttle landing facility)," astronaut Rick Sturckow radioed from Houston. "But at the end of the day, it was just too low of a ceiling, visibility got down to 200 broken at two miles visibility. ... So we're no-go for the deorbit burn."
"We know how hard you guys were working it today and we appreciate everything," Poindexter replied. "We've been there on off-nominal weather days. We appreciate everything you've done and we'll be hopeful for better weather tomorrow."
NASA did not staff its backup landing site at Edwards Air Force Base, Calif., for Monday's landing attempt. But the Mojave Desert test center will be activated Tuesday and Lunney plans to bring Discovery down on one coast or the other, weather permitting.
The forecast for Florida on Tuesday calls for a slight chance of showers near the runway. The weather at Edwards is expected to be clear.
Updated landing timelines for Kennedy and Edwards will be posted later today. In the meantime, here are all the landing opportunities for Tuesday (in EDT; best viewed with fixed-width font):
ORBIT...SITE..TIG...........LANDING 04/20: 237.....KSC...06:31:00 AM...07:33:00 AM 238.....EDW...07:59:00 AM...09:00:00 AM ........KSC...08:07:00 AM...09:08:00 AM 239.....EDW...09:34:00 AM...10:36:00 AM 240.....EDW...11:09:00 AM...12:11:00 AM
7:15 AM, 4/19/10, Update: WAVEOFF - shuttle re-entry delayed at least one orbit
Entry Flight Director Bryan Lunney, assessing low clouds, rain showers and an uncertain forecast, told the Discovery astronauts to delay re-entry for one orbit, setting up a final landing opportunity at 10:23 a.m., weather permitting.
Commander Alan Poindexter and his six crewmates had been preparing for a de-orbit rocket firing at 7:43 a.m. and a landing on runway 33 at the Kennedy Space Center at 8:48 a.m.
But dismal weather, including a low deck of broken clouds and rain within 30- nautical miles of the shuttle's landing strip, prompted Lunney to wave off the first attempt. Forecasters are hopeful conditions will improve as the morning wears on, but the situation is dynamic and difficult to predict.
The crew's second and final landing opportunity calls for a de-orbit rocket firing at 9:17 a.m., setting up a landing at 10:23 a.m.
NASA did not staff its backup landing site at Edwards Air Force Base, Calif. If Discovery doesn't make it back to Florida today, the crew will remain in orbit an extra 24 hours and try again Tuesday.
Here is a timeline of major events for the crew's second opportunity (in EDT):
Rev. 223 Deorbit to KSC 08:57 AM......Mission control 'go' for deorbit burn 09:03 AM......astronauts strap in 09:12 AM......Single APU start 09:17:48 AM...Deorbit ignition 09:17:55 AM...Deorbit burn complete 09:51:56 AM...Atmospheric entry 09:57:18 AM...1st roll command to left 10:12:47 AM...1st left -to-right roll reversal 10:10:30 AM...C-band radar acquisition 10:20:00 AM...Velocity less than mach 2.5 10:22:02 AM...Velocity less than mach 1 10:22:07 AM...274-degree left turn to runway 15 10:23:30 AM...Landing
6:20 AM, 4/19/10, Update: Runway change; updated deorbit time
NASA has updated the deorbit time and runway for the shuttle Discovery's first landing opportunity. Weather permitting, deorbit ignition is now targeted for 7:43:15 a.m. The burn will last two minutes and 59 seconds. In another change, Discovery will target runway 33 instead of 15, requiring a 190-degree right overhead turn around the heading alignment cylinder. Landing remains expected around 8:48:36 a.m.
5:30 AM, 4/19/10, Update: Shuttle crew set for landing; weather marginal
The Discovery astronauts are preparing for re-entry and landing at the Kennedy Space Center today to close out a grueling space station resupply mission. Forecasters are hopeful rain showers will dissipate as the morning wears on, but conditions appear marginal at best.
Commander Alan Poindexter and his six crewmates have two landing opportunities today. The first would require a deorbit rocket firing at 7:43 a.m., setting up a landing on runway 15 at 8:48 a.m. The second opportunity would require a deorbit burn at 9:17 a.m. for a landing at 10:23 a.m.
The Spaceflight Meteorology Group at the Johnson Space Center is predicting a deck of broken clouds at 8,000 feet and a chance for showers within 30 nautical miles of the shuttle runway, a flight rule violation. Conditions appear to be improving somewhat, which may favor the second landing opportunity, but the situation is dynamic.
NASA is not staffing its backup landing site at Edwards Air Force Base, Calif. If Discovery doesn't get down today, the mission will be extended one day and the crew will try again Tuesday. In that case, Edwards would be staffed and entry Flight Director Bryan Lunney would try to bring the shuttle down on one coast or the other. The forecast for Edwards calls for good weather both days.
Here is the timeline for both of today's landing opportunities (in EDT best viewed with fixed-width font):
Rev. 222 Deorbit to KSCEDT...........EVENT 05:13 AM......Mission control 'go' for OPS-3 entry software load 05:23 AM......OPS-3 transition 05:48 AM......Entry switch list verification 05:58 AM......Deorbit maneuver update 06:03 AM......Crew entry review 06:18 AM......Commander, pilot don entry suits 06:35 AM......IMU alignment 06:43 AM......CDR/PLT strap in; other crew dons suits 07:00 AM......Shuttle steering check 07:03 AM......Hydraulic system prestart 07:10 AM......Toilet deactivation 07:23 AM......Mission control 'go' for deorbit burn 07:29 AM......Astronaut seat ingress 07:38 AM......Single APU start 07:43:20 AM...Deorbit ignition 07:46:31 AM...Deorbit burn complete 08:16:59 AM...Entry interface 08:22:15 AM...1st roll command to left 08:35:13 AM...1st roll left to right 08:35:36 AM...C-band radar acquisition 08:44:55 AM...Velocity less than mach 2.5 08:46:56 AM...Velocity less than mach 1 08:47:03 AM...339-degree left turn to runway 15 08:48:36 AM...Landing
Orbit 222 Entry Trajectory. (Credit: NASA)
08:57 AM......MCC 'go' for deorbit burn 09:03 AM......MS seat ingress 09:12 AM......Single APU start 09:17:48 AM...Deorbit ignition 09:17:55 AM...Deorbit burn complete 09:51:56 AM...Entry interface 09:57:18 AM...1st roll command to left 10:12:47 AM...1st left -to-right roll reversal 10:10:30 AM...C-band radar acquisition 10:20:00 AM...Velocity less than mach 2.5 10:22:02 AM...Velocity less than mach 1 10:22:07 AM...274-degree left turn to runway 15 10:23:30 AM...Landing
Orbit 223 Entry Trajectory. (Credit: NASA)
01:15 PM, 4/18/10, Update: Astronauts pack for Monday landing
The Discovery astronauts tested the shuttle's re-entry systems Sunday and packed up for landing Monday at the Kennedy Space Center, weather permitting, to close out a space station resupply mission with a fiery dawn plunge across the heartland of America.
Commander Alan Poindexter and pilot James Dutton plan to fire Discovery's braking rockets for three minutes and 11 seconds starting at 7:43:20 a.m. EDT Monday, slowing the ship by about 217 mph and setting up a landing on runway 15 at the Florida spaceport at 8:48:36 a.m. A second opportunity is available one orbit later at 10:23:30 a.m.
There are no technical issues of any significance with the space shuttle, but forecasters are predicting an overcast sky with a broken deck of clouds at 8,000 feet and a chance for rain showers within 30 nautical miles of the runway. Conditions are expected to improve slightly on Tuesday, but good weather is expected both days at Edwards Air Force Base, Calif., NASA's backup landing site.
NASA is not staffing Edwards Monday and if the weather prevents a Florida landing, Discovery's flight will be extended another day and the crew will try again Tuesday. In that case, Edwards would be staffed and available.
"It's always a great time to spend (an extra day) on orbit," Poindexter told a reporter earlier Sunday. "We're confident the folks in Houston and the folks in Florida will do everything they can to get us home when the weather will allow it."
Entry flight director Bryan Lunney said Discovery has enough on-board supplies to remain in orbit until Wednesday at the latest. But NASA holds the final day in reserve to handle technical problems, so if Discovery doesn't get down Monday, Lunney will attempt to bring the crew home, on one coast or the other, Tuesday.
"We'll see what happens overnight," he said. "If it violates our flight rules and it's not a good day to go land, then we'll wave off until Tuesday."
If the Florida weather cooperates Monday or Tuesday, it likely will be the last chance for viewers in the continental United States to witness the fiery streak of a shuttle re-entry.
In the wake of the 2003 Columbia disaster, NASA has favored southwest-to-northeast entry trajectories that carry the shuttle above the Pacific Ocean and the Caribbean, avoiding seasonal, potentially dangerous noctilucent clouds in the northern hemisphere.
The favored trajectories also require less propellant and, while not a requirement, keep descending shuttles well away from any densely populated areas in the United States.
Discovery's return is the second so-called "descending node" entry since 2003. NASA managers ordered the change of plans to give the astronauts more time to complete the station resupply mission and to bring in a daylight landing opportunity at the end of a long flight. The high, icy clouds that can be a concern are not an issue at this time of year.
"The neat thing about the descending opportunities is it's going to come across the country and folks will get a good opportunity, hopefully, to see the orbiter as it goes overhead," Lunney said.
Assuming an on-time descent, Discovery will plunge back into the discernible atmosphere at an altitude of about 76 miles above the central Pacific Ocean south of the Aleutian Islands at 8:17 a.m., crossing the western Canadian coast "just above where the Winter Olympics were," Lunney said.
"The vehicle will be about (43 miles up) at that point, traveling at a speed of about Mach 23, moving very fast, very high," Lunney said. "We took a quick look at the weather forecast and we think the western side of the United States will be relatively clear. So hopefully folks there will get a view. The eastern side might be a little bit more cloudy, so hopefully you'll get a hole and you can see it through the clouds."
With the shuttle surrounded by superheated plasma as atmospheric friction reduces its 5-mile-per-second orbital velocity, viewers in the west will see a "streak of white light way up high," Lunney said. "When it's down lower, it's going to be more the glowing cloud plowing through. I think both will be clearly visible if the clouds allow it to be."
Here are detailed timelines for both Florida landing opportunities Monday (in EDT; best viewed with fixed-width font):
Rev. 222 Deorbit to KSCEDT...........EVENT 03:43 AM......Begin deorbit timeline 03:58 AM......Radiator stow 04:08 AM......Mission specialists seat installation 04:14 AM......Computers set for deorbit prep 04:18 AM......Hydraulic system configuration 04:43 AM......Flash evaporator checkout 04:49 AM......Final payload deactivation 05:03 AM......Payload bay doors closed 05:13 AM......Mission control 'go' for OPS-3 entry software load 05:23 AM......OPS-3 transition 05:48 AM......Entry switch list verification 05:58 AM......Deorbit maneuver update 06:03 AM......Crew entry review 06:18 AM......Commander, pilot don entry suits 06:35 AM......IMU alignment 06:43 AM......CDR/PLT strap in; other crew dons suits 07:00 AM......Shuttle steering check 07:03 AM......Hydraulic system prestart 07:10 AM......Toilet deactivation 07:23 AM......Mission control 'go' for deorbit burn 07:29 AM......Astronaut seat ingress 07:38 AM......Single APU start 07:43:20 AM...Deorbit ignition 07:46:31 AM...Deorbit burn complete 08:16:59 AM...Entry interface 08:22:15 AM...1st roll command to left 08:35:13 AM...1st roll left to right 08:35:36 AM...C-band radar acquisition 08:44:55 AM...Velocity less than mach 2.5 08:46:56 AM...Velocity less than mach 1 08:47:03 AM...339-degree left turn to runway 15 08:48:36 AM...Landing
Orbit 222 Entry Trajectory. (Credit: NASA)
08:57 AM......MCC 'go' for deorbit burn 09:03 AM......MS seat ingress 09:12 AM......Single APU start 09:17:48 AM...Deorbit ignition 09:17:55 AM...Deorbit burn complete 09:51:56 AM...Entry interface 09:57:18 AM...1st roll command to left 10:12:47 AM...1st left -to-right roll reversal 10:10:30 AM...C-band radar acquisition 10:20:00 AM...Velocity less than mach 2.5 10:22:02 AM...Velocity less than mach 1 10:22:07 AM...274-degree left turn to runway 15 10:23:30 AM...Landing
Orbit 223 Entry Trajectory. (Credit: NASA)
ORBIT...SITE..TIG...........LANDING 04/19: 222.....KSC...07:43:20 AM...08:48:36 AM 223.....KSC...09:17:48 AM...10:23:30 AM 04/20: 237.....KSC...06:31:00 AM...07:33:00 AM 238.....EDW...07:59:00 AM...09:00:00 AM ........KSC...08:07:00 AM...09:08:00 AM 239.....EDW...09:34:00 AM...10:36:00 AM 240.....EDW...11:09:00 AM...12:11:00 AM 04/21: 253.....KSC...06:52:00 AM...07:53:00 AM 254.....EDW...08:19:00 AM...09:21:00 AM ........NOR...08:21:00 AM...09:23:00 AM ........KSC...08:27:00 AM...09:28:00 AM 255.....EDW...09:54:00 AM...10:56:00 AM ........NOR...09:56:00 AM...10:58:00 AM
7:30 AM, 4/17/10, Update: Shuttle crew preps Discovery for undocking (UPDATED at 9:30 AM with undocking)
The Discovery astronauts bid their station counterparts farewell early Saturday, sharing a final round of hugs and handshakes before moving back aboard the shuttle and undocking from the lab complex. Separation occurred at 8:52 a.m. EDT as the two spacecraft sailed 220 miles above Papua, New Guinea.
"Houston and station, Discovery, physical separation," shuttle commander Alan Poindexter radioed as the docking systems disengaged.
"Discovery, departing," Expedition 23 flight engineer Soichi Noguchi called out, ringing the ship's bell in the lab's Harmony module.
"Dex you and your crew were excellent guests, we loved having you here, you helped us leave the station in a better place than when you got here," flight engineer Timothy Creamer radioed a moment later. "We'll miss you. Come back soon."
"Thanks, T.J., we enjoyed every minute of it," Poindexter replied. "Thanks for the great hospitality. We'll talk to you soon."
A sequential still video shot of the space station from Discovery. (Credit: NASA TV)
Discovery, passing below the International Space Station, passes high above the coast of Brazil. (Credit: NASA TV)
With shuttle pilot James Dutton at the controls on Discovery's aft flight deck, Discovery pulled straight away in front of the station before beginning a 360-degree photo-documentation fly around. Once back at the starting point in front of the outpost, Dutton will fire Discovery's maneuvering rockets and depart the area.
"The pilot's big moment of glory is getting to do the fly around of the space station," Dutton said in a NASA interview. "So we'll undock, back away around 400 to 450 feet in front of the space station and then begin to fly a maneuver over the top in front of the space station, essentially complete a 360-degree arc around the space station. Then we'll continue to maneuver to essentially break out of our orbit with the station, so we'll get a real panoramic view. As big as the station is now, I can't really imagine how breathtaking that will be, getting to see it from every perspective."
But the public will have to wait until Discovery lands to fully share that perspective. While occasional still photos from the shuttle are possible using the shuttle's S-band communications system, the failure of the orbiter's Ku-band antenna earlier in the mission will prevent routine live television from the shuttle for the remainder of its mission.
Discovery passes behind the International Space Station.
(Credit: NASA TV)
Discovery's mission, with seven crew members, marks the last time NASA expects 13 people aboard the International Space Station. The agency's final three shuttle flights feature six-person crews and there are no plans to boost the station's complement above the current half dozen.
"This is time when we have to say goodbye to our friends and colleagues," said Expedition 23 commander Oleg Kotov, one of three Russians on the station crew. "It was an excellent crew, shuttle Discovery flight 19A did excellent job, we enjoyed working with them and it's really, really sad to let them go, but it's time. Let me say again, thank you very much, we're really grateful for your help and your job you did for us. Thanks a lot."
Shuttle commander Alan Poindexter (blue shirt) embraces
Expedition 23 commander Oleg Kotov during a brief
farewell ceremony.(Credit: NASA TV)
Poindexter thanked the station crew for help with "a very successful docked mission and that is in large part due to the preparation that you did ahead of time."
"You treated us with just the utmost hospitality and we felt welcome the whole time," he said. "We hope we didn't tear up your house too much. We tried to do a good job of cleaning when we left. It was a great docked mission, very successful, we had three just outstanding EVAs and a lot of great robotics. The transfer team was just fantastic.
"Again, I want to thank you and your crew for all the help you gave us with transfer," Poindexter said. "It was just great. We're sorry to go. I know we'd all like to stay much longer, but we have to let you guys get back to your normal routine and get ready for (the next shuttle visit). So with that, we want to say thanks again and we hope to see you soon back home. Take care."
The combined 13-member shuttle-station crew shares a final round
of hugs and handshakes. (Credit: NASA TV)
The two crews then exchanged embraces and handshakes and the shuttle crew floated back aboard the orbiter for the last time. Hatches were closed around 6:30 a.m. to set the stage for undocking.
"Adios, amigos," Noguchi called as Discovery departed. "Sayonara."
Poindexter and his crewmates face a relatively light schedule for the rest of the day. A final heat shield inspection, normally carried out just after undocking, was performed Friday so the crew could use the station's Ku-band communications system to downlink the laser scans and video.
On Sunday, Poindexter, Dutton and flight engineer Dottie Metcalf-Lindenburger will test Discovery's re-entry systems while their crewmates pack up and rig the ship for entry.
Landing back at the Kennedy Space Center is targeted for 8:51 a.m. Monday, but the weather could cause problems. The Spaceflight Meteorology Group at the Johnson Space Center in Houston is predicting showers within 30 miles of the Kennedy Space Center at landing time Monday with a slight chance of showers Tuesday. The forecast for Edwards Air Force Base, Calif., calls for good weather Monday and Tuesday.
Weather permitting, Discovery's re-entry trajectory will carry the orbiter above the heartland of America during its descent to the Kennedy Space Center, possibly the last time viewers in the continental United States will have a chance to witness the fiery streak of a shuttle entry. Detailed ground track charts and timelines are posted on the CBS News STS-131 Quick-Look page.
Here is a timeline of the remainder of today's activity (in EDT and mission elapsed time; includes revision M of the NASA television schedule; best viewed with fixed-width font):
EDT........DD...HH...MM...SS...EVENT 08:37 AM...12...02...15...37...Sunset 08:52 AM...12...02...31...00...UNDOCKING 08:52 AM...12...02...31...05...Maintain corridor 08:53 AM...12...02...32...00...Initial separation 08:54 AM...12...02...32...40...ISS holds current attitude 08:57 AM...12...02...36...00...50 ft 08:59 AM...12...02...38...00...75 ft 09:12 AM...12...02...50...51...Sunrise 09:20 AM...12...02...58...35...ISS Ku band un-park 09:21 AM...12...03...00...00...400 ft; start flyaround 09:30 AM...12...03...09...30...600 feet 09:32 AM...12...03...11...30...Shuttle directly above ISS 09:40 AM...12...03...18...58...Noon 09:44 AM...12...03...23...00...Shuttle directly behind ISS 09:55 AM...12...03...34...30...Shuttle directly below ISS 10:07 AM...12...03...46...00...Shuttle directly ahead of ISS 10:07 AM...12...03...46...00...Separation burn 1 (1.5 fps radial burn) 10:08 AM...12...03...47...05...Sunset 10:35 AM...12...04...14...00...Separation burn 2 (3.0 fps retrograde burn) 10:36 AM...12...04...15...00...Group B computer powerdown 10:40 AM...12...04...18...35...US solar arrays unlocked 11:30 AM...12...05...09...00...Mission status briefing on NTV 11:56 AM...12...05...35...00...EVA unpack and stow 12:41 PM...12...06...20...00...OBSS stow 01:56 PM...12...07...35...00...Ku antenna stow 02:00 PM...12...07...39...00...Post-MMT briefing on NTV 03:21 PM...12...09...00...00...ISS crew sleep begins 04:21 PM...12...10...00...00...STS crew sleep begins 05:00 PM...12...10...39...00...Daily highlights reel on NTV
Earlier Saturday, the astronauts downlinked "crew choice" video, including scenes in the Japanese Kibo laboratory module where Expedition 23 flight engineer Soichi Noguchi and Discovery astronaut Naoko Yamazaki demonstrated the pleasures of zero gravity, tossing a baseball and demonstrating tightrope walking. Yamazaki also gave Noguchi a haircut, using clippers with an attached vacuum hose.
Yamazaki "walks" a tightrope in the Kibo module. (Credit: NASA TV)
Noguchi and Yamazaki play catch. (Credit: NASA TV)
Yamazaki gives Noguchi a haircut. (Credit: NASA TV)
Yamazaki in more traditional Japanese garb. (Credit: NASA TV)
12:30 PM, 4/16/10, Update: Cargo module moved to shuttle; astronauts inspect heat shield, prep for undocking Saturday
The Discovery astronauts parked the Leonardo cargo module in the shuttle's payload bay Friday and carried out a final heat shield inspection to set the stage for undocking Saturday from the International Space Station.
The inspection of the shuttle's carbon composite nose cap and wing leading edge panels normally is carried out after the shuttle leaves the station. But the failure of Discovery's Ku-band antenna earlier in the mission forced the crew to move the examination up one day so the laser scan data could be downlinked to mission control using the station's communications system.
Complicating the timeline, problems with the berthing mechanism that held Leonardo in place on the space station delayed the module's transfer back to the shuttle. Instead of berthing the cargo carrier Thursday as originally planned, the astronauts, using the station's robot arm, left it parked just above the shuttle's cargo bay overnight and completed the installation early Friday.
The shuttle Discovery, with the Leonardo module back in the cargo
bay, and the International Space Station. (Credit: NASA TV)
"This has been a set of fun-filled days, to say the least, for the on-orbit crew and for the operations team," said Flight Director Richard Jones. "We've been working through quite a few late-breaking issues, but we handled each one in stride. I must say, I'm very proud of the teams on how well they handled and responded to all the adversities we've been faced with over the past few days."
The Leonardo berthing went smoothly and "we finished up this shift by accomplishing what we call the docked late inspection," Jones said. "We had to perform these docked late inspections as a result of the Ku failure we've got on board Discovery. We weren't going to be able to downlink any of the imagery that we collected had we done this after undocking like we normally do. So we accomplished that today. The crew literally just flew through it, they were well ahead of the timeline."
It will take most of the day to downlink the multi-gigabyte data files to analysts at the Johnson Space Center in Houston. Jones said Discovery's crew likely would be cleared for undocking Saturday even if the analysis is not complete.
"Typically, it's a little bit more than 24 hours before we have a final decision on whether or not there are any issues with respect to the wing leading edge or the nose cap areas," he said. "Do we have to have that data in hand before we undock? No, we don't. What we will have are some preliminary assurances that what we have shows no surprises."
As with all station assembly missions, the shuttle has enough fuel on board to re-rendezvous with the lab complex if any major problems are detected.
The astronauts plan to go to bed around 4:21 p.m. Wakeup is scheduled for 12:21 a.m. Saturday. After a final joint meal and a brief farewell ceremony with the space station's six-member crew, the Discovery astronauts will move back into the orbiter and close the hatch around 6:11 a.m. Undocking is targeted for 8:52 a.m.
Here is an updated timeline of today's activity (in EDT and mission elapsed time; includes revision L of the NASA television schedule; best viewed with fixed-width font):
EDT........DD...HH...MM...SS...EVENT 04/16 04:00 PM...11...09...39...00...Ascent highlights video on NTV 04:21 PM...11...10...00...00...STS crew sleep begins 05:00 PM...11...10...39...00...Daily highlights reel on NTV 04/17 12:21 AM...11...18...00...00...Crew wakeup 02:21 AM...11...20...00...00...ISS daily planning conference 04:56 AM...11...22...35...00...Joint crew meal 05:56 AM...11...23...35...00...Farewell ceremony 06:09 AM...11...23...48...00...Sunrise 06:11 AM...11...23...50...00...Rendezvous tools checkout 06:11 AM...11...23...50...00...Hatches closed 06:37 AM...12...00...16...06...Noon 06:41 AM...12...00...20...00...Orbiter docking system leak checks 06:51 AM...12...00...30...00...Centerline camera install 07:05 AM...12...00...44...11...Sunset 07:11 AM...12...00...50...00...Group B computer powerup 07:16 AM...12...00...54...35...US arrays in undock config 07:36 AM...12...01...14...35...Maneuver to undocking attitude 07:40 AM...12...01...19...26...Sunrise 08:06 AM...12...01...44...35...Maneuver complete 08:08 AM...12...01...47...32...Noon 08:36 AM...12...02...14...35...ISS Ku antenna park complete 08:37 AM...12...02...15...37...Sunset 08:52 AM...12...02...31...00...UNDOCKING 08:52 AM...12...02...31...05...Maintain corridor 08:53 AM...12...02...32...00...Initial separation 08:54 AM...12...02...32...40...ISS holds current attitude 08:57 AM...12...02...36...00...50 ft 08:59 AM...12...02...38...00...75 ft 09:12 AM...12...02...50...51...Sunrise 09:20 AM...12...02...58...35...ISS Ku band un-park 09:21 AM...12...03...00...00...400 ft; start flyaround 09:30 AM...12...03...09...30...600 feet 09:32 AM...12...03...11...30...Shuttle directly above ISS 09:40 AM...12...03...18...58...Noon 09:44 AM...12...03...23...00...Shuttle directly behind ISS 09:55 AM...12...03...34...30...Shuttle directly below ISS 10:07 AM...12...03...46...00...Shuttle directly ahead of ISS 10:07 AM...12...03...46...00...Separation burn 1 (1.5 fps radial burn) 10:08 AM...12...03...47...05...Sunset 10:35 AM...12...04...14...00...Separation burn 2 (3.0 fps retrograde burn) 10:36 AM...12...04...15...00...Group B computer powerdown 10:40 AM...12...04...18...35...US solar arrays unlocked 11:30 AM...12...05...09...00...Mission status briefing on NTV 11:56 AM...12...05...35...00...EVA unpack and stow 12:41 PM...12...06...20...00...OBSS stow 01:56 PM...12...07...35...00...Ku antenna stow 02:00 PM...12...07...39...00...Post-MMT briefing on NTV 03:21 PM...12...09...00...00...ISS crew sleep begins 04:21 PM...12...10...00...00...STS crew sleep begins 05:00 PM...12...10...39...00...Daily highlights reel on NTV
7:00 PM, 4/15/10, Update: Cargo module detached from station; berthing in shuttle cargo bay on tap early Friday
The Leonardo cargo module was detached from the International Space Station late Thursday after a lengthy delay due to problems with a berthing mechanism controller.
Because the move came late in the crew's day, the module, attached to the station's robot arm, was parked overnight in a "low hover" position just above the shuttle's payload bay. The astronauts plan to complete the installation early Friday, after enjoying an extra hour of sleep.
"We had problems with the common berthing mechanism on the space station," said John McCullough, chief of the flight director's office at the Johnson Space Center. "This is the controller that drives the bolts that holds the MPLM (cargo module) on the station.
"We had a connector that was not fully aligned as it should be and had a sheared set pin on it. And so the crew taped that down with some Kapton tape that folks went off and looked at and made sure was going to be OK for the duration that port was going to be exposed to space. We checked out the mechanism again, we power cycled everything and brought it back up and everything worked very well."
He said flight controller proceeded slowly because "we wanted to make sure we were very comfortable pressing ahead."
"We actually de-mated some connectors, looked at some of the welded areas and made sure everything was in good shape," he said. "And indeed it was, and when we re-activated it, it worked very well. They went through the depress of the vestibule between the module that's coming off and the station to allow us to have a clean demate and that went very well as well."
After the module is locked in Discovery's cargo bay early Friday, the astronauts will press ahead with a final heat-shield inspection, using an inspection boom on the end of the shuttle's robot arm to examine the shuttle's carbon composite nose cap and wing leading edge panels.
Late inspections normally are carried out after a shuttle undocks from the station, using the orbiter's Ku-band antenna system to relay laser scan data to the ground. But Discovery's Ku-antenna system failed earlier in the mission, forcing NASA to implement a docked inspection instead, using the station's Ku-band communications system to downlink the data.
If all goes well, Discovery will undock from the space station around 8:52 a.m. Saturday and land back at the Kennedy Space Center at 8:48 a.m. Monday.
1:00 PM, 4/15/10, Update: After extensive troubleshooting, astronauts press ahead with delayed work to move cargo module back to shuttle
After extensive troubleshooting to resolve an issue with a berthing mechanism controller, the Discovery astronauts were tentatively cleared to press ahead with work to move the Leonardo cargo module from its port on the space station back to the shuttle's cargo bay for return to Earth.
The Italian-built cargo module's main hatch was closed at 3:38 a.m. EDT Thursday and the astronauts installed four common berthing mechanism controller assemblies, the electrical devices that route computer commands to 16 motor-driven bolts and latches holding the module in place.
But the crew reported problems with an electrical connector and telemetry indicated trouble with one of the four controller assemblies. Work to prepare the vestibule between Leonardo and its docking port for depressurization was put on hold while ground controllers scrambled to figure out what was wrong.
Additional testing was inconclusive. All four controllers appeared to power up normally using a secondary power source, but engineers were not immediately able to determine what caused the original problem. They did not want to proceed if there was any chance of another failure, or unexpected behavior, during the unbolting process.
But after extensive discussions, flight directors told the crew to press ahead with preparations for vestibule depressurization. If the controllers passed subsequent checks, the crew could be cleared to grapple the module with the station's robot arm, unbolt it from the Harmony module's Earth-facing hatch and move it to Discovery's cargo bay.
But it will depend on how late in the crew's day the work might go. If the remaining work goes smoothly, the module could be back in the cargo bay before the crew's planned bed time. Flight controllers held open the option of delaying berthing until Friday morning if the work runs long.
Either way, the astronauts will carry out a final heat shield inspection Friday.
The late inspection normally is carried out after the shuttle undocks from the station, using the orbiter's Ku-band antenna system to relay laser scan data to the ground. But Discovery's Ku-antenna system failed earlier in the mission, forcing NASA to implement a docked inspection instead, using the station's Ku-band communications system to downlink the data.
If all goes well, Discovery will undock from the space station around 8:52 a.m. Saturday and land back at the Kennedy Space Center at 8:48 a.m. Monday.
7:50 AM, 4/15/10, Update: Cargo module move on hold pending resolution of berthing system controller problem
Work to move the Leonardo cargo module from its port on the space station's Harmony module back to the shuttle Discovery's cargo bay for return to Earth has been delayed because of a problem with the common berthing mechanism holding it in place.
A space station module hatch showing four controller panel
assemblies. (Credit: Boeing)
The berthing mechanism features four control panel assemblies that route computer commands to drive 16 motorized bolts locking the cargo module in place. The astronauts and ground controllers are troubleshooting an electrical continuity problem with one of the controller panel assemblies.
The flight plan called for the cargo module to be detached starting around 8:40 a.m., but the move is on hold pending resolution of the berthing mechanism problem.
01:00 AM, 4/15/10, Update: Cargo module move on tap; 4th spacewalk ruled out
Flight controllers have decided not to add a fourth spacewalk to the shuttle Discovery's mission to replace a nitrogen tank in the International Space Station's ammonia coolant system, concluding the system can safely operate for an extended period despite a stuck valve preventing normal pressurization. Astronaut Megan McArthur radioed the news to shuttle commander Alan Poindexter just after the crew woke up around 12:21 a.m. EDT.
"We have some big picture words for you on the plan this morning," she called from mission control. "The decision has been made to not perform a fourth EVA on this mission. Analysis shows the current ATA (ammonia tank assembly) config is OK for an extended period. Once everybody's awake and you've had some coffee, you can get with the ISS crew and call down on the big loop to the ISS MCC (mission control center) and they'll give you some more detailed words."
"OK, Megan, that sounds great, thanks a lot," Poindexter replied. "Again, we appreciate all the extra effort that went into quickly looking at that option. We're glad the station will be fine without the extra EVA here for a little bit. Thanks a lot."
A fourth spacewalk would have required a one-day mission extension and delayed Discovery's undocking from Saturday to Sunday. As it now stands, the Discovery astronauts will press ahead with their normal flight plan, undock on Saturday and land back at the Kennedy Space Center early Monday.
The shuttle Discovery and the International Space Station pass
220 miles above western Australia early Thursday. (Credit: NASA TV)
The major item on the shuttle crew's agenda Thursday was wrapping up equipment transfers between the station and the Leonardo cargo module that was carried up aboard Discovery and attached to the lab complex the day after docking.
The Italian-built module was launched with more than 17,000 pounds of equipment and supplies for the space station. For its return, it will be packed with nearly 11,000 pounds of equipment, trash and no-longer-needed material.
The astronauts plan to leave the cargo module for the last time around 3 a.m. Around 7:30 a.m., astronaut Stephanie Wilson and shuttle pilot James Dutton will grapple the module with the station's robot arm. A little more than an hour later, the common berthing mechanisms will disengage and Wilson will move the cargo module back to the shuttle's cargo bay. The module should be locked in place by around 10 a.m.
The astronauts are scheduled to go to bed around 4:20 p.m., just after President Barack Obama delivers a major space policy speech at the Kennedy Space Center. During an orbital news conference Wednesday, Poindexter said the crew was following news coverage of the president's visit but had not made plans to watch any of the proceedings.
At the Johnson Space Center in Houston Wednesday, engineers spent the day carrying out a detailed analysis to determine whether a fourth spacewalk should be added to Discovery's mission to replace a nitrogen tank in the space station's external cooling system.
One of the primary goals of Discovery's mission was to replace one of two ammonia coolant tanks on the station's main power truss. Before staging the first of three spacewalks to swap out the tanks, flight controllers sent commands to close a nitrogen pressurization vent valve. After the new tank was installed, engineers attempted to reopen the nitrogen valve but it failed to respond and appears to be stuck in the closed position.
The nitrogen is used in a bellows system to maintain the proper pressure when the ammonia coolant expands due to solar heating and contracts due to cooling. Solar heating currently is increasing as the angle between the sun and the plane of the station's orbit changes. Without the nitrogen pressurization system, engineers worried there was a chance coolant loop A could be damaged due to the ammonia's unchecked expansion.
Before that happens, flight controllers could simply shut down electrical systems and deactivate coolant loop A. But that last-resort option would cripple the space station.
As it turned out, an exhaustive analysis showed coolant loop A can handle the expected temperature increases over the next few weeks even without normal pressurization. That will allow the station crew to defer swapping out the nitrogen tank until a quieter period when it will have less impact on station operations.
"We could possibly do a (station crew) spacewalk between space shuttle flights, so maybe we go do a spacewalk before STS-132 (the next flight) that's coming up in May," said Flight Director Ed Van Cise. "Maybe there's enough flexibility for us to do it after STS-132, maybe the engineers and the program managers determine the best thing to do is actually try to do something during the STS-132 mission because there are more people, more resources available."
Additional details will be posted as they become available.
Here is an updated timeline of today's activity (in EDT and mission elapsed time; includes revision J of the NASA television schedule):
EDT........DD...HH...MM...EVENT 04/15 12:21 AM...09...18...00...Crew wakeup 01:51 AM...09...19...30...ISS daily planning conference 02:36 AM...09...20...15...Middeck transfers 02:51 AM...09...20...30...Cargo module (MPLM) egress 03:06 AM...09...20...45...MPLM deactivation 03:26 AM...09...21...05...MPLM vestibule demate 04:56 AM...09...22...35...MPLM vestibule depress 05:21 AM...09...23...00...Education robotics taping (shuttle arm) 05:51 AM...09...23...30...Education robotics taping (station arm) 05:51 AM...09...23...30...EVA transfer to shuttle 06:11 AM...09...23...50...Crew meals begin 07:26 AM...10...01...05...Station arm (SSRMS) grapples MPLM 08:41 AM...10...02...20...MPLM uninstall 09:56 AM...10...03...35...MPLM install in payload bay 10:11 AM...10...03...50...SSRMS ungrapples MPLM 10:30 AM...10...04...09...Mission status briefing on NTV 11:11 AM...10...04...50...Heat shield inspection procedures review 01:30 PM...10...07...09...Presidential visit to KSC; preempts NTV 01:41 PM...10...07...20...Evening planning conference 03:51 PM...10...09...30...ISS crew sleep begins 04:21 PM...10...10...00...STS crew sleep begins 06:15 PM...10...11...54...NTV mission coverage resumes 07:00 PM...10...12...39...Daily highlights on NTV 07:45 PM...10...13...24...Flight director update on NTV 04/16 12:21 AM...10...18...00...Crew wakeup
01:10 PM, 4/14/10, Update: NASA ponders additional spacewalk, mission extension, for Discovery's crew
Flight controllers have been unable to re-open a jammed valve in a nitrogen tank assembly needed to pressurize one of the International Space Station's two ammonia coolant loops. Faced with increasing temperatures that could force flight controllers to shut down half the station's systems later this month, NASA managers are considering the possibility of extending Discovery's mission by another day and adding a fourth spacewalk to install a spare nitrogen tank assembly. Another option, assuming the valve defies ongoing troubleshooting efforts, would be to defer the replacement work until after Discovery departs, using space station astronauts instead.
"Right now, we are trying to put together the plan, we're looking at work we had done for this on previous flights and trying to put the procedures together," said space station Flight Director Ron Spencer. "The earlier the decision the better. We're still trying to finalize exactly when we have to have that decision. But it's no later than tomorrow."
The shuttle Discovery and the International Space Station.
(Credit: NASA TV)
The current flight plan calls for the Discovery astronauts to move a large cargo module back to the shuttle on Thursday. A final heat shield inspection would be carried out Friday before undocking Saturday and landing back at the Kennedy Space Center Monday.
If a spacewalk is added to the flight, it likely would be carried out Saturday. Under that scenario, undocking would be re-targeted for Sunday and landing would be delayed to Tuesday morning.
Spencer said the astronauts had been informed of the possibility of an additional spacewalk, but he stressed no final decisions had been made.
The space station features two independent coolant loops that use ammonia circulating through huge radiators to dissipate the heat generated by the station's electronic systems. Each loop is fed by a large tank of ammonia that includes an internal bellows pressurized by nitrogen. That pressurization system allows the loops to handle the periodic expansion and contraction of the ammonia coolant due to temperature changes in orbit.
The ammonia tank on the left side of the station's power truss, part of coolant loop B, was replaced by an earlier shuttle crew. The Discovery astronauts replaced the tank on the right side in coolant loop A. Other than alignment problems and trouble getting a few bolts to engage, the tank swap went well and there were no indications of any major issues. But flight controllers were unable to re-open the main nitrogen valve needed to re-pressurize coolant loop A.
Overnight, engineers turned on heaters to warm the valve up, they tried cooling the valve and even adjusting the back pressure in the system. Nothing worked, and the valve remains closed.
"So far, we have been unable to re-open that valve," said Spencer. "We opened that valve on flight day one to get the system to a higher pressure before we took the ammonia tank out and then on flight day four, we closed that valve so we could vent the jumpers for the crew to do the EVA disconnections.
"And since then, we've been unable to re-open that valve, which we first attempted to do after the EVA yesterday. So folks are continuing to troubleshoot that problem on the ground to see if there's other things we can try. In the meantime, we are also pursuing work on EVA options to possibly replace the nitrogen tank assembly. Options we are working on include possibly extending the mission by one day and adding a fourth EVA or to perform a (station crew) EVA if the continued ground troubleshooting is unsuccessful.
"So we'll keep working this problem. We're also working to see how long we can fly station in this configuration before we'd have to do an EVA. So there's a lot of work going on right now to figure out how to fix this problem, figure out what our risk is with this problem and how long we have until we have to correct it."
The issue is pressing because of the changing orientation of the station's orbit with respect to the sun.
Later this month, that so-called "beta-angle" between the sun and the plane of the station's orbit will increase to the point where more sunlight will fall on the station for longer periods. Without pressurization, coolant loop A would not be able to compensate for the expansion of the ammonia coolant and likely would have to be shut down. Shutting down a coolant loop would force flight controllers to shut down half the station's electrical systems.
Complicating the issue for NASA, coolant loop A provides cooling for the electronics associated with the station's robot arm. If coolant loop A is shut down for any reason, a spacewalk using the arm would not be possible, which may increase the pressure to add a spacewalk to Discovery's mission.
Spencer said two spare nitrogen tank assemblies are mounted on the station and available for use if needed, one on the left side of the power truss and one on the right. The hardware making up coolant loop A is on the right side of the truss.
One advantage of adding a nitrogen tank swap out to Discovery's mission is that spacewalkers Rick Mastracchio and Clay Anderson have already trained to do similar tasks with the ammonia tank.
"This task has a lot of similarities associated with the ammonia tank replacement," Spencer said. "The EVA crew on this mission are familiar with the fluid connections, the electrical connections and handling a large (component) in space. The nitrogen tank assembly is not as big as the ammonia tank assembly, but it's still fairly large. So there is an experience base there that we may choose to take advantage of if EVA is necessary."
On the downside, he said, an additional spacewalk would put a certain amount of stress on a crew that already has worked through three grueling spacewalks. The mission already has been extended one day to permit a late heat shield inspection before Discovery's undocking.
"The concerns are, number one, mission length," Spencer said. "We already have a 13-day mission with three EVAs and in this case, it would be the same EVA crew going out to do the fourth EVA. So, we are concerned a little bit about crew fatigue. Normally, if we have four EVAs on a mission, normally it's not the same crew doing all four of them.
"Also, of even bigger concern is procedure shelf life. We spend months developing the procedures for the EVAs we plan to do and we also have procedures canned for certain contingencies. But this is not one of those we had canned as a contingency to do during a shuttle mission. Luckily, we've done these nitrogen tank change outs twice before and so we'll be looking at those procedures. ... We want to make sure we get it right if we're going to go out there."
12:45 PM, 4/13/10, Update: Engineers troubleshoot stuck nitrogen valve in coolant system
Engineers are troubleshooting a stuck valve in a nitrogen tank assembly that's needed to pressurize a new ammonia coolant tank installed on the space station by the Discovery astronauts.
If ground commanding does not resolve the problem, a spacewalk by the station astronauts could be required to install a spare nitrogen tank assembly to avoid a major powerdown due to higher temperatures caused by the changing orientation of the station's orbit with respect to the sun.
"The valve that we had a problem with is in the nitrogen tank assembly, which feeds nitrogen to pressurize the ammonia system, not in the ammonia tank assembly itself," said space station Flight Director Ron Spencer. "We do have two spare nitrogen tank assemblies on orbit if we have to swap those out. And if we did do that, it would be an EVA-required task.
"The engineers right now are looking at what else can be done to troubleshoot prior to going to that option. We do have a couple of things we might be able to try, ground commanding wise, to try to get this valve to be successful prior to going to that option."
The space station features two independent coolant loops that use ammonia circulating through huge radiators to dissipate the heat generated by the station's electronic systems. Each loop is fed by a large tank of ammonia that includes an internal bellows that is pressurized by nitrogen.
As the ammonia expands and contracts due to orbital temperature swings, the pressurized bellows compensates.
The two coolant loops were launched dry and then filled with ammonia in orbit when the station's power truss was assembled. Both loops were then pressurized with independent nitrogen tank assemblies. One of the two depleted ammonia tanks was replaced during an earlier shuttle mission. The tank used by the right-side coolant loop was replaced by the Discovery astronauts.
The new tank was put in place during a spacewalk Sunday and connected to the loop's nitrogen and ammonia lines earlier Tuesday. But commands to open the nitrogen valve were not successful.
Spencer said two spare nitrogen tank assemblies are mounted on the station and available for use if needed. The problem is not an immediate crisis, but engineers want to resolve the issue as soon as possible because of the always-changing nature of the space station's orbit.
The orbit is tilted 51.6 degrees to the equator and the angle between the sun and the plane of the orbit - the beta angle - periodically increases and decreases. The beta angle currently is increasing, meaning higher temperatures can be expected.
"What happens in high beta periods is the sun will be off to one side of station during the course of an entire daylight pass instead of overhead with a more regular cycling of temperatures," Spencer said. "So whatever side it's on will tend to heat up during the course of all those daylight passes and the other side will tend to cool down."
Ammonia readily expands due to temperature increases, Spencer said, "and so the concern is once you get to a certain beta angle, the expansion of the ammonia will exceed the capability of the radiators and without the nitrogen in there pressurizing the system, activating the bellows, you can't take as much swing in the total volume of ammonia that you have. So we'd have to shut down the ammonia system prior to that. And folks are going to be taking a harder look at when that is."
Engineers hope to resolve the valve problem, one way or the other, before high temperatures force flight controllers to shut the coolant loop down and along with it, half the station's systems.
"We do get to a higher beta region in April and folks are going to have to be looking really hard to see if we can make it through that period or not," Spencer said. "And I don't know yet whether we can make it."
While a spacewalk by the station crew is always an option, it is a last resort because of the planning required and the impact on other activity. Complicating the near-term picture is the planned launch of the shuttle Atlantis on May 14.
Spencer said it may be possible to coax the stuck valve open by cycling a nitrogen isolation valve that was closed earlier in the mission in preparation for the ammonia tank swap out.
"Going EVA to fix this problem is not the first option," Spencer said. "We do have engineers looking at it right now and there's going to be a couple of other things we can try ... to see if that'll help free this valve. EVA is the last option."
9:00 AM, 4/13/10, Update: Spacewalk No. 3 ends
Astronauts Rick Mastracchio and Clay Anderson wrapped up a six-hour 24-minute spacewalk Tuesday, repressurizing the space station's Quest airlock module at 8:38 a.m. EDT after hooking up a new ammonia coolant tank and moving a depleted tank to the shuttle DIscovery's cargo bay for return to Earth.
Problems bolting the old tank down in the shuttle's payload bay forced the crew to forego retrieval of an experiment platform attached to the Columbus lab module and defer work to tighten up a slightly loose radiator servicing fixture.
But the major objectives of the spacewalk were accomplished, including retrieval of no-longer-needed debris shields and get-ahead work for installation of an S-band antenna system on an upcoming flight.
Rick Mastracchio and Clay Anderson return to the space station's
Quest airlock module after a six-hour 24-minute spacewalk. (Photo: NASA TV)
"All right, very good job to the conclusion of EVA0-3," called spacewalk coordinator Dottie Metcalf-Lindenburger. "It's been awesome working with you guys, this is a really nice job, Stephanie (Wilson) and Jim (Dutton) also with all the robotics."
"Well thanks, Dottie," Mastracchio replied, thanking the engineers who trained them at the Johnson Space Center in Houston.
"And Discovery copies all your kind words for the ground," Stan Love called from mission control. "We'd also like to extend our thanks and congratulations to all of you on the completion of three challenging but wonderfully executed EVAs. ... You guys are EVA super heroes."
Flight controllers, however, are continuing to troubleshoot problems with a valve in the new ammonia tank that is preventing nitrogen gas from pressurizing the system. As of this writing, details are sketchy and it's not known what might be required to resolve the issue.
This was the 143rd spacewalk devoted to station assembly and maintenance since construction began in 1998, the seventh so far this year and the third of three planned by the Discovery astronauts. It was the sixth spacewalk for both Mastracchio and Anderson, who now rank 21st and 22nd respectively on the list of most experienced spacewalkers.
Total space station EVA assembly time now stands at 893 hours and 33 minutes. The total for the Discovery astronauts through three spacewalks is 20 hours and 17 minutes while Mastracchio now has logged 38 hours and 30 minutes of EVA time, two minutes more than Anderson.
This was the final planned spacewalk scheduled for a flight by the shuttle Discovery. As it now stands, the orbiter's next mission - it's final flight - does not include any EVAs.
6:40 AM, 4/13/10, Update: Depleted ammonia tank moved to shuttle's cargo bay; more bolt problems encountered (UPDATED with successful tank attachment)
Four hours into a planned six-and-a-half-hour spacewalk, astronauts Rick Mastracchio and Clay Anderson have connected feed lines to a new ammonia coolant tank on the International Space Station; retrieved a set of no-longer-needed debris shields; and moved a depleted coolant tank to the shuttle Discovery's cargo bay for return to Earth.
"We have a good ammonia tank in Discovery. Great work, guys," spacewalk coordinator Dottie Metcalf-Lindenburger radioed at 5:26 a.m. as the old tank was bolted down in the shuttle's cargo bay.
But that was before Mastracchio attempted to tighten bolt No. 1, running into problems getting the attachment mechanism to line up properly. As a result, the bolt, one of four needed to secure the tank to its carrier plate, would not drive all the way in at the approved torque settings of Mastracchio's power tool.
Clay Anderson, left, and Rick Mastracchio, right, prepare to mount a
depleted ammonia tank at the back of Discovery's cargo bay.
(Photo: NASA TV)
Another view of the ammonia tank being moved into position
by the space station's robot arm. (Photo: NASA TV)
A helmet cam view of a misaligned bolt mechanism. (Photo: NASA TV)
Mastracchio and Anderson, visible at the back of Discovery's
cargo bay, struggling with balky ammonia tank bolts. (Photo: NASA TV)
"And Discovery for EVA, for Rick, I'm wondering if it's possible to get a wrist mirror view of what exactly is causing that spherical bearing to hang up?" asked Stan Love in mission control.
"I think it's a misalignment," Mastracchio said. "I don't think there's anything in the way, I think it's a misalignment. I can back the bolt out and rotate the clevis and take another look."
"Houston copies all," Love said. "We're talking."
A few minutes later, Love told the spacewalkers to remove bolt No. 3 in a bid to get enough play in the system to properly align bolt No. 1. After a bit of a struggle, Mastracchio finally was able to drive bolt No. 1 into place.
Anderson then attempted to re-tighten bolt No. 3 but he was unable to get the required number of turns at the approved torque settings. Using a torque multiplier, however, he was able to apply enough force to drive the bolt home.
"Now I can finally say good job! We have the ammonia tank in the payload bay," said Metcalf-Lindenburger. "Nice job, you guys."
Flight controllers, meanwhile, ran into problems with an apparently stuck valve in the new ammonia tank assembly. Nitrogen gas is used to push ammonia through the cooling system's plumbing but the valve problem held up that process, prompting troubleshooting on the ground.
Installing the new 1,700-pound ammonia tank and moving the depleted tank from the International Space Station to Discovery were the major objectives of the crew's three spacewalks. Trouble with the bolt mechanisms caused problems in the crew's second spacewalk when alignment issues with the new tank took and hour and a half to resolve.
2:25 AM, 4/13/10, Update: Spacewalk No. 3 begins
Running about an hour ahead of schedule, astronauts Rick Mastracchio and Clay Anderson switched their spacesuits to battery power at 2:14 a.m. EDT Tuesday, officially kicking off the Discovery crew's third and final spacewalk.
"It's a beautiful day to go EVA," called spacewalk coordinator Dottie Metcalf-Lindenburger from the shuttle's flight deck.
The first two hours of the spacewalk will be devoted to connecting fluid lines to a new ammonia coolant tank that was installed on the space station Sunday and moving a partially depleted ammonia tank from the station to the shuttle Discovery for return to Earth.
The astronauts also will move no-longer-needed debris shields into the station's airlock, retrieve an experiment rack from the Columbus laboratory module and perform a few "get-ahead" tasks to save time for future assembly crews.
9:30 PM, 4/12/10, Update: Astronauts set for final spacewalk
Astronauts Rick Mastracchio and Clay Anderson are set for a third and final spacewalk Tuesday to complete the installation of a new ammonia coolant tank aboard the International Space Station. The astronauts also will mount a depleted tank in the shuttle Discovery's cargo bay for return to Earth and retrieve no-longer-needed debris shields.
The spacewalk is scheduled to begin at 3:11 a.m. EDT Tuesday, although Mastracchio and Anderson could begin earlier if their preparations go smoothly.
The shuttle Discovery and the space station pass high above the
Red Sea and the Sinai Peninsula on April 10. (Photo: NASA TV)
This will be the 143rd spacewalk devoted to station assembly and maintenance since construction began in 1998, the seventh so far this year and the third of three planned by Discovery's crew. Overall, it is the sixth spacewalk for both Mastracchio and Anderson.
For identification, Mastracchio, call sign EV-1, will be wearing a suit with red stripes around the legs. Anderson, EV-2, will be wearing an unmarked spacesuit.
The astronauts ran into problems during a spacewalk Sunday to mount a new ammonia tank on the space station. Getting a sticky bolt to engage took longer than expected and as a result, Anderson and Mastracchio were forced to defer hooking the tank up to the station's ammonia lines and retrieving space debris impact shields mounted on a storage deck.
"We've got two roll-over tasks that were originally planned as part of EVA-2 that are going to be added to the front end of EVA-3," said shuttle Flight Director Mike Sarafin. "Specifically, the ammonia tank quick-disconnect hook-up that we'll perform at the very beginning of the EVA."
The astronauts could have made those connections at the end of their second spacewalk but there would not have been enough time to decontaminate their suits in the event of even a small ammonia leak.
"So they'll pick up the fluid QD hook ups at the very beginning of this third spacewalk and that'll hook up the brand new ammonia tank to the International Space Station," Sarafin said. "Following that, they'll go get the orbital debris shields off of the external stowage platform No. 2 and temporarily stow those in the airlock. After they do that, they'll go on and essentially proceed with the remainder of EVA-3, in large part what was planned pre-flight."
After stowing a grapple fixture used to help move the new ammonia tank Mastracchio and Anderson will "get the old ammonia tank that's temporarily stowed on the outside of the (station) and return that to the shuttle's payload bay for return to Earth," Sarafin said.
Astronauts Stephanie Wilson and James Dutton, operating the station's robot arm from inside the Destiny module, will move the old ammonia tank to the back of Discovery's cargo bay where Mastracchio and Anderson will be waiting to bolt it in place on the same cargo carrier used by new coolant tank during launch.
After stowing a few tools, Anderson will retrieve an experiment carrier platform from the European Space Agency's Columbus lab module and Mastracchio will perform get-ahead preps for a spare S-band antenna assembly that will be installed on the station's upper Z1 truss during an upcoming shuttle mission.
Finally, Mastracchio will double-check the mounting of a radiator servicing fixture that was installed during the second spacewalk.
"We noticed it was wobbling a little bit," Sarafin said. "We're not sure if we actually torqued it down a little bit too fast because of the type of bolt that that uses or if they didn't tighten it down enough. So they're going to go out and troubleshoot that and make sure there's a good structural connection. That'll essentially wrap up our third and final spacewalk of the flight."
Because of the additional work added to the EVA-3 timeline, the astronauts will defer two other planned tasks to service an external camera and a hand-like attachment for the station's robot arm. Both tasks will be added to future spacewalks.
Inside the space station, meanwhile, the astronauts are pressing ahead with work to move supplies and equipment from the Leonardo cargo module into the lab complex. Russian engineers, meanwhile, are troubleshooting problems with the Elektron oxygen generator in the Russian segment of the station.
Space station Flight Director Ed Van Cise said the problem was not a pressing issue and that the station has plenty of supplies in the near term while the Elektron issue is resolved.
In a bit of good news, replacement of a component in the station's U.S water recycling system appears to have resolved a different problem and Van Cise said the hardware is now processing water normally.
"That replacement went very well," he said. "Last night, we started our first processing cycle (and) I'm happy to report the water processing system is completely functioning, everything is working very well. So we have fresh recycled drinking water for the crew, water to provide to the oxygen generator should we ever need it and we're in very good shape."
Here is an updated timeline of today's activity (in EDT and mission elapsed time; includes revision I of the NASA television schedule; best viewed with fixed-width font):
EDT........DD...HH...MM...EVENT 10:21 PM...07...16...00...STS/ISS crew wakeup 10:56 PM...07...16...35...EVA-3: 14.7 psi repress/hygiene break 11:46 PM...07...17...25...EVA-3: Airlock depress to 10.2 psi 04/13 12:46 AM...07...18...25...MPLM transfers resume 01:36 AM...07...19...15...EVA-3: Spacesuit purge 01:51 AM...07...19...30...EVA-3: Spacesuit prebreathe 02:41 AM...07...20...20...EVA-3: Crew lock depressurization 03:11 AM...07...20...50...EVA-3: Spacesuits to battery power 03:16 AM...07...20...55...EVA-3: Airlock egress/setup 03:26 AM...07...21...05...EVA-3/EV-1: Ammonia tank (ATA) connections 03:26 AM...07...21...05...EVA-3/EV-2: Debris (MMOD) shield retrieval 03:56 AM...07...21...35...EVA-3/EV-1: MMOD shield retrieval 04:11 AM...07...21...50...EVA-3: Adjustable grapple fixture stow 04:41 AM...07...22...20...EVA-3: Payload bay setup 05:11 AM...07...22...50...EVA-3: ATA install on cargo carrier 05:56 AM...07...23...35...EVA-3EV-1: Grapple bar removal 05:56 AM...07...23...35...EVA-3/EV-2: Station arm (SSRMS) setup 06:26 AM...08...05...00...EVA-3/EV-2: LWAPA experiment platform retrieval 06:56 AM...08...35...00...EVA-3/EV-1: LWAPA install 07:26 AM...08...01...05...EVA-3/EV-1: Z1 S-band antenna preps 07:26 AM...08...01...05...EVA-3/EV-2: SSRMS cleanup 08:11 AM...08...01...50...EVA-3/EV-1: S1 radiator grapple fixture adjust 08:26 AM...08...02...05...EVA-3/EV-2: Get aheads 09:11 AM...08...02...50...EVA-3: Cleanup and ingress 09:41 AM...08...03...20...EVA-3: Airlock repressurization 09:56 AM...08...03...35...Spacesuit servicing 11:30 AM...08...05...09...Mission status briefing on NTV 12:01 PM...08...05...40...ISS daily planning conference 02:51 PM...08...08...30...ISS crew sleep begins 03:21 PM...08...09...00...STS crew sleep begins 04:00 PM...08...09...39...Daily video highlights reel on NTV 07:45 PM...08...13...24...Flight director's update 11:21 PM...08...17...00...Crew wakeup
9:50 AM, 4/12/10, Update: Russian president calls station for Cosmonautics Day; suggest space summit discussion
Russian President Dmitry Medvedev called the International Space Station early Monday to mark the 49th anniversary of Yuri Gagarin's historic flight, suggesting an international space summit to discuss ongoing and future cooperative ventures on the high frontier.
"Space is our highest priority, regardless of how hard the economic situation is in the country," Medvedev said in translated remarks. "Space will always remain our priority. This is not just somebody's interpretation, it's our official state position. I am here in my presidential office and when addressing you, I can confirm again the significance of space for the government."
"We want to thank you again for today's holiday," station commander Oleg Kotov replied.
All six Expedition 23 crew members - Kotov, Alexander Skvortsov, Mikhail Kornienko, Tracy Caldwell Dyson, Timothy Creamer and Soichi Noguchi - gathered for the conversation in the U.S. Destiny laboratory module.
"On behalf of all of us here on the International Space Station, including our shuttle colleagues, we just want to wish everyone congratulations on this historic day," Caldwell Dyson told the Russian president. "It means as much to us for the event of Yuri's first launch as it does for all of the people involved in making this space program possible. We're all filled with gratitude and appreciation. Congratulations to all of you."
The space station crew gathers to chat with Russian President
Dmitry Medvedev. Back row, left to right: Timothy Creamer,
Tracy Caldwell Dyson and Soichi Noguchi. Front row:
Alexander Skvortsov, commander Oleg Kotov and Mikhail
Kornienko. (Photo: NASA TV)
Medvedev told the space station crew that in the early years of the space program, "development of cosmonautics was based on ideology and now, this is the area where we should try to assist each other in creating the mechanisms that will yield collective results. And this cooperation, I believe, is extremely important for the future, taking into account that space programs become more and more complicated, more and more costly, and the goals that we set become more and more complicated.
"No country can develop space alone, we need to combine our efforts and we need to talk about it more often," he said. "So maybe we could have some sort of international meeting, maybe at the heads of governments level. Because we talk about various issues, such as tackling all kinds of challenges, dangers and hazards that humanity is facing these days, various disarmament programs, etc., but there is a very important and positive factor that unites us all. So maybe it would be good to have a summit, maybe at the heads of governments level, for the countries that are working in space. So see, I have a very good idea on this holiday. What do you think? We could invite you to participate as well."
Kotov called the International Space Station "a great example of international cooperation where we have two completely different technical schools, Russian and U.S., and we combine our effort, we found the interfaces not only for machines but also for humans and we've created this wonderful, fully functional station ... and that is something that should be used in the future.
"Together, we have created a single organism," Kotov said. "The crew functions as one body even though it consists of representatives from different countries. We have had a European astronaut on board, we have Japanese astronauts on board right now, we have American astronauts, Russian, and we understand each other perfectly, we don't have any conflicts and I hope this will be true also regarding our cooperation everywhere else."
"Oleg, those are very good words, it's nice to hear that," Medvedev replied. Then he changed the subject, saying "I think it will be a mistake if I don't ask you some simple questions. How's life?"
"Well, it's like one of the most popular questions that we're asked - what do you like best in space?" Kotov said. "And my answer is always two things: weightlessness and the view out of the window. Also, just life in this three dimensional space, where walls and floor and ceiling become all the same. That's very interesting, and it takes changing your mind the way you think about your surroundings."
Medvedev asked if the absence of gravity caused any problems for the station crew.
"I can tell you honestly in my first flight, I noticed one month into the flight I had this feeling as though I had been living in space and weightlessness my entire life, it became such a natural part of my thinking that I didn't have any problems," Kotov said.
"Everything was so natural, so pleasant, so comfortable, you get used to all the minor negative details of being in weightless, you begin to enjoy the positives tremendously. And that's something you don't forget and your body remembers that. It was interesting. After I came back to Earth, I was uncomfortable, actually, experiencing Earth's gravitation. To me, it was strange to see the people not only walking on the surface of the planet, but also running. It seemed very difficult."
Medvedev asked about the food on the International Space Station, wondering "are they feeding you well?"
"Food in space is different from the ideas people have based on what they knew in the 60s or 70s," Kotov said. "The food becomes more and more similar to what we eat on Earth. We don't have any tubes. We do have cans and the variety is pretty good. Because we're using the resources of all the space agencies, we have a very international cuisine. We have Japanese food, we have American food, European style, no complaints here."
10:30 PM, 4/11/10, Update: Astronauts take time off
The Discovery astronauts looked forward to a half day off early Monday to relax, share a meal with their space station counterparts and enjoy the view from 220 miles up. Later in the day, they will resume cargo transfer work before gearing up for a third and final spacewalk early Tuesday.
Monday is the 49th anniversary of cosmonaut Yuri Gagarin's historic launch on the first manned space flight and the 29th anniversary of the U.S. shuttle program's maiden voyage. Russian space officials planned to call station commander Oleg Kotov, Alexander Skvortsov and Mikhail Kornienko to mark Cosmonautics Day and the Gagarin anniversary.
"Tomorrow's a really historic day," said station Flight Director Ed Van Cise. "First, the crew's going to get a half day off, they've been very busy and will be very busy for the rest of the week, so we're giving them a little bit of time off.
"But tomorrow's April 12 and that is CosmonauticsÊDay for Russia and for all our Russian partners and crew members, it commemorates the first human being to fly in space, Yuri Gagarin. He launched in (1961) on April 12."
Cosmonautics Day and the shuttle anniversary "is just a good day in general to reflect on the fact that we have a lot of amazing things going on in space flight now," Van Cise said. "We have four women in space for the first time ever, we have two Japanese (astronauts) in space for the first time ever and we have three Russians living long term on space station for the first time. So there are a lot of firsts going on in space right now and tomorrow's going to be a chance to commemorate all those different things.
Later Monday, the Discovery astronauts will participate in round-robin interviews with reporters on Earth before calling it a day. Rick Mastracchio and Clay Anderson plan to spend the night in the space station's Quest airlock module at a reduced air pressure to prepare for a planned six-and-a-half-hour spacewalk early Tuesday.
The primary goals of the mission's three EVAs are to install a new ammonia coolant tank in the space station's main power truss and to move a partially depleted tank to Discovery's cargo bay for return to Earth.
The new tank was moved from the shuttle to a temporary mounting point during the crew's initial spacewalk Friday. The old tank was removed and temporarily mounted on an astronaut equipment cart during a second spacewalk early Saturday and the new tank was moved into its place.
But Anderson and Mastracchio had problems getting the new tank bolted down and because of time lost resolving that issue, they were unable to hook up ammonia and nitrogen pressurization lines. They also ran out of time to retrieve a set of no-longer-needed debris shields and move them into the station for return to Earth aboard Discovery.
Those tasks will be added to the final spacewalk Tuesday, along with a few lower-priority get-ahead items if time is available.
"We will complete connecting the fluid lines to the new ammonia tank," Van Cise said. "We'll bring those shields in and we will take the old tank ... with the space station (robot) arm and secure it into the payload bay of the shuttle.
"And then we'll have a couple of other items we'll be doing at the tail end. For example, there's (an experiment) platform out on the Columbus module, we'll be taking that off Columbus and putting that in the payload bay so we can bring that home."
Mastracchio and Anderson also will install two radiator servicing fixtures to go along with two that were installed Saturday and possibly perform a few other minor get ahead tasks if time is available.
Here is an updated timeline of today's activity (in EDT and mission elapsed time; includes revision H of the NASA television schedule; best viewed with fixed-width font):
EDT........DD...HH...MM...EVENT 04/11 09:51 PM...06...15...30...Crew wakeup 11:31 PM...06...17...10...Russian PAO event 04/12 12:01 AM...06...17...40...ISS daily planning conference 12:31 AM...06...18...10...Robot arm maneuver 12:51 AM...06...18...30...Crew off duty 05:21 AM...06...23...00...Joint crew meal 06:26 AM...07...05...00...MARES stowage configuration 06:41 AM...07...20...00...Japanese PAO event 06:51 AM...07...30...00...Cargo transfers resume 07:21 AM...07...01...00...EVA-3: Tools configured 08:46 AM...07...02...25...EVA-3: Equipment lock preps 09:46 AM...07...03...25...EVA-3: Procedures review 11:21 AM...07...05...00...ISS daily planning conference 11:36 AM...07...05...15...NASA PAO event 12:15 PM...07...05...54...Mission status briefing on NTV 12:46 PM...07...06...25...EVA-3: Nitrogen purge procedure 01:31 PM...07...07...10...EVA-3: Airlock depress to 10.2 psi 01:51 PM...07...07...30...ISS crew sleep begins 02:21 PM...07...08...00...STS crew sleep begins 03:00 PM...07...09...39...Daily highlights reel on NTV 07:00 PM...07...12...39...Flight director's update on NTV 10:21 PM...07...16...00...Crew wakeup
9:10 AM, 4/11/10, Update: Spacewalk No. 2 ends
Astronauts Clay Anderson and Rick Mastracchio began repressurizing the space station's Quest airlock at 8:56 a.m. EDT to close out a grueling seven-hour 26-minute spacewalk, successfully installing 1,700-pound ammonia coolant tank after overcoming a sticky bolt.
The view from Clay Anderson's helmet cam as he re-entered
the Quest airlock after a grueling spacewalk. (Photo: NASA TV)
This was the 142nd spacewalk devoted to station assembly and maintenance since construction began in 1998, the sixth so far this year and the second of three planned by the shuttle Discovery's crew. Total space station EVA assembly time now stands at 887 hours and nine minutes, or about 37 days. It was the fifth spacewalk overall for both Mastracchio and Anderson, who have logged just over 32 hours of EVA time each.
7:00 AM, 4/11/10, Update: Astronauts bolt new ammonia tank in place after problems with reluctant bolt; defer other objectives
Astronauts Rick Mastracchio and Clay Anderson ran into problems bolting a 1,700-pound ammonia coolant tank into place on the space station's power truss early Sunday. Finally, after multiple attempts over an hour and a half, Anderson drove a recalcitrant bolt home to clear the problem.
"Come on, baby. Come on!" he grunted as he drove the bolt. "Get on there. Yeah, get 're done! She's on."
"Thanks, Clay. Very good job," spacewalk coordinator Dottie Metcalf-Lindenburger called from the shuttle Discovery's flight deck.
The goal of Sunday's spacewalk was to remove a depleted ammonia coolant tank from the space station's main power truss and install a replacement. The old tank was successfully removed and tethered to an equipment cart. The astronauts then began work to install the new tank.
The massive tanks use spring-loaded bolts on four corners to engage receptacles on the power truss. Mastracchio and Anderson began attempting to line the bolts and receptacles up around 5:09 a.m. But they were unable to get one bolt - No. 4 - to engage.
After trying a variety of fixes, flight controllers told them to get a hammer and attempt to "pound" that corner into place.
"We don't think releasing bolt two is going to solve anything and it would be a step backwards," called Stan Love from mission control. "What we would like Rick and Clay to try next is to use the hammer to try to pound the bolt four corner down. And we'd like them to hammer on the flat part of the assembly where two of the plungers are."
But Mastracchio and Anderson objected that a hammer likely would not work, saying they already had applied more force than that by manually shoving on the tank in a bid to get all four bolts to engage.
"OK, stand down on the hammering," agreed spacewalk coordinator Dottie Metcalf-Lindenburger.
"Yeah, we're hitting it a lot harder than we can with a hammer," Mastracchio radioed. He suggested moving a foot restraint and repositioning the astronauts to apply more downward force to the ammonia tank.
Mission control then suggested backing out the bolts that were already engaged and try again from scratch, rocking the tank and using its momentum to help drive the bolts into the receptacles.
"OK, after talking about it, we're thinking if maybe Rick got back in the APFR (articulating portable foot restraint) to provide good steadying for the tank, if you could undo bolt two and with the tank now free try to re-seat it using its momentum. We think it might help to bias the tank away from the bad plunger on bolt four.
"That might work," Mastracchio said.
"So let me make sure I understand," Anderson said. "We're basically going to go back to the original situation and just try to use the momentum to try to slam it over bolt four."
The astronauts then repositioned themselves and made another attempt to engage the reluctant bolt.
"No joy," Anderson radioed after making multiple attempts to muscle the bolt into its receptacle.
Mission control then asked the crew to detach one bolt holding the tank in place and to try again, working the tank side to side.
"Ah, you've got to be kidding me!" Anderson exclaimed as bolt four suddenly engaged.
"Did it go in?" Metcalf-Lindenburger asked.
"Yes," Anderson laughed. "You have got to be kidding me! It went in there quicker than... now what do we do?"
Using a power screw driver, Anderson drove the bolt in, switching to a higher torque setting to finish the job. The spacewalkers then worked their way around to the rest of the bolts.
Because of the time lost getting the new tank in place, flight controllers told Mastracchio and Anderson to forego connecting ammonia lines to the tank and to defer bringing no-longer-needed debris shields into the station for return to Earth. Those tasks likely will be added to the crew's third spacewalk Tuesday.
The ammonia connections were deferred because if a leak occurred and an astronaut's suits was contaminated, there would not be enough time for a "bake out" cleaning procedure.
3:55 AM, 4/11/10, Update: Depleted ammonia tank removed and temporarily stowed
Two hours into a planned 6.5-hour spacewalk, astronauts Rick Mastracchio and Clay Anderson, assisted by the space station's robot arm, have successfully removed a partially depleted 1,295-pound ammonia coolant tank and temporarily stowed it on an astronaut tool cart.
After attaching a pair of radiator servicing fixtures to the power truss, the spacewalkers will turn their attention to installing a full 1,700-pound ammonia tank carried up by the shuttle Discovery that was temporarily parked on the truss Friday.
If all goes well, the old tank will be moved to the shuttle Discovery's cargo bay during a third spacewalk Tuesday.
In orbital darkness, Rick Mastracchio and Clay Anderson secure
a depleted ammonia tank to an astronaut equipment cart. A new
tank, temporarily parked earlier, is visible to the left.
(Photo: NASA TV)
There have been no problems of any real significance during Sunday's spacewalk, although manually detaching the old tank and holding it steady so the station's robot arm could lock on proved to be a bit of a challenge.
With Mastracchio holding the massive tank in place, Anderson helped orient it so Stephanie Wilson, operating the robot arm, could lock on. But as he was trying to move out of the way, his suit apparently got hung up on some attachment fittings, imparting a slow movement to the big tank.
"OK Clay, all right, you just watch, it looks like you may be putting a couple of rates into the tank," spacewalk coordinator Dottie Metcalf-Lindenburger warned.
"Yeah, I know," Anderson said, trying to get clear of the tank. "Stand by. Gosh dog it. ... Crud! You silly beast, jimmy Christmas!"
"Clay, what's happening there?" Metcalf-Lindenburger asked.
"It's one of these pit pin lanyards," Anderson explained. "There, I'm off."
"OK, I copy, I know there's a lot of supplies over there on your left," Metcalf-Lindenburger said. "Just go slow, it's fine, there's no rush, there's plenty of sunlight for them to grapple with."
"All right, Rick, I think I'm out of your way," Anderson said a moment later.
A few minutes after that, Wilson drove the robot arm in to capture the tank.
"The SSRMS has the tank," she confirmed."
"Thank you," Mastracchio said.
Wilson and shuttle pilot James Dutton then moved the depleted ammonia tank to an astronaut equipment cart on the front side of the station's solar power truss and the spacewalkers secured it in place with six tethers.
"And Rick and Clay, Steph and Jim and Dottie, real nice job, great team work," shuttle commander Alan Poindexter radioed. "You guys are doing great. It's really awesome to see you working."
1:35 AM, 4/11/10, Update: Spacewalk No. 2 begins
Running about 45 minutes ahead of schedule, astronauts Rick Mastracchio and Clay Anderson, floating in the Quest airlock module, switched their spacesuits to battery power at 1:30 a.m. EDT Sunday to officially begin a planned six-and-a-half-hour spacewalk.
The primary goals of the excursion are to continue work to install a new ammonia coolant tank and to retrieve no-longer-needed debris shields that were stored outside the station during an earlier assembly mission.
This is the 142nd spacewalk devoted to station assembly and maintenance since construction began in 1998, the sixth so far this year and the second of three planned by Discovery's crew.
10:10 PM, 4/10/10, Update: Astronauts prep for second spacewalk
Astronauts Rick Mastracchio and Clay Anderson are gearing up for a planned 6.5-hour spacewalk early Sunday, the second of three planned by the shuttle Discovery's crew. The goals of this excursion are to install a new ammonia coolant tank on the station's power truss and to move no-longer-needed debris shielding into the station for return to Earth.
This will be the 142nd spacewalk devoted to station assembly and maintenance since construction began in 1998, the sixth so far this year and the fifth overall for both Mastracchio and Anderson.
The spacewalk is scheduled to begin at 2:16 a.m. EDT, when the astronauts switch their spacesuits to battery power. For identification, Mastracchio, call sign EV-1, will be wearing a suit with red stripes around the legs. Anderson, EV-2, will be wearing an unmarked spacesuit.
The International Space Station features two independent coolant loops that circulate ammonia through huge radiator panels to dissipate the heat generated by the lab's electrical systems. Each loop features a nitrogen pressurization system, an ammonia reservoir and internal bellows, or accumulators, that allow for the expansion and contraction of the coolant as the station moves through sunlight and orbital darkness.
"The coolant that we use is ammonia, so it gets circulated by a pump, it picks up heat from all our avionics and through a heat exchanger, picks up the heat from our internal(equipment) inside all the laboratories," said Flight Director Ed Van Cise. "That ammonia gets circulated out to our radiators and the radiators allow us to reject that heat from the ammonia out to the much colder space environment. That's how we keep everything cool."
When the truss segments housing the two ammonia tanks were launched, "the vast majority of the system was launched dry," Van Cise said. "It had nitrogen in it, we vented the nitrogen and then we had to fill the system with ammonia. So the original tanks that flew up full were depleted. If we had to, for some reason, refill the lines again due to a leak or something of that nature, we don't have enough ammonia to be able to do that.
"So to preposition ourselves for the long-term utilization of the space station, we're now replacing both sets of tanks so we have a full supply of ammonia so we can compensate if we need to. On a previous mission, we replaced the first ammonia tank and on this mission we're replacing the second."
Because of the distance between the tanks in the station's power truss and the shuttle's payload bay, the lab's robot arm must move to different work stations during the replacement procedure. As a result, three spacewalks are needed to remove a tank, install its replacement and then move the old tank to the shuttle's cargo bay for return to Earth.
"If you remember, on spacewalk number one we took the new tank, took it out of the (shuttle's) payload bay, we staged it on the mobile transporter," Van Cise said. "Last night on my shift, we took the space station's robot arm, we walked it off, if you will, so it's prepositioned to support the (second) spacewalk.
"So on this upcoming spacewalk, we're going to take the old tank out (of the truss), we're going to temporarily stow it on the CETA cart, a little cart that moves along the truss. They're going to tie it down to that cart. We'll go get that new tank, install the new tank into the truss and make all the connections. So by the end of the spacewalk, that new tank will be connected, our thermal operations officer can go verify everything is working.
"In the meantime, they will take that old tank and preposition it so that on the third spacewalk (Tuesday) it can then finally be put back into the payload bay."
Along with installing the new tank Sunday, Mastracchio and Anderson plan to retrieve no-longer-needed debris shields that have been temporarily stored outside the Quest airlock module. The shields will be brought inside and moved to the Leonardo cargo module for return to Earth.
While the spacewalk is going on Sunday, other astronauts will continue work to unload the supplies and equipment brought up in Leonardo and moving other no-longer-needed gear into the module to take its place.
Here is an updated timeline of today's activity (in EDT and mission elapsed time; includes revision F of the NASA television schedule; best viewed with fixed-width font):
EDT........DD...HH...MM...EVENT 09:21 PM...05...15...00...Crew wakeup 10:01 PM...05...15...40...EVA-1: Airlock repress/hygiene break 10:51 PM...05...16...30...EVA-1: Airlock depress to 10.2 psi 11:51 PM...05...17...30...MPLM transfers resume 04/11 12:41 AM...05...18...20...EVA-2: Spacesuit purge 12:56 AM...05...18...35...EVA-2: Spacesuit prebreathe 01:46 AM...05...19...25...EVA-2: Crew lock depressurization 02:16 AM...05...19...55...EVA-2: Spacesuits to battery power 02:21 AM...05...20...00...EVA-2: Airlock egress 02:31 AM...05...20...10...EVA-2: S1 truss ammonia tank assembly removal 03:31 AM...05...21...10...EVA-2: ATA tiedown on CETA cart 04:16 AM...05...21...55...EVA-2: P1 radiator grapple fixture beam 04:46 AM...05...22...25...EVA-2: AGB release 05:16 AM...05...22...55...EVA-2: New ATA install on S1 truss 06:01 AM...05...23...40...EVA-2/EV-1: S1 truss ATA connectors 06:16 AM...05...23...55...EVA-2/EV-2: Foot restraint relocate 06:46 AM...06...25...00...EVA-2: CETA ATA release 07:46 AM...06...01...25...EVA-2: Airlock debris shields install 08:31 AM...06...02...10...EVA-2: Cleanup and ingress 08:46 AM...06...02...25...EVA-2: Airlock repressurization 09:01 AM...06...02...40...Spacesuit servicing 11:00 AM...06...04...39...Mission status briefing on NTV 11:06 AM...06...04...45...ISS daily planning conference 01:21 PM...06...07...00...ISS crew sleep begins 01:51 PM...06...07...30...STS crew sleep begins 02:00 PM...06...07...39...Daily highlights reel on NTV 03:00 PM...06...08...39...Shuttle booster video replay 07:00 PM...06...12...39...Flight director's update on NTV 09:51 PM...06...15...30...Crew wakeup7:00 AM, 4/10/10, Update: Astronauts discuss upcoming spacewalks, space summit
Spacewalkers Rick Mastracchio and Clay Anderson, along with robot arm operator Stephanie Wilson, fielded questions from reporters early Saturday, taking a few moments to discuss the crew's upcoming spacewalks, a "space summit" next week and the 40th anniversary of Apollo 13. Here is the conversation with CBS Radio's Peter King and space consultant William Harwood:
Peter King: Morning, Stephanie Wilson, Rick Mastracchio and Clay Anderson. This is Peter King in Florida, Bill Harwood will be joining us from the Johnson Space Center. Let's start with Rick and Clay. You had a great first EVA yesterday, tomorrow morning you head out for the second of three. Just wondering what's the biggest challenge you face in tomorrow's EVA?
Rick Mastracchio: "Tomorrow's EVA, we will be installing the new ammonia tank and removing the old ammonia tank. The biggest challenge is just the integration of all the robotics and the EVA. A couple of times during tomorrow's EVA we're going to have to lift up this 1,800-pound ammonia tank while the robotic arm folks, Stephanie and Jim Dutton, come in and grapple it. It's going to require a lot of teamwork to get that to work out smoothly.
Astronauts Rick Mastracchio (left), Stephanie Wilson and Clay
Anderson field questions from reporters. (Photo: NASA TV)
Peter King: Stephanie, for the EVA and also for the late heat shield inspection, which is now going to be while you're attached to station, what are the special challenges there? Are there a lot of clearances you have to look after on both the EVA and the inspection?
Stephanie Wilson: "Always with the robotics operations clearances are a concern. Luckily, during EVA we have Clay and Rick to help us clear things. So when the (ammonia) tank gets close to structure, we're using their eyes for clearances. We wish we could have them outside also when we do this docked inspection. It is true that while we're docked, the clearances of the arm and the (sensor) boom to structure will be very tight and we don't always have cameras to get as good of a view as we would like to the station structure. But we'll do our best, we've got folks working on the ground, actually as we speak, reviewing procedures and getting all of that ready for us. So we expect it to go very well.
William Harwood: Hey guys, this is Bill Harwood at the Johnson Space Center. As you know, President Obama is visiting KSC next week to discuss the administration's new space policy. I realize it's probably career limiting for astronauts to talk politics, but this is a major sea change. Some people think it's the end of manned space flight, some think it's a bold step forward. Clay, can you share the short version of what you think about this big change that's coming?
Clay Anderson: Life is full of changes and change is hard. We know that from many different aspects of all our lives. New parents find that change is a little tough in the beginning but eventually they figure it out. That's what we'll do with NASA and the space program. I have no idea what real changes are coming. There is one side, one view, and then there's the other side and we'll just have to see how it all falls out. A lot of people get paid a lot of money to figure out this stuff and my job's to go out and perform as an astronaut and do spacewalk duty. So we'll just have to see what happens.
William Harwood: Let me ask you an operator question in that case. You're obviously a shuttle veteran and you've lived on the space station. No matter what happens, it looks like the station's going to be the only game in town for quite a while in the manned spaceflight world. How confident are you that NASA and the partners can sustain the lab complex, keep it going, without the shuttle there to support it?
Clay Anderson: The shuttle was a big workhorse, but we have a lot of new players on the block. The Automated Transfer Vehicle from the European Space Agency, the H2 transfer vehicle from the Japanese, the Progress from the Russians, and the Soyuz. We have a lot of very talented countries participating in this endeavor and right now, I don't have any reason to believe that we can't continue to do what we've been doing all along. It just remains to be seen in the future. But I think, I have a high confidence in all these international partners being able to sustain the station and do some really excellent work.
Peter King: A lot of people are wondering what the president will say when he comes to the Cape this coming week. What do you hope to hear from him?
Rick Mastracchio: Well, I hope to hear that in the future NASA will be a big part, have a large part in the human spaceflight. Obviously, NASA is meant to be a leader of the country and a leader of the world in technology and innovation and that's what it's been for many, many years. I hope that NASA will continue to be that way and I have no doubt that it will be. No matter which direction we take, I think NASA's going to be a big contributor to technologies and new ideas in manned spaceflight.
Peter King: This question is for any and all of you. You had a smoke alarm that got everybody scrambling early this morning. We know that turned out to be OK, but 40 years ago this coming week a very real emergency took place on Apollo 13. I'm just wondering your thoughts on that ... and what the Apollo 13 experience has meant to the program in the 40 years since it happened?
Stephanie Wilson: That's an excellent question and it really is a testament to teamwork. Flight crews, the mission control centers, the folks who train us and work on procedures, folks that get our vehicles ready and really know the ins and outs of the vehicles, really all have to come together in an emergency. But from every emergency, we learn something new, we update our procedures, we update our response times and it really is an opportunity to get to be more familiar with things but also to come together and work better together as a team.
Peter King: For Clay and Rick, one quick question. You have just one day off between your EVAs. We know how hard it is physically. Is one day's rest really enough to recoup your energy and go back and do it again?
Clay Anderson: "I've played a lot of sports in my life and there were a lot of days when we had double headers and a lot of days we play ed basketball games in back to back days. I think we're very well prepared. We're in pretty good shape for old men and I think we'll be ready to rock and roll.
Peter King: Thank you so much for spending time with us this morning.
10:15 PM, 4/9/10, Update: Shuttle-to-station cargo transfers on tap
The Discovery astronauts and their space station colleagues face a full "day" of work overnight Friday and early Saturday to transfer supplies and equipment from the Leonardo cargo module to the International Space Station.
"Everybody's going to be doing quite a bit of transfer tomorrow (Saturday)," said space station Flight Director Ed Van Cise. "We're going to continue to work on moving some of those big experiment racks out of the logistics module. ... At the end of the day, we're also getting ready to go do our second spacewalk (Sunday)."
Spacewalkers Rick Mastracchio and Clay Anderson, along with robot arm operator Stephanie Wilson, will participate in interviews early Saturday with CBS Radio and other media clients. An educational event with shuttle flight engineer Dottie Metcalf-Lindenburger, a former high school teacher, is planned for 10:36 a.m., followed by a mission status briefing. All three events will be carried live on NASA television.
The Italian-built Leonardo module carried aloft aboard Discovery was attached to the forward Harmony module's Earth-facing port early Wednesday. The module was loaded with more than 17,000 pounds of supplies, science equipment and other hardware needed aboard the space station.
Five of seven science and equipment racks were moved into the space station overnight Thursday and Friday. Early Saturday, the astronauts plan to move another experiment rack into the station - Express Rack 7 - and a darkroom-like enclosure that will fit around the Destiny lab module's porthole to improve Earth-observation photography and research.
"We are, overall, about 18 percent done with our transfer, yesterday being our first really big transfer day," Van Cise said earlier Friday. "We are about 68 percent done with transferring everything out of the (shuttle's) middeck and getting things back, ready for return, things that are going to come home in the middeck. We're not quite as far along in the pressurized logistics module yet. ... So technically, we're about 5 percent done (with MPLM transfers).
"Yesterday, we spent a lot of time moving a few of the very large items. We transferredÊfive different racks out of the logistics module into the space station. So 5 percent may seem like a small number percentage wise, but we transferred a bunch of big items."
With their crewmates focusing on transfer work, Anderson and Mastracchio, meanwhile, will prepare tools and equipment for use during a second planned spacewalk early Sunday to install a new ammonia coolant tank in the space station's main power truss. The 1,700-pound tank was moved from Discovery's cargo bay to a temporary storage point on the station during their first spacewalk early Friday. During a third spacewalk Tuesday, a depleted ammonia tank will be moved to Discovery for return to Earth.
NASA's Mission Management Team decided Friday to extend Discovery's mission by one day to give the crew more time to carry out a final heat shield inspection while docked to the space station. Landing is now targeted for 8:54 a.m. EDT Monday, April 19. An updated flight plan will be posted as soon as the information becomes available.
Here is an updated timeline of today's activity (in EDT and mission elapsed time; includes revision X of the NASA television schedule; best viewed with fixed-width font):
EDT........DD...HH...MM...EVENT 04/09 09:21 PM...04...15...00...Crew wakeup 10:46 PM...04...16...25...ISS daily planning conference 04/10 12:21 AM...04...18...00...MPLM cargo module transfers resume 12:26 AM...04...18...05...Window Observation Research Facility transfer 01:56 AM...04...19...35...Zero-G storage rack transfer 02:21 AM...04...20...00...Zero-G storage rack deploy 02:51 AM...04...20...30...Express Rack 7 transfer 03:51 AM...04...21...30...Crew meals begin 04:16 AM...04...21...55...EVA-2: SSRMS maneuver 04:51 AM...04...22...30...ISP install 05:56 AM...04...23...35...Media interviews 06:16 AM...04...23...55...EVA-2: Tools configured 06:51 AM...05...30...00...ISP install 07:21 AM...05...01...00...MPLM pivot install 07:36 AM...05...01...15...EVA-2: Equipment lock preps 09:16 AM...05...02...55...EVA-2: Procedures review 10:36 AM...05...04...15...PAO educational event 11:00 AM...05...04...39...Mission status briefing on NTV 11:11 AM...05...04...50...ISS evening planning conference 11:46 AM...05...05...25...EVA-2: Mask pre-breathe/nitrogen purge 12:31 PM...05...06...10...EVA-2: Airlock depress to 10.2 psi 12:51 PM...05...06...30...ISS crew sleep begins 01:21 PM...05...07...00...STS crew sleep begins 02:00 PM...05...07...39...Daily highlights reel on NTV 06:30 PM...05...12...09...Flight director's update on NTV 09:21 PM...05...15...00...Crew wakeup
7:30 PM, 4/9/10, Update: Shuttle mission extended one day
The shuttle Discovery's mission to the International Space Station has been extended one day to give the astronauts more time to conduct a final heat shield inspection while docked to the lab complex. Landing is now expected on April 19.
The so-called late inspection normally is carried out immediately after undocking. Video and laser scan data is downlinked in realtime using the shuttle's Ku-band antenna system. But Discovery's Ku antenna failed to activate after launch and the astronauts were forced to use the space station's communications system to downlink inspection data collected the day after launch.
Likewise, the astronauts will use the station again to downlink the late inspection data.
"The Mission Management Team elected to add a day to the mission," said space station Flight Director Ed Van Cise. "The reason for that goes all the way to ... when the space shuttle Ku-band system was determined not to be operating. We have flight rules that say if the Ku-band is not operational, we need to an inspection of the orbiter while it is still docked to the space station. We call it late inspection.
"When the Ku-band system is working, they will actually do that late inspection after they have undocked and that will clear the thermal protection system for entry. Since we need to use the ISS Ku-band system to downlink all those files and the video, obviously we need to do that before they have undocked. So we needed to have the time to perform those inspections.
"We could either do that with our 13-day mission at the expense of some of the other mission objectives we already had planned, including all of this transfer, or we could add a day to the mission," V an Cise said. "And since we were carrying some contingency time we could add that extra day and make it a 14-day mission so that we could spend an extra day to go do that late inspection while we are docked."
One other post-Columbia late inspection was carried out prior to a shuttle's undocking but in that case, the crew was leaving the shuttle's heat shield inspection boom behind on the space station for use by the next visiting shuttle crew.
8:05 AM, 4/9/10, Update: Spacewalk No. 1 ends
Astronauts Rick Mastracchio and Clay Anderson wrapped up a successful six-hour 27-minute spacewalk early Friday, repressurizing the space station's Quest airlock module at 7:58 a.m. EDT to bring the excursion to a close.
The astronauts released a 1,700-pound ammonia coolant tank in the shuttle Discovery's cargo bay so it could be moved to the space station and installed a rate gyro assembly, a device that helps determine the lab's orientation in space. They also carried out a variety of get-ahead tasks to save time for future spacewalkers.
There were no significant problems and the astronauts accomplished all of their major objectives.
Astronauts Rick Mastracchio and Clay Anderson return to
the space station's Quest airlock module. (Photo: NASA TV)
This was the 141st spacewalk devoted to station assembly and maintenance since construction began in 1998, the fifth so far this year and the first of three planned by Discovery's crew. Total station EVA time now stands at 879 hours and 43 minutes.
7:00 AM, 4/9/10, Update: Rate gyro assembly installed; astronauts work on get-ahead tasks
Astronaut Rick Mastracchio replaced a rate gyro assembly in the International Space Station's main power truss Friday to accomplish the second major objective of the Discovery crew's first spacewalk. Mastracchio and Clay Anderson are in the process of carrying out a few get ahead tasks before wrapping up the excursion. There have been no major problems and the astronauts are roughly on schedule.
Clay Anderson and Rick Mastracchio attach a handling fixture to a new
ammonia coolant tank. (Photo: NASA TV)
The shuttle-station complex passes 220 miles above the
Nile River. (Photo: NASA TV)
Rick Mastracchio completes installation of a new rate
gyro assembly. (Photo: NASA TV)
4:15 AM, 4/9/10, Update: New ammonia tank removed from shuttle
Spacewalker Clay Anderson resorted to a pry bar early Friday to free a 1,700-pound ammonia coolant tank from its mount in the shuttle Discovery's cargo bay.
Then, with Anderson and Rick Mastracchio manually holding the massive tank, the space station's robot arm latched on and began moving it to a temporary mounting point on the lab's main power truss.
The space station's robot arm moves the new ammonia tank
assembly from the shuttle Discovery to the station. (Photo: NASA TV)
"Clay, good job, man," Mastracchio radioed.
"Yeah, you too," Anderson said.
"Yeah Clay, you did a great job holding that tank steady," someone said.
"I totally agree," said spacewalk coordinator Dottie Metcalf-Lindenburger.
"That's what they say," Anderson laughed. "'Git her done.'"
While Anderson cleaned up the payload bay worksite, Mastracchio headed to the Japanese Kibo module to retrieve an experiment package. Both spacewalkers plan to meet the robot arm near the station's airlock to attach a grapple fixture to the ammonia tank.
The arm, driven by Stephanie Wilson and shuttle pilot James Dutton, then will move the tank to a temporary mounting point on the space crane's mobile base station where it will remain until its actual installation during the crew's second spacewalk.
Anderson and Mastracchio, meanwhile, will work to replace a rate gyro assembly, a device that helps the station determine its orientation in space.
ONce that work is done, the spacewalkers will focus on a few get-ahead tasks before calling it a day and heading back to the airlock.
1:40 AM, 4/9/10, Update: Spacewalk No. 1 begins
Floating in the space station's Quest airlock module, astronauts Richard Mastracchio and Clayton Anderson switched their spacesuits to battery power at 1:31 a.m. EDT Friday to officially kick off a planned six-and-a-half-hour spacewalk.
"Gentlemen, the weather's beautiful outside, it's a great day for an EVA," pilot James Dutton radioed from outside the airlock. "Have a great time, guys."
Astronaut Rick Mastracchio exits the Quest airlock to
begin a planned 6.5-hour spacewalk. (Photo: NASA TV)
This is the 141st EVA devoted to station assembly and maintenance since construction began in 1998, the fifth so far this year and the first of three planned by the Discovery astronauts. It is the fourth spacewalk overall for both Mastracchio and Anderson, who carried out an EVA together in August 2007.
"And Rick and Clay, it's been an absolute pleasure watching you guys in the pool," said Dottie Metcalf-Lindenburger, the spacewalk coordinator. "And today, I'm looking forward to seeing you do EVA-1 as we practiced. Remember, space is like chocolate. Go get a big bite."
The primary goal of today's spacewalk is to move a new ammonia coolant tank from the shuttle Discovery's cargo bay to a temporary storage location on the space station's power truss and to prepare a depleted tank for removal.
The astronauts also will replace a rate gyro assembly, a device that helps the station's computers determine the lab's orientation in space, along with performing a few "get-ahead" tasks for upcoming assembly work.
8:15 PM, 4/8/10, Update: Astronauts set for first spacewalk
Astronauts Rick Mastracchio and Clay Anderson are set for a planned six-and-a-half-hour spacewalk Friday, the first of three excursions required to install a 1,700-pound ammonia coolant tank on the International Space Station's solar power truss.
Mastracchio and Anderson spent 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. Wakeup is scheduled for 8:51 p.m. EDT and if all goes well, the astronauts will switch their spacesuits to battery power at 1:41 a.m. EDT Friday to officially begin the 141st spacewalk devoted to space station assembly and maintenance.
For identification, Mastracchio, call sign EV-1, will be wearing a suit with red stripes around the legs. Anderson, EV-2, will be wearing an unmarked spacesuit.
The International Space Station features two independent coolant loops that circulate ammonia through huge radiator panels to dissipate the heat generated by the lab's electrical systems. Each loop features a nitrogen pressurization system and an ammonia reservoir that must be periodically replaced.
"It's like Freon in your air conditioner at home, but we use ammonia on the outside of the station," Anderson said. "So we have a huge tank. ItÕs about eighteen hundred pounds. It's probably the size of a double refrigerator-freezer component. There are actually two, one on the right and one on the left. The one on the left has recently been changed out by another shuttle crew. So we're going to change the one on the right."
Mastracchio said the biggest challenge is the coordination required to swap out the massive components.
"The real challenge here is this ammonia tank that we're moving is taking three EVAs, or part of three EVAs, to get it done," he said. "Our first EVA, we'll remove the new ammonia tank from the shuttle and get it onto the station (where) we'll temp stow it. The second EVA, we'll actually swap the two ammonia tanks, the new one for the old one and then on the third EVA, we'll be moving the old tank from the space station into the space shuttle's payload bay for return."
During Friday's spacewalk, Anderson and Mastracchio first will disconnect ammonia and nitrogen pressurization lines from the old tank, then move to the shuttle's cargo bay where they will detach the new ammonia tank assembly from its mount and hand it off to the station's robot arm.
Stephanie Wilson and shuttle pilot James Dutton, operating the space station's robot arm, will move the new ATA to a temporary mounting point on the crane's mobile base. While that is going on, the spacewalkers will install a replacement rate gyro assembly, a device that helps the station's computers determine the lab's orientation in space.
"During each of the EVAS, we have to hold the ATA, this ammonia tank, up over our heads," Mastracchio said. "Clay's going to do it on EVA-1 then I do it on EVA-2. We're going to be holding this tank over our heads, trying to control it while Jim and Stephanie come in and grapple it. So I'm a little concerned about trying to have the stability to hold that tank nice and firm and steady ... so they can come in and grapple it."
Anderson and Mastracchio originally planned to venture out to the far left end of the station's main power truss to loosen bolts holding an aging set of solar array batteries in place to save time when the batteries are replaced during the next shuttle mission.
But mission managers opted to delete the battery work after an analysis showed the possibility of an electric shock hazard involving the mini work stations attached to the astronauts' suits that hold tools and other gear.
Devices called plasma contactor units operate during space station EVAs to prevent dangerous charge buildups. But at the far ends of the power truss, depending on the station's orientation with respect to Earth's magnetic field and a variety of other factors, a shock hazard remains a possibility.
As a result, the battery work was deleted from Friday's spacewalk. Long term, the astronauts who will remove the batteries during the next shuttle mission will use equipment that is better insulated to eliminate the threat.
While Anderson and Mastracchio are working outside the station, the astronauts inside the lab will be working to unload the Leonardo multi-purpose logistics module. Among the items scheduled for transfer during the spacewalk are an experiment sample freezer, known by the acronym MELFI, a muscle loss experiment and a new crew cabin, the fourth and final U.S. cabin to be moved to the station.
NASA's original plan was to equip the sleep station with a curtain-like liner to turn it into a bathing and hygiene cabinet.
"It's a space shower," said Kirk Shireman, deputy manager of the space station program at the Johnson Space Center. "We don't really take showers on board the ISS, but people need to bathe and shampoo their hair and because it can release free water, we like to do it in a place that won't allow the water to float and get into avionics, electrical equipment, that can cause damage.
"So we actually put a liner in there. It's not as simple as you would think. It's not just a shower curtain, it's a little more complicated than that. But it's a station with privacy where the crew members can go and clean up. A very important thing from a health standpoint and also a psychological standpoint."
But with the arrival of the Soyuz TMA-18 spacecraft last weekend, the Expedition 23 crew includes three Russians. The Russian segment of the station only has two crew sleep stations and a third will not be available until 2012 when a new Russian lab module is launched. NASA may let the Russians use the new U.S. crew cabin as needed until then and instead use the toilet compartment in the Tranquility module as a hygiene station.
Here is an updated timeline of today's activity (in EDT and mission elapsed time; includes revision C of the NASA television schedule; best viewed with fixed-width font):
EDT........DD...HH...MM...EVENT 04/08 08:51 PM...03...14...30...Crew wakeup 09:26 PM...03...15...05...EVA-1: Airlock repress/hygiene break 10:16 PM...03...15...55...EVA-1: Airlock depress to 10.2 psi 11:31 PM...03...17...10...MPLM transfers 04/09 12:06 AM...03...17...45...EVA-1: Spacesuit purge 12:21 AM...03...18...00...EVA-1: Spacesuit prebreathe 01:11 AM...03...18...50...EVA-1: Crew lock depressurization 01:41 AM...03...19...20...ZSR transfer 01:41 AM...03...19...20...EVA-1: Spacesuits to battery power 01:56 AM...03...19...35...EVA-1/EV-1: FBG retrieve 01:56 AM...03...19...35...EVA-1/EV-2: S1 ATA FQD release 02:06 AM...03...19...45...ZSR deploy 02:26 AM...03...20...05...EVA-1/EV-1: Payload bay ATA release preps 02:41 AM...03...20...20...EVA-1/EV-2: Payload bay ATA preps 03:11 AM...03...20...50...EVA-1: ATA release and handoff 03:36 AM...03...21...15...MELFI transfer 03:56 AM...03...21...35...EVA-1/EV-1: JEM seed retrieval 03:56 AM...03...21...35...EVA-1/EV-2: Payload bay cleanup 04:36 AM...03...22...15...CQ2 transfer 04:41 AM...03...22...20...EVA-1: ABG retrieve and install 05:26 AM...03...23...05...EVA-1: S0 RGA R&R 05:56 AM...03...23...35...EVA-1/EV-2: P1 FHRC clamp release 06:41 AM...04...20...00...EVA-1/EV-1: WIF EXT RLCT 07:11 AM...04...50...00...EVA-1/EV-2: Get aheads 07:41 AM...04...01...20...EVA-1: Cleanup 07:56 AM...04...01...35...EVA-1: Airlock ingress 08:06 AM...04...01...45...MARES transfer 08:11 AM...04...01...50...25...EVA-1: Airlock repressurization 08:26 AM...04...02...05...Post-EVA servicing 08:56 AM...04...02...35...WORF preps 10:21 AM...04...04...00...ISS crew sleep begins 10:30 AM...04...04...09...Mission status briefing on NTV 12:51 PM...04...06...30...ISS daily planning conference 01:21 PM...04...07...00...STS crew sleep begins 02:00 PM...04...07...39...Daily highlights reel on NTV 06:30 PM...04...12...09...Flight director's update on NTV 09:21 PM...04...15...00...Crew wakeup
01:05 AM, 4/8/10, Update: Leonardo cargo module attached to space station (UPDATED at 3:40 AM with news briefing)
Astronauts Stephanie Wilson and Naoko Yamazaki, operating the International Space Station's robot arm, pulled a 27,274-pound cargo module from the shuttle Discovery's payload bay late Wednesday and attached it to the lab's Harmony module early Thursday.
"We've had a good day on ISS so far," Flight Director Courtenay McMillan told reporters. "We got the MPLM (multi-purpose logistics module), Leonardo, berthed to ISS. Stephanie, Naoko and Soichi (Noguchi) all did a great job with the SSRMS (robot arm) and the berthing mechanism, everything went flawlessly."
If all goes well, the crew will open the module later this morning to begin the long process of unloading equipment and supplies, including a crew sleep station, experiment gear, a freezer and a darkroom-like enclosure that will enhance Earth observation photography.
The Leonardo cargo module, loaded with more than 17,000 pounds
of equipment and supplies, attached to the Harmony module. (Photo: NASA TV)
Another view of the Leonardo module. (Photo: NASA TV)
Early Thursday, engineers were in the process of wrapping up work to downlink massive digital video files from a heat shield inspection the shuttle crew carried out Tuesday. The post-launch failure of Discovery's Ku-band antenna system forced the astronauts to store the data on board for downlink after docking using the space station's Ku system.
"ISS systems are all performing very well and are in a good configuration to support the rest of the mission objectives," McMillan said. "We are continuing to work around the Ku problem on Discovery. We are still in the process of getting the video downlinked from the laptops. ... We're still talking about the full impacts of this issue for the rest of the mission."
The Ku failure will force Discovery's crew to carry out a final "late" heat shield inspection before the orbiter undocks from the station instead of just after, which is the usual practice. Flight controllers are discussing a variety of options, including trying to shoe-horn the inspection into the crew's existing flight plan or extending the mission to provide more time.
"We are talking about possibly extending, we are talking about deferring mission content, everything is on the table at this point," McMillan said.
In the near term, the focus is on starting work to unload the Leonardo module and preparing for the mission's first spacewalk early Friday. Clay Anderson and Rick Mastracchio spent part of their day Wednesday and early Thursday preparing their spacesuits and the tools they will use to replace a massive ammonia coolant tank on the station's main power truss.
Another objective is to replace a rate gyro unit, a device that helps the station's computers determine the lab's orientation in space. The new rate gyro unit was carried up inside the Leonardo module.
Leonardo was attached to the forward Harmony module's Earth-facing port just "above" Discovery's cargo bay. Motorized bolts in the common berthing mechanism were driven home in two stages, securing the module in place by 12:24 a.m. EDT.
Discovery's mission is the final shuttle flight to carry one of the Italian-built cargo modules to and from the space station. Leonardo will make a final trip to the station on the last shuttle flight later this year, but it will be modified with additional micrometeoroid shielding to remain behind as a sort of long-term storage closet when the last orbiter departs.
10:35 PM, 4/7/10, Update: Starboard wing heat shield cleared; astronauts press ahead with cargo module installation on space station
Imagery analysts completed an assessment of the shuttle Discovery's right wing heat shield components late Wednesday and cleared the astronauts to press ahead with work to move a cargo module from the shuttle's payload bay to the International Space Station as planned.
Operating the station's robot arm from a work station in the U.S. Destiny lab module, Stephanie Wilson and Japanese astronaut Naoko Yamazaki latched onto the Leonardo multi-purpose logistics module, or MPLM, around 10:30 p.m. EDT.
The station's robot arm moves in to grapple the Leonardo cargo
module. The shuttle Discovery's robot arm, with an attached
heat shield inspection boom, extends to the right in the background.
(Photo: NASA TV)
After carefully pulling the 27,274-pound module from Discovery's cargo bay, Wilson and Yamazaki will maneuver it into position for attachment to the station's Harmony module just after midnight.
Discovery's right wing had to be given a clean bill of health before the module's move because of robot arm clearance issues in case any problems were discovered that required a more detailed, "focused" inspection using a 50-foot-long sensor boom attached to the shuttle's robot arm.
With the Leonardo module attached to the station, clearance issues would have prevented an additional right-wing inspection. But as it turned out, no such inspection will be needed.
NASA's Damage Assessment Team is still plowing through data from an inspection of the shuttle's nose cap and wing leading edge panels carried out Tuesday and a photo-survey of tiles on the shuttle's belly that was conducted during the shuttle's final approach to the station early Wednesday.
6:40 PM, 4/7/10, Update: Heat shield analysis slowed by station network traffic; cargo module set for move to lab
Traffic on the International Space Station's local area network has slowed downlink of multi-gigabyte heat shield inspection files, NASA officials said Wednesday. But no major problems have been seen so far as analysts prioritize their work to clear the shuttle Discovery's right wing first, allowing the astronauts to attach a massive cargo module to the space station overnight Wednesday.
The Leonardo multi-purpose logistics module, or MPLM, is loaded with more than 17,000 pounds of science gear, equipment and supplies for the International Space Station, including a new crew sleep station, an experiment sample freezer and a darkroom-like enclosure to improve Earth-observation photography from a lab window.
The shuttle Discovery, docked to the space station,
with the Leonardo cargo module in the payload bay. (Photo: NASA TV)
Mounted in the back of Discovery's cargo bay, the MPLM is scheduled to be attached to the station's Unity module just after midnight.
But once the module is in place, the 50-foot-long robot arm extension that would be needed to re-examine any areas of concern on the shuttle's right wing would not be able to get in the proper position if a problem was found later that required a "focused" inspection.
"The items of greatest priority and interest to us are those associated with the starboard wing," said LeRoy Cain, chairman of NASA's Mission Management Team. "We want to clear the starboard wing from any focused inspection requirements as soon as we can because we do have some (robot arm) interference once we take the MPLM out and put it on the station. So, that work is ongoing and we anticipate that we'll be able to press ahead with the MPLM work when the crew gets up tonight."
Detailed flight day two inspections of the shuttle's reinforced carbon carbon nose cap and wing leading edge panels, which experience the most extreme heating during re-entry, normally are transmitted to the ground in real time. But because the shuttle's Ku-band antenna is out of action due to a post-launch malfunction, the astronauts were forced to convert the videos to digital files for downlink through the station's Ku-band system.
Six such 7.2-gigabyte files were generated but as of 6 p.m. Wednesday, only the first two had made it down to the ground. One more is needed to clear the right wing before the MPLM can be installed.
"We were targeting to have all of the starboard wing data to the ground by 11 o'clock and some of the rest of the data in addition to that," Cain said. "We did not have it all to the ground by then. Part of the challenge we had is the rate of the data coming down was varying somewhat and we think it had to do with the amount of traffic on the local area network between the shuttle and the station during that time period.
"Right after we got docked and got the hatches open and (brought) all those systems up, there's a number of other activities that have to go on. ... What we found is, once the crew went to sleep, the rate increased pretty significantly because there was a lot less traffic on the LAN."
Cain said additional imagery confirmed the loss of part of a heat shield tile on Discovery's rudder-speedbrake. Analysts also have noted a small amount of surface damage on a tile near one of the propellant feedline doors on the shuttle's belly. But he said neither issue was expected to cause any problems.
Discovery's vertical tail fin, showing the location of
a damaged heat shield tile. (Photo: NASA)
"All in all, Discovery's doing extremely well, the crew on board is doing very, very well and they're ready to press on with the flight plan," Cain said. "Of everything we've looked at so far, we have no concerns at all."
Here is an updated timeline of today's activity (in EDT and mission elapsed time; includes revision B of the NASA television schedule; best viewed with fixed-width font):
EDT........DD...HH...MM...EVENT 04/07 08:21 PM...02...14...00...Crew wakeup 10:01 PM...02...15...40...Russian PAO event 10:21 PM...02...16...00...Station arm (SSRMS) grapples MPLM 10:51 PM...02...16...30...SSRMS unberths MPLM 04/08 12:11 AM...02...17...50...SSRMS installs MPLM 12:36 AM...02...18...15...MPLM first stage bolts 12:56 AM...02...18...35...MPLM second stage bolts 01:11 AM...02...18...50...EVA-1: Equipment lock preps 02:00 AM...02...19...39...Mission status briefing on NTV 02:16 AM...02...19...55...SSRMS ungrapples MPLM 02:46 AM...02...20...25...Crew meals begin 03:01 AM...02...20...40...MPLM vestibule pressurization 03:46 AM...02...21...25...Middeck transfers 04:16 AM...02...21...55...MPLM vestibule config for ingress 05:46 AM...02...23...25...MPLM activation (part 1) 07:41 AM...03...01...20...MPLM activation (part 2) 08:01 AM...03...01...40...MPLM ingress 08:16 AM...03...01...55...News media interviews 08:36 AM...03...02...15...EVA-1: Procedures review 09:26 AM...03...03...05...ISS daily planning conference 11:16 AM...03...04...55...EVA-1: Mask pre-breathe 12:01 PM...03...05...40...EVA-1: Airlock depress to 10.2 psi 12:21 PM...03...06...00...ISS crew sleep begins 12:51 PM...03...06...30...STS crew sleep begins 01:00 PM...03...06...39...Daily video highlights reel on NTV 04:00 PM...03...09...39...Post-MMT briefing on NTV 06:00 PM...03...11...39...Flight director update on NTV 08:51 PM...03...14...30...Crew wakeup
4:00 AM, 4/7/10, Update: Shuttle docks with space station (UPDATED at 5:30 AM with hatch opening; updated at 7:30 a.m. with news briefing)
Commander Alan Poindexter, manually flying Discovery from the shuttle's aft flight deck, guided the spaceplane to a precision docking with the International Space Station early Wednesday after performing a flawless, "radar failed" rendezvous.
Approaching from directly in front of the space station, Discovery's payload bay docking mechanism engaged its counterpart on the front end of the forward Harmony module at 3:44 a.m. EDT as the two spacecraft sailed 220 miles above the Caribbean at 5 miles per second.
"Houston and station, capture confirmed," pilot James Dutton radioed.
"Discovery, arriving," station flight engineer Soichi Noguchi called out, ringing the ship's bell in the Harmony module.
Discovery and the space station move into sunlight over
the Atlantic Ocean. (Photo: NASA TV)
(Photo: NASA TV)
It took about one orbit to complete leak checks ensuring a tight seal between the shuttle and the space station, which together mass 1,043,000 pounds.
Hatches were opened at 5:11 a.m. and the station's six-member crew - Noguchi, Expedition 23 commander Oleg Kotov, Alexander Skvortsov, Mikhail Kornienko, Timothy Creamer, Tracy Caldwell Dyson and Soichi Noguchi - welcomed the shuttle's seven astronauts aboard.
Poindexter, Dutton, flight engineer Dorothy Metcalf-Lindenburger, Stephanie Wilson, Japanese astronaut Naoko Yamazaki and spacewalkers Richard Mastracchio and Clayton Anderson floated into the Harmony module to smiles, hugs and handshakes.
The combined 13-member shuttle-station crew is the first to boast four women and the first to include two Japanese astronauts.
The station crew, in red shirts, welcomes the Discovery
astronauts aboard. (Photo: NASA TV)
Station commander Oleg Kotov leads the shuttle crew
through the Destiny laboratory module during an initial safety briefing.
(Photo: NASA TV)
The terminal phase of the rendezvous began at 1:06 a.m. with a rocket firing to close the final 9.2 miles between the shuttle and the station. Poindexter maneuvered Discovery to a point 600 feet directly below the lab complex and then performed a slow back-flip maneuver to expose the ship's heat shield to the station.
The shuttle passes above Southeast Asia during the
rendezvous pitch maneuver. (Photo: NASA TV)
While the shuttle's Ku-band antenna/radar system was out of action because of an earlier malfunction, TV from the station provided a spectacular bird's eye view of the dramatic maneuver as Discovery passed high above southeast Asia.
Kotov and Creamer snapped 364 pictures using digital cameras equipped with 400-mm and 800-mm lenses to document the condition of the protective tiles on the shuttle's belly. The photos will be downlinked to Houston for a detailed analysis.
Shuttle Discovery approaches the space station. (Photo: NASA TV)
The station's view of Discovery as the pitch maneuver
began. (Photo: NASA TV)
The view of the space station through a camera
mounted in the shuttle's docking port. (Photo: NASA TV)
The shuttle Discovery's heat shield. (Photo: NASA TV)
The pitch maneuver concludes high above Indonesia. (Photo: NASA TV)
A telemetry-driven display in mission control showing
the relative positions of Discovery and the space station
during final approach. (Photo: NASA TV)
After the rendezvous pitch maneuver was complete, Poindexter guided Discovery up to a point about 300 feet directly in front of the space station, with the shuttle's nose pointed toward deep space and its open payload bay facing pressurized mating adaptor No. 2 on the front end of Harmony. From there, he flew the shuttle to a problem-free, on-time docking.
"It was a great day in space," said Flight Director Richard Jones. "We got successfully docked to the International Space Station and we're off to the races with respect to the rest of the docked mission. ... The 'radar-failed' (rendezvous) procedures went very well, the crew flew the rendezvous profile flawlessly and (they) made it look easy."
As soon as hatches were opened between Discovery and the station, Wilson handed off a computer hard drive loaded with stored imagery collected during an extensive inspection of the shuttle's nose cap and wing leading edge panels that was carried out Tuesday.
Because of the Ku-band antenna problems, the data could not be downlinked in real time. But using the station's Ku-band communications system, engineers expect to get all the imagery down to the ground by noon.
"The data collection process with respect to getting all the imagery down has started," Jones said. "Once the hatches were opened, we gave the ISS crew the flight day two inspection data that we had collected and they were starting to downlink that as I was walking over."
Jones described Discovery's rendezvous pitch maneuver as "just a beautiful thing to see, it's almost poetry."
"It looks like the vehicle seems to be, in general, in great health," he said. "We'll obviously let the experts look at the detailed imagery and confirm that. But things seem to be going very well."
Overnight Wednesday, the astronauts plan to move a cargo module, loaded with more than 17,000 pounds of supplies and equipment, from Discovery's payload bay to the space station.The first of three spacewalks to replace an ammonia coolant tank on the station's solar power truss is planned for early Friday.
1:30 AM, 4/7/10, Update: Shuttle Discovery closes in on space station
The shuttle Discovery closed in on the International Space Station early Wednesday, on course for a docking at 3:44 a.m. EDT.
Trailing the station by about nine miles, commander Alan Poindexter and pilot James Dutton fired the shuttle's left-side orbital maneuvering system rocket for 10 seconds at 1:06 a.m., changing the ship's velocity by 5.3 miles per hour to begin the final stage of the rendezvous.
The astronauts attempted to activate Discovery's Ku-band antenna system at 10:02 p.m., but as expected, it failed a self test. At 12:25 a.m., they attempted to lock onto the space station in radar mode but again, the system failed to operate.
The astronauts are proceeding as planned using alternate sensors to update the shuttle's navigation system.
6:50 PM, 4/6/10, Update: Astronauts prepared for no-radar station docking early Wednesday; MMT assesses tail fin debris
The shuttle Discovery's crew will attempt to activate the ship's suspect Ku-band radar during the final stages of rendezvous with the International Space Station early Wednesday. But if it doesn't work - and engineers don't believe it will - the astronauts will use other sensors to update the shuttle's navigation systems.
"We will execute the rendezvous and docking operations per the crew's radar-failed procedures," said LeRoy Cain, chairman of NASA's Mission Management Team. "Those procedures ... are practiced and trained as part of their normal training template."
Other than the post-launch loss of the shuttle's Ku-band communications system due to an unknown failure, Cain said Discovery appeared to come through its climb to space Monday in generally good condition. But engineers are studying photographs that appear to show a tile, or some similar-sized object, separating from the left side of the shuttle's vertical tail fin 42.2 seconds after liftoff as the ship was accelerating through Mach 1.
Cain wouldn't speculate on what the object might have been, although the imagery suggests it likely was a heat shield tile from the left side of the rudder-speedbrake's trailing edge.
Before-and-after pictures showing presumed debris separating
from the shuttle Discovery's vertical tail fin 42 seconds
after launch. (Photo: NASA)
"Preliminarily, I don't believe this will be any impact to us," he said. "Those tiles are in place primarily for ascent heating, the thermal environment back there with the engines running. For entry, the speedbrake is, of course, clamped closed like it is for ascent through the entire max heating portion of the entry profile and it's in the aerodynamic shadow during that entire time. Then the speedbrake opens at Mach 10.
"This is going to turn out to be a non issue for us, is what I expect," he said. "But we want the team to go off and do their normal, rigorous analysis and assessment of it."
The only other issue of any significance is the failure of Discovery's Ku-band dish antenna, used to send and receive data, commands, voice traffic and video, following launch Monday. While the antenna can track NASA's communications satellites, the two electronic subsystems that transmit and receive data appear to have suffered some sort of common failure.
One of those subsystems turns the antenna into a radar for use during rendezvous operations. The astronauts have not yet attempted to activate the radar subsystem but given the antenna's other problems, engineers are not optimistic.
But Cain said the presumed loss of the Ku in radar mode will not have a major impact on the crew's ability to rendezvous with the space station.
"We have a whole suite of navigation and rendezvous sensors that we use normally in addition to the Ku radar," he said. "In this case, we'll use those exclusively, to include the star trackers that we use for navigation, the handheld lasers as well as the trajectory control system, or TCS. So all of those systems are available and we don't anticipate any issues whatsoever with performing the radar-failed procedures for the rendezvous."
Trailing the space station by about 9.2 miles, commander Alan Poindexter and pilot James Dutton will begin the terminal phase of the rendezvous procedure at 1:06 a.m. EDT Wednesday with a critical rocket firing. As with all post-Columbia station flights, Poindexter will position the shuttle directly below the station and then perform a back-flip maneuver, starting around 2:43 a.m., to expose the ship's belly to the station.
Expedition 23 commander Oleg Kotov and flight engineer Timothy Creamer, using digital cameras with 400-mm and 800-mm lenses, will photograph the shuttle's heat shield from the station and downlink the images to mission control for analysis.
Poindexter then will guide Discovery to a point about 300 feet directly in front of the station before moving in for a docking at the lab's forward port around 3:44 a.m.
One of the first items on the agenda will be to connect to the station's wireless computer network so the shuttle crew can downlink about 40 gigabytes of data collected during an inspection of Discovery's nose cap and wing leading edge panels early Tuesday. That data normally is downlinked in realtime, but the failure of the Ku-band antenna has forced the crew to rely on the station's communications system.
"All of that data we've loaded onto one of the computers on board the shuttle and once we get docked, we'll transfer that data to the station laptop computer system and we'll do that via the wireless network we normally have configured for these shuttle-station docked missions," Cain said.
"That data will all be on the ground by about 11 o'clock local time tomorrow. Then the Damage Assessment Team will be able to review all that data as they normally do and they'll be able to give us a good idea, by the time we get to the MMT tomorrow, very preliminarily, if we have anything to be concerned about."
Here is an updated timeline of today's activity (in EDT and mission elapsed time; includes revision A of the NASA television schedule):
EDT........DD...HH...MM...SS...EVENT 04/06 08:21 PM...01...14...00...00...STS/ISS crew wakeup (begin flight day 3) 09:16 PM...01...14...55...00...ISS daily planning conference 09:51 PM...01...15...30...00...Group B computer powerup 10:06 PM...01...15...45...00...Rendezvous timeline begins 11:31 PM...01...17...10...00...Spacesuit removal from airlock 11:34 PM...01...17...13...26...NC-4 rendezvous rocket firing 04/07 01:06 AM...01...18...45...19...Ti burn; range = 9.2 miles 01:45 AM...01...19...23...54...Sunset 02:05 AM...01...19...43...55...Range = 10,000 ft 02:14 AM...01...19...52...35...Range = 5,000 ft 02:19 AM...01...19...58...04...Range = 3,000 ft 02:20 AM...01...19...59...09...Sunrise 02:23 AM...01...20...02...13...MC4 02:27 AM...01...20...06...13...Range = 1,500 ft 02:32 AM...01...20...11...13...Range = 1,000 ft 02:32 AM...01...20...11...18...RPM Start Window Open 02:35 AM...01...20...14...13...KU to LO (800 ft) 02:36 AM...01...20...15...13...Shuttle below ISS (725 ft) 02:41 AM...01...20...20...25...Range = 600 ft 02:43 AM...01...20...22...19...Start Pitch Maneuver 02:48 AM...01...20...27...16...Noon 02:51 AM...01...20...30...19...End Pitch Maneuver 02:54 AM...01...20...32...55...Initiate TORVA (575 ft) 02:56 AM...01...20...35...14...RPM Full Photo Window Close 03:05 AM...01...20...43...39...RPM Start Window Close 03:05 AM...01...20...44...25...Shuttle in front of ISS (310 ft) 03:06 AM...01...20...45...15...Range = 300 ft 03:10 AM...01...20...49...25...Range = 250 ft 03:15 AM...01...20...53...35...Range = 200 ft 03:16 AM...01...20...55...23...Sunset 03:17 AM...01...20...56...05...Range = 170 ft 12:19 PM...01...29...57...45...Range = 150 ft 03:23 AM...01...21...01...55...Range = 100 ft 03:26 AM...01...21...04...55...Range = 75 ft 03:30 AM...01...21...09...05...Range = 50 ft 03:33 AM...01...21...12...25...Range (30 ft) Station Keeping Start 03:38 AM...01...21...17...25...Push to Dock 03:43 AM...01...21...21...45...Range = 10 ft 03:44 AM...01...21...23...26...DOCKING 03:52 AM...01...21...30...40...Sunrise 04:11 AM...01...21...50...00...Leak checks 04:46 AM...01...22...25...00...Orbiter docking system prepped for ingress 04:41 AM...01...22...20...00...Group B computer powerdown 05:11 AM...01...22...50...00...Hatch open 05:41 AM...01...23...20...00...Welcome aboard! 05:56 AM...01...23...35...00...Safety briefing 06:31 AM...02...00...10...00...Spacesuits moved to Quest 06:31 AM...02...00...10...00...SRMS OBSS handoff 08:01 AM...02...01...40...00...REBA checkout 09:36 AM...02...03...15...00...ISS evening planning conference 11:51 AM...02...05...30...00...ISS crew sleep begins 12:21 PM...02...06...00...00...STS crew sleep begins
7:15 AM, 4/6/10, Update: Astronauts inspect shuttle heat shield; record data for downlink through space station
The Discovery astronauts carried out a detailed inspection of the shuttle's carbon composite nose cap and wing leading edge panels early Tuesday, storing video files on board because of a Ku-band antenna failure that is preventing high-speed data transmission to mission control.
Flight Director Richard Jones said the inspection, a now-routine part of all post-Columbia missions, went well and that the crew did not report any unusual, or obvious problems with the critical heat shield components, which experience the most extreme heating during re-entry.
Each 40-minute tape used to store the inspection data will be converted into a 7.2-gigabyte digital file for transmission to Earth using the Ku-band communications system aboard the International Space Station. Jones said five to six tapes were required, resulting in about 40 gigabytes of data that will be downlinked after docking early Wednesday.
"One of the biggest impacts we have suffered as a result (of the Ku-band antenna failure) is we haven't had a lot of the high rate data exchange with video, you're not going to see any of that, we haven't been able to get that down to the ground and we can't get it back up to the orbiter itself, either," he told reporters.
"We have been working very hard to overcome what the loss of the Ku antenna has done to our flight-day-two inspections, which we just finished accomplishing. The files that we normally send down, video files that the ground damage assessment team is looking at, that usually is coming down for the most part in real time and it's coming down normally through the Ku system.
"Since we don't have that, what we have put in place is a file conversion process where we're getting these video files and putting them on a tape and converting them to a digital file that we're going to downlink once we get docked to the International Space Station. So once we get docked, we're going to get those files to the ground as soon as possible."
While the problem will delay the damage assessment team's analysis, Jones said the work would get done in time to perform a more detailed "focused" inspection later in the mission if any problem areas are seen.
Engineers are still assessing how to carry out a second, "late" inspection that is normally conducted after the shuttle undocks from the space station. Without an operational Ku-band antenna system, Jones said the crew likely will carry out the second inspection while still docked to the lab complex.
The only other major Ku-related change in the crew's flight plan - aside from the loss of routine television views from the shuttle, email, remote commanding and mission control uplinks - involves procedures that will be used during the final stages of Discovery's rendezvous with the space station early Wednesday.
"That's a big day, obviously, getting docked with the International Space Station," Jones said. "That's our next major milestone. We had a chance to talk to the crew about radar failed procedures. We ... don't expect that radar to be functioning tomorrow. We're going to give it a shot, we're going to see if it actually comes up. If it does, we will use it appropriately. But if it doesn't, we've got procedures already built into our checklists on how to perform a rendezvous without that Ku radar available."
The last time a shuttle crew had to carry out a Ku-failed rendezvous was in 2000. But Jones said astronauts routinely train for dockings without a working radar.
"The (Discovery) crew, right before they launched, their last stand-alone (simulation) session they had, roughly about two weeks ago, they walked through this exact scenario, performing a rendezvous without the radar," Jones said. "So they're very familiar with it. ... We are very comfortable where we're at."
Along with inspecting the shuttle's heat shield Tuesday, the astronauts also checked out the spacesuits that will be used for three planned spacewalks during the docked phase of the mission to replace ammonia coolant tanks.
Commander Alan Poindexter and his six crewmates plan to go to bed around 12:21 p.m. Wakeup is scheduled for 8:21 p.m. The rendezvous timeline will being just after 10 p.m. and by 1:06 a.m. Wednesday, Discovery should be in position to begin the final phase of the rendezvous procedure, trailing the station by about nine miles. Docking is expected around 3:44 a.m.
8:55 PM, 4/5/10, Update: Astronauts gear up for heat shield inspection
The Discovery astronauts are preparing for a lengthy inspection of the shuttle's nose cap and wing leading edge panels to make sure the critical heat shield components came through launch without any major problems.
Because of trouble with the shuttle's Ku-band antenna system, the astronauts will be unable to immediately downlink video to mission control. As a result, they will record laser scans and imagery for downlink to analysts using the Ku-band communications system aboard the International Space Station after Discovery docks with the outpost Wednesday.
The antenna problem will delay the heat shield assessment and could force the astronauts to conduct a final heat shield inspection while the shuttle is docked to the station instead of immediately after undocking, which is the usual practice.
"We're still going to press ... with the flight-day-two inspection of the reinforced carbon carbon on the port and starboard (wing leading edge panels) and nose cap areas on Discovery," Flight Director Mike Safari said earlier Monday. "The crew's going to record all that information and then we'll transmit that over to station and downlink it from the station's Ku-band assets after we get docked.
"Other information that goes up, like the timeline modifications we have every morning as part of the mission, those are going to have to be verbalized up to the crew. It'll take a little bit longer in the morning to get the plan rolling as we've modified it overnight."
The heat shield inspection will be carried out by shuttle pilot James Dutton, Naoko Yamazaki and Dorothy Metcalf-Lindenburger using a 50-foot-long extension attached to the end of the shuttle's robot arm. The extension is called the Orbiter Boom Sensor System, or OBSS.
"We've got several sensors on the end of a long boom that we now carry up on the starboard side of the shuttle," Dutton said in a NASA interview. "We'll take the shuttle arm over and grab that boom and unberth (it), then use those sensors to essentially scan the leading edge and the underside of each of the wings, as well as around the nose of the shuttle to make sure we don't have any damage and, if we do have damage, to assess how big that damage is.
"It's a long day so we actually rotate through. There's three of us, Dottie, Naoko and myself, who will be the primary ones for operating the arm that day, and then (commander Alan Poindexter and Stephanie Wilson) will be sort of the backups where they will be standing back, using a couple of software programs we have to help watch clearances of the arm and the boom to the shuttle, and also to watch the configuration of the arm and make sure it's safe.
"So we essentially go through a very scripted set of maneuvers and collect the data that the ground needs ... so that they can then do the analysis to clear our thermal protection system for entry."
While the heat shield inspection is going on, astronauts Rick Mastracchio and Clay Anderson plan to check out the spacesuits they will use during three excursions when docked at the space station to swap out an ammonia coolant tank.
Here is an updated timeline of today's activity (in EDT and mission elapsed time; includes revision A of the NASA television schedule):
EDT........DD...HH...MM...EVENT 04/05 08:21 PM...00...14...00...Crew wakeup 09:56 PM...00...15...35...NC-2 rendezvous rocket firing 10:51 PM...00...16...30...Robot arm (SRMS) powerup 11:06 PM...00...16...45...SRMS checkout 11:21 PM...00...17...00...Ergometer setup 11:51 PM...00...17...30...SRMS unberths OBSS 11:51 PM...00...17...30...Spacesuit checkout preps 04/06 12:21 AM...00...18...00...Spacesuit checkout 01:06 AM...00...18...45...OBSS starboard wing survey 01:51 AM...00...19...30...Spacesuit prepped for transfer to station 03:01 AM...00...20...40...Crew meals begin 03:11 AM...00...20...50...OBSS nose cap survey 04:01 AM...00...21...40...OBSS port wing survey 05:01 AM...00...22...40...Middeck transfer preps 06:00 AM...00...23...39...Mission status briefing on NTV 06:16 AM...00...23...55...SRMS berths OBSS 07:21 AM...01...01...00...Centerline camera setup 07:26 AM...01...01...05...Rendezvous tools checkout 08:21 AM...01...02...00...OMS pod survey 09:32 AM...01...03...10...NC-3 rendezvous rocket firing 09:36 AM...01...03...15...Orbiter docking system ring extension 12:21 PM...01...06...00...Crew sleep begins 01:00 PM...01...08...39...Daily highlights reel on NTV 05:00 PM...01...10...39...Post-MMT briefing on NTV 08:21 PM...01...14...00...Crew wakeup
11:05 AM, 4/5/10, Update: Engineers troubleshoot problem with shuttle antenna (UPDATED at 4:55 PM with additional details)
The shuttle Discovery's Ku-band antenna system, used as a radar dish during rendezvous operations and to transmit video and data to and from the ground through NASA communications satellites, suffered a malfunction of some sort after the shuttle reached orbit Monday. Engineers are troubleshooting, but the system may be out of action for the duration of Discovery's mission.
"As far as the safety of the mission is concerned, we still have a lot of assets available at the International Space Station, so the safety of the mission in terms of making sure the heat shield on board Discovery and the overall health of the vehicle is fine," said Flight Director Mike Sarafin.
A shuttle Ku-band antenna, visible extending from the upper
right corner of the payload bay. (Credit: NASA)
The shuttle's Ku-band communications system uses a dish antenna deployed from the forward right corner of the cargo bay to track NASA communications satellites, allowing the crew to downlink data and video and ground controllers to uplink commands and instructions when the shuttle is not within range of a U.S. ground station.
The system has two electronics boxes that control its ability to track target satellites, relay data and act as a radar during rendezvous operations. During the crew's initial attempts to activate the Ku-band antenna after reaching orbit Monday, the system failed a self test. Engineers attempted to power cycle the hardware, but the troubleshooting efforts were not immediately successful.
"We've seen pieces of this failure mode in the past, but we haven't seen this exact failure mode and we're still evaluating ... to understand really what's going on," Sarafin said. "But we've got rules and procedures and workarounds in place, not only to handle a no-radar rendezvous case but also to work around the loss of the imagery and other data that we would normally get down early in the mission. We'll get that down a little bit later using the station assets."
In the near term, Sarafin said, the Discovery astronauts will record imagery and laser scan data from a heat shield inspection planned for Tuesday and then downlink the data to the ground after the shuttle docks with the space station Wednesday. As for the docking itself, the crew is trained to use other instruments to execute the shuttle's final approach and the loss of Ku radar capability is not expected to cause any major problems.
But it will affect the crew's timeline.
"Right now, we don't have any major timeline modifications in the short term or major mission objectives that are in jeopardy," Sarafin said. "We're still going to press tomorrow with the flight day two inspection of the reinforced carbon carbon on the port and starboard (wing leading edge panels) and nose cap areas on Discovery. The crew's going to record all that information and then we'll transmit that over to station and downlink it from the station's Ku-band assets after we get docked.
"Other information that goes up, like the timeline modifications we have every morning as part of the mission, those are going to have to be verbalized up to the crew. It'll take a little bit longer in the morning to get the plan rolling as we've modified it overnight. ... As far as installing the Multi Purpose Logistics Module and all the EVAs we've got ahead of us, we're not tracking any changes to that plan and the team is off evaluating if there are any mission objectives we need to talk about any further."
The shuttle astronauts normally would rely on the Ku-band antenna to downlink data from a post-undocking "late" inspection of the nose cap and wing leading edge panels. If the Ku issue is not resolved by then, Sarafin said mission managers could opt to have the astronauts carry out the second inspection while still docked to the space station.
"The team is very good at developing timelines that make the best use of the 13-day plan that we've got ahead of us and we just need to let them work through that," he said. "Should we need to do the late inspection for orbital debris risk mitigation late in the docked mission, we certainly have the capability to do that. The station team has already been made aware that's a possible outcome and they're working with the various users of the Ku equipment aboard the station to reserve a downlink channel should we not be able to recover the shuttle's Ku antenna."
6:50 AM, 4/5/10, Update: Shuttle Discovery rockets into space
The shuttle Discovery, carrying a crew of seven and 10 tons of supplies and equipment bound for the International Space Station, rocketed into orbit early Monday to kick off a three-spacewalk resupply mission.
With its three hydrogen-fueled main engines throttled up to full power, Discovery's twin solid-fuel boosters ignited with a crackling roar at 6:21:25 a.m. EDT, instantly pushing the spacecraft away from pad 39A.
The shuttle Discovery blasts off from pad 39A. (Photo: NASA TV)
Fifteen minutes before liftoff, the space station sailed 220 miles above the Kennedy Space Center, shining like a brilliant "star" as it streaked away to the northeast.
Discovery's launch, timed for the moment Earth's rotation carried the launch pad into the plane of the station's orbit, occurred 22 minutes before the start of civil twilight and 46 minutes before sunrise.
Lighting up a clear pre-dawn sky, Discovery climbed into sunlight less than two minutes after liftoff, the churning cloud of exhaust from the shuttle's two boosters suddenly illuminated in a ghostly display for area residents and tourists.
The shuttle's climb to space appeared uneventful. A camera mounted on the side of the ship's external tank spotted a few pieces of presumed foam insulation falling away four minutes and 18 seconds after liftoff, but that was well after the shuttle had left the dense lower atmosphere where debris impacts pose the greatest threat.
Pieces of debris - presumed foam insulation - fall away to
the left, illuminated by the sun. (Photo: NASA TV)
Eight-and-a-half-minutes after liftoff, the shuttle slipped into its planned preliminary orbit. If all goes well, commander John Poindexter and pilot James Dutton will guide the orbiter to a docking with the space station's forward port at 3:44 a.m. Wednesday.
Joining Poindexter and Dutton aboard Discovery were flight engineer Dorothy Metcalf-Lindenburger, Stephanie Wilson, Japanese astronaut Naoko Yamazaki and spacewalkers Richard Mastracchio and Clayton Anderson, veteran of a long-duration stay aboard the station in 2007.
"The biggest objective is to bring the multi-purpose logistics module, the MPLM, and attach it to the station so that we can empty it," said Anderson. "The MPLM has all sorts of cargo and supplies, experiments, racks, food, clothing. We need to get all that stuff onto the station (to make) it easier for them to sustain themselves over time.
"Then the second really big task that we have are the EVAs, the spacewalks that Rick Mastracchio and I will do. The main point of those is to replace a couple key pieces of hardware, the ammonia tank assembly on the outside of the station and then a rate gyro assembly that helps the station understand what its attitude is."
A closeup of the shuttle's main engines and boosters
during the early stages of ascent. (Photo: NASA TV)
The space station is equipped with two independent coolant loops that dissipate the heat generated by the lab's electrical systems by circulating ammonia coolant through large radiator panels.
"ItÕs like Freon in your air conditioner at home but we use ammonia on the outside of the station," Anderson said. "So we have a huge tank, it's about (1,700) pounds. It's probably the size of a double refrigerator-freezer component and it lives on the backside toward the center of the station and there are actually two, one on the right and one on the left. The one on the left has recently been changed out by another shuttle crew. So we're going to change the one on the right."
Discovery's launching continues an extremely busy period in the life of the space station, coming three days after launch of a Russian Soyuz capsule from Kazakhstan carrying three fresh crew members - cosmonauts Alexander Skvortsov, Mikhail Kornienko and NASA astronaut Tracy Caldwell Dyson.
The Soyuz TMA-18 spacecraft docked with the station early Sunday and its crew joined Expedition 23 commander Oleg Kotov, Japanese astronaut Soichi Noguchi and NASA flight engineer Timothy Creamer. The expanded Expedition 23 crew will, in turn, welcome the Discovery astronauts to the lab complex two days after the shuttle's launching.
"We're absolutely delighted to have our friends and comrades joining us here in a couple of days," Creamer radioed from the station after watching Discovery's launch.
"Stand by for a knock on the door," a flight controller replied.
The shuttle Discovery as viewed from the Kennedy Space
Center press site. (Photo: NASA TV)
With the shuttle program facing retirement later this year after a final four missions, the space station program is racing the clock to complete the outpost and stock it with supplies and spare parts before the heavy lift orbiter is grounded for good.
Kirk Shireman, deputy manager of the space station program at the Johnson Space Center in Houston, said that along with the final four shuttle missions, the program expects three more Soyuz crew launches this year, four Soyuz landings, six launches of unmanned Progress supply ships, launch of a European Space Agency Automated Transfer Vehicle resupply mission and six station-based spacewalks above and beyond the EVAs planned by visiting shuttle crews.
"So you can see, it's a busy time," he said. "The program focus is turning away from assembly. We're looking forward to fully utilizing ISS and extending the International Space Station to 2020. We'll have a very busy year and we're very much looking forward to it."
3:40 AM, 4/5/10, Update: Astronauts strap in for launch
The shuttle Discovery's crew strapped in early Monday, awaiting liftoff on a space station assembly mission. There are no technical problems of any significance at pad 39A and launch remains targeted for 6:21:25 a.m. EDT.
The Discovery astronauts depart crew quarters and head
for the launch pad. (Photo: NASA TV)
Commander Alan Poindexter climbs up to his seat on Discovery's
flight deck. (Photo: NASA TV)
The weather is generally favorable, and while meteorologists are monitoring a bit more cloud cover than was initially expected, the forecast remains "go" for launch.
12:50 AM, 4/5/10, Update: Shuttle fueling complete
The shuttle Discovery's external tank has been loaded with a half-million gallons of liquid oxygen and hydrogen rocket fuel. There are no technical problems of any significance at pad 39A, forecasters are continuing to predict an 80 percent chance of good weather and launch remains on track for 6:21:25 a.m. EDT.
The only issue of any note so far was a brief spike in the output of fuel cell No. 2 during its activation late Sunday. Engineers believe the spike was the result of a cockpit lighting configuration and not an actual problem. They will collect more data when the crew begins strapping in just after 3 a.m.
09:30 PM, 4/4/10, Update: 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 late Sunday, setting the stage for a pre-dawn Monday launch on a space station resupply mission.
The three-hour fueling procedure began at 9:28 p.m. EDT as super cold propellants began flowing from huge storage dewars through transfer lines to the shuttle atop launch pad 39A. If all goes well, the procedure will be completed around 12:30 a.m.
The shuttle Discovery atop pad 39A. (Credit: NASA TV)
The start of fueling was delayed about a half hour after engineers noticed a brief post-activation spike in the output of fuel cell No. 2, one of three that generate the shuttle's electrical power. Engineers suspect the spike was triggered by a cockpit lighting configuration and was not an indication of an actual problem with the fuel cell.
NASA television coverage of launch preparations is scheduled to begin at 1:15 a.m. and Discovery's crew - commander Alan Poindexter, pilot James Dutton, flight engineer Dorothy Metcalf-Lindenburger, Stephanie Wilson, Japanese astronaut Naoko Yamazaki and spacewalkers Richard Mastracchio and Clayton Anderson - will begin strapping in around 3 a.m.
Discovery's liftoff on the 131st shuttle mission is targeted for 6:21:25 a.m., roughly the moment Earth's rotation carries the pad into the plane of the space station's orbit. The 13-minute 10-second launch window closes at 6:29:35 a.m. Forecasters are predicting an 80 percent chance of good weather.
Here is a timeline of major countdown events and flight day one activity (in EDT):
EDT...........EVENT 11:56 PM......Begin 2-hour 30-minute built-in hold (T-minus 3 hours) 11:56 PM......Closeout crew to white room 11:56 PM......External tank in stable replenish mode Mon 04/05/10 12:11 AM......Astronaut support personnel comm checks 12:41 AM......Pre-ingress switch reconfig 01:15 AM......NASA TV launch coverage begins 01:56 AM......Final crew weather briefing 02:01 AM......Crew suit up begins 02:26 AM......Resume countdown (T-minus 3 hours) 02:31 AM......Crew departs O&C building 03:01 AM......Crew ingress 03:51 AM......Astronaut comm checks 04:16 AM......Hatch closure 04:46 AM......White room closeout 05:06 AM......Begin 10-minute built-in hold (T-minus 20m) 05:16 AM......NASA test director countdown briefing 05:16 AM......Resume countdown (T-minus 20m) 05:17 AM......Backup flight computer to OPS 1 05:21 AM......KSC area clear to launch 05:27 AM......Begin final built-in hold (T-minus 9m) 05:57:25 AM...NTD launch status verification 06:12:25 AM...Resume countdown (T-minus 9m) 06:16:25 AM...Orbiter access arm retraction 06:16:25 AM...Launch window opens 06:16:25 AM...Hydraulic power system (APU) start 06:16:30 AM...Terminate liquid oxygen replenish 06:17:25 AM...Purge sequence 4 hydraulic test 06:17:25 AM...Inertial measurement units to inertial 06:17:30 AM...Aerosurface profile 06:17:55 AM...Main engine steering test 06:18:30 AM...Liquid oxygen tank pressurization 06:18:50 AM...Fuel cells to internal reactants 06:18:55 AM...Clear caution-and-warning memory 06:19:25 AM...Crew closes visors 06:19:28 AM...Liquid hydrogen tank pressurization 06:20:35 AM...Booster joint heater deactivation 06:20:54 AM...Shuttle computers take control of countdown 06:21:04 AM...Booster steering test 06:21:18 AM...Main engine start (T-6.6 seconds) 06:21:25 AM...Booster ignition (LAUNCH) 06:21:35 AM...Shuttle roll begins 06:21:43 AM...Roll program complete 06:22:03 AM...Main engine throttle down to 72 percent 06:22:17 AM...Main engine throttle up to 104.5 percent 06:22:24 AM...Maximum aerodynamic pressure (695 pounds per square foot) 06:23:30 AM...Booster separation 06:24:00 AM...Trans-Atlantic abort options available 06:25:12 AM...KSC abort options end (negative return) 06:26:36 AM...Abort to orbit options available 06:27:12 AM...The shuttle rolls to a heads up orientation 06:27:40 AM...The shuttle can reach its planned orbit with one engine out 06:29:49 AM...Main engine cutoff command 06:34:00 AM...Launch replays on NASA TV 07:30:00 AM...Post-launch news conference on NASA TV 07:46:00 AM...Payload bay doors open 10:56:00 AM...External tank video downlink 12:21:00 PM...Crew sleep begins 08:21:00 PM...Crew wakeup (begins flight day 2)
2:00 PM, 4/3/10, Update: MMT clears Discovery for launch; weather still 80 percent 'go'
NASA's Mission Management Team reviewed the shuttle Discovery's launch processing Saturday, discussed two recent booster issues and received a favorable weather forecast, giving engineers a unanimous "go" to proceed with launch Monday on a space station resupply mission.
With work on the ground in high gear, the crew of the Soyuz TMA-18 spacecraft, launched from the Baikonur Cosmodrome in Kazakhstan early Friday, continued its approach to the International Space Station, gearing up for a docking around 1:26 a.m. EDT Sunday to cap a two-day orbital chase.
Soyuz commander Alexander Skvortsov, Mikhail Kornienko and Tracy Caldwell Dyson will join Expedition 23 commander Oleg Kotov, Japanese astronaut Soichi Noguchi and NASA flight engineer Timothy Creamer, aboard the lab complex, boosting the station's full-time crew back up to six.
The new arrivals will face a hectic first few days in orbit, learning their way around the space station while preparing for the arrival of Discovery later in the week.
At the Kennedy Space Center, engineers are readying the space shuttle for liftoff at 6:21:23 a.m. Monday. A protective gantry will be pulled away from the spacecraft around 9:30 a.m. Sunday and engineers will load the ship's external tank with a half-million gallons of liquid oxygen and hydrogen rocket fuel starting around 8:56 p.m.
Commander Alan Poindexter, pilot James Dutton, flight engineer Dorothy Metcalf-Lindenburger, Stephanie Wilson, Japanese astronaut Naoko Yamazaki and spacewalkers Richard Mastracchio and Clayton Anderson plan to begin strapping in just after 3 a.m. Monday to await liftoff on the 131st shuttle mission.
Shuttle weather officer Kathy Winters said forecasters are predicting an 80 percent chance of good weather Monday and Tuesday, dropping to 70 percent "go" on Wednesday. The primary concern Monday is a chance for ground fog that could reduce visibility for a return-to-launch-site abort.
"We've had fog in the area the last couple of days," she said. "This morning, though, it did not happen nearly as much, just down to five nautical mile visibility, which is a go (observation). So right now, it does look like things are starting to improve."
Launch Director Pete Nickolenko said the countdown was proceeding smoothly and "we're on track and ready to go for Monday."
He said NASA can made back-to-back launch tries Monday and Tuesday or make attempts Monday and Wednesday. After the second try, the team would stand down for 72 hours to top off the shuttle's fuel cell hydrogen and oxygen supplies.
Mike Moses, chairman of NASA's Mission Management Team, said two late-breaking booster issues were discussed Saturday, both involving anomalies seen in booster hardware used for ground testing.
In a test motor recently fired in Utah, engineers discovered unusual charring in a small section of insulation between the case of the booster segment and the solid propellant where two segments were bolted together. Engineers suspect the charring was the result of an air bubble in an inhibitor that is applied the the propellant where segments are bolted together to prevent unwanted burning in that interface.
Taking a conservative approach, Moses said engineers modeled worst-case scenarios and concluded that even if no insulation was present, the booster would still operate within NASA's safety guidelines.
"They just layered up conservatism over conservatism and even when they did all that, we showed that we'd get about an extra 90 square inches of propellant burning for about seven seconds and that causes us no problem whatsoever," Moses said.
"From a ballistics standpoint, everything is good, structurally everything is good and thermally, the casing and the case joint still maintains a factor of safety greater than 2.6, which is well above our required safety factor. So even in that worst case, we're still well above our margin."
Another issue reviewed by the MMT was the failure of a speed sensor in a booster hydraulic power unit being "hot fired" prior to a ground test. The hydraulic power units direct hot gas through a turbine that drives a pump to generate the hydraulic muscle needed to move the booster's nozzle for steering.
In the ground test firing, a speed sensor failed, apparently the result of a wire breaking. Moses said a similar failure in one of Discovery's hydraulic power units would simply trigger a launch delay if it occurred before liftoff. The power units are equipped with redundant sensors and if a failure happened after launch, the flight would continue using the other sensor.
"To wrap it all up, at the end of the day, a unanimous poll from the MMT that we're go to launch," Mosses said. "We're really excited about this mission."
The goal of Discovery's flight is to deliver some 10 tons of supplies and equipment to the space station, including ammonia coolant, science wracks, an experiment sample freezer, a crew sleep station and a darkroom-like enclosure for the U.S. lab module's optical-grade window.
1:22 PM, 4/3/10, Update: Shuttle countdown begins; weather 80 percent 'go' for Monday launch
With good weather expected, the shuttle Discovery's countdown began early Friday, setting the stage for a pre-dawn Monday launch to kick off a space station science and resupply mission.
The countdown began at 3 a.m. EDT, three hours after the successful launch of a Russian Soyuz spacecraft from Kazakhstan carrying a crew of three to the station. NASA Test Director Steve Payne said preparations for Discovery's launching "are going extremely well, there are no issues to report."
Liftoff is targeted for 6:21:23 a.m. Monday, roughly the moment Earth's rotation carries launch complex 39A into the plane of the International Space Station's orbit.
Kathy Winters, the shuttle weather officer, said the only concern is a chance of fog. But overall, the forecast for Monday and Tuesday calls for an 80 percent chance of acceptable conditions.
"Weather is looking very good right now at KSC," she said. "We've been experiencing some really nice weather, it's going to continue into launch day. The only concern we do have is for fog to form the morning of launch.
"Right now, we're forecasting a wind from the east. It's very light, though, and if it happens to turn around and give us a land breeze, the temperatures could drop enough to saturation and cause some fog in the area. We have a four-mile visibility constraint for return-to-launch-site weather. So that's our primary concern for launch and right now, we're going with a 20 percent chance of that occurring."
Early Sunday, during a long hold in Discovery's countdown, the Soyuz TMA-18 spacecraft launched from the Baikonur Cosmodrome in Kazakhstan Friday will dock with the space station.
Soyuz commander Alexander Skvortsov, Mikhail Kornienko and Tracy Caldwell Dyson, a shuttle veteran, will be welcomed aboard by Expedition 23 commander Oleg Kotov, Soichi Noguchi and NASA flight engineer Timothy Creamer.
The new arrivals will face a particularly busy first few days aboard the lab complex as the expanded Expedition 23 crew works to complete preparations for Discovery's arrival next week.
A few hours after the Soyuz docking Sunday, engineers at the Kennedy Space Center will roll a protective gantry away from Discovery, exposing the shuttle to view and setting the stage for the start of fueling at 8:56 p.m.
The shuttle astronauts - commander Alan Poindexter, pilot James Dutton, flight engineer Dorothy Metcalf-Lindenburger, Stephanie Wilson, Japanese astronaut Naoko Yamazaki and spacewalkers Richard Mastracchio and Clayton Anderson - plan to strap in around 3 a.m. Monday to await liftoff.
The goal of the 131st shuttle mission is to deliver 10 tons of supplies and equipment to the space station, including ammonia coolant, science racks, an experiment sample freezer and a crew sleep station.
The mission will be carried out in the deep overnight hours U.S. time. Assuming an on-time launch, the shuttle will dock with the space station around 3:44 a.m. Wednesday. Three spacewalks are planned, the first starting at 1:41 a.m. on April 9; the second at 2:16 A.M. on April 11; and the third at 3:11 a.m. on April 13.
If all goes well, Discovery will undock from the lab complex around 3:55 a.m. on April 16 and land back at the Kennedy Space Center two days later at 8:29 a.m.
9:55 AM, 4/3/10, Update: STS-131 Mission Preview (UPDATED with Soyuz docking)
The shuttle Discovery, carrying a crew of seven and 10 tons of supplies and equipment bound for the International Space Station, is poised for blastoff April 5 on a three-spacewalk mission to deliver ammonia coolant, experiment hardware, a darkroom, a crew hygiene station and an experiment sample freezer.
The Discovery astronauts also plan to deliver spare parts for the station's water recycling system in an ongoing effort to work the bugs out of the complex life support equipment before the shuttle's retirement later this year.
"We didn't really know how to design this hardware at the beginning," said Bill Gerstenmaier, NASA's chief of space operations. "We did as good as we could and now we're actually working those bugs out. This is important for us to have the shuttle around for these couple of flights so we can get the water systems and the life support systems up and operating."
Mission managers cleared Discovery for launch after deciding a failed helium isolation valve in the ship's right-side aft rocket pod posed no significant threat to crew safety or meeting the flight's objectives. Likewise, a review showed suspect ceramic inserts around critical bolts were unlikely to shake free and pose an impact threat during launch or re-entry.
With Discovery ready to go, spacewalker Clay Anderson, veteran of a long-duration stay aboard the station in 2007, said the crew was anxious to get on with a complex mission.
"The biggest objective is to bring the multi-purpose logistics module, the MPLM, and attach it to the station so that we can empty it," he said. "The MPLM has all sorts of cargo and supplies, experiments, racks, food, clothing. We need to get all that stuff onto the station (to make) it easier for them to sustain themselves over time.
"Then the second really big task that we have are the EVAs, the spacewalks that Rick Mastracchio and I will do. The main point of those is to replace a couple key pieces of hardware, the ammonia tank assembly on the outside of the station and then a rate gyro assembly that helps the station understand what its attitude is."
The space station is equipped with two independent coolant loops that dissipate the heat generated by the lab's electrical systems by circulating ammonia coolant through large radiator panels.
"ItÕs like Freon in your air conditioner at home but we use ammonia on the outside of the station," Anderson said. "So we have a huge tank, it's about (1,700) pounds. It's probably the size of a double refrigerator-freezer component and it lives on the backside toward the center of the station and there are actually two, one on the right and one on the left. The one on the left has recently been changed out by another shuttle crew. So we're going to change the one on the right."
Discovery's launching continues an extremely busy period in the life of the space station, coming three days after the planned launch of a Russian Soyuz capsule from Kazakhstan carrying three fresh crew members - cosmonauts Alexander Skvortsov, Mikhail Kornienko and NASA astronaut Tracy Caldwell Dyson.
If all goes well, the Soyuz TMA-18 spacecraft will dock with the station April 4 and its crew will join Expedition 23 commander Oleg Kotov, Japanese astronaut Soichi Noguchi and NASA flight engineer Timothy Creamer. The expanded Expedition 23 crew will, in turn, welcome the Discovery astronauts to the lab complex two days after the shuttle's launching.
"It really brings out the essence of our International Space Station and our program that we could have a shuttle and a Soyuz launching within days of each other and how we can integrate and add to the already complex nature of what we do and the business we're in," Caldwell said before launch.
With the shuttle program facing retirement later this year after a final four missions, the space station program is racing the clock to complete the outpost and stock it with supplies and spare parts before the heavy lift orbiter is grounded for good.
Kirk Shireman, deputy manager of the space station program at the Johnson Space Center in Houston, said that along with the final four shuttle missions, the program expects three more Soyuz crew launches this year, four Soyuz landings, six launches of unmanned Progress supply ships, launch of a European Space Agency Automated Transfer Vehicle resupply mission and six station-based spacewalks above and beyond the EVAs planned by visiting shuttle crews.
"So you can see, it's a busy time," he said. "The program focus is turning away from assembly. We're looking forward to fully utilizing ISS and extending the International Space Station to 2020. We'll have a very busy year and we're very much looking forward to it."
Discovery's liftoff from pad 39A at the Kennedy Space Center is targeted for 6:21:25 a.m. EDT on April 5, roughly the moment Earth's rotation carries the shuttle into the plane of the space station's orbit. The shuttle has enough power to launch five minutes to either side of that "in-plane" moment but NASA typically targets the middle of the 10-minute window to maximize ascent performance.
Joining shuttle veteran Alan Poindexter, the commander, on Discovery's flight deck will be rookie pilot James Dutton, veteran spacewalker Mastracchio and flight engineer Dorothy Metcalf-Lindenburger, a former high school teacher and astronomy enthusiast making her first flight.
Seated on the shuttle's lower deck will be shuttle veteran Stephanie Wilson, Japanese astronaut Naoko Yamazaki, making her first flight, and Anderson.
Assuming an on-time liftoff, Poindexter will guide Discovery to a docking at the space station's forward port around 3:44 a.m. on April 7. Late that evening, the Leonardo multi-purpose logistics module, loaded with 8.5 tons of supplies and equipment, will be pulled from the shuttle's cargo bay and attached to the space station's Unity module just after midnight.
The next day, Mastracchio and Anderson will stage the first of three spacewalks needed to install the ammonia coolant tank on the space station's main power truss. A spent ammonia tank will be removed and placed back in the shuttle's cargo bay for return to Earth and relaunch later this year.
Discovery is scheduled to undock from the station around 3:55 a.m. on April 16, setting up a landing back at the Kennedy Space Center around 8:29 a.m. on April 18.
The daylight landing time is the result of a recent decision to switch from a southwest-to-northeast "ascending node" re-entry trajectory, one that carries a Florida-bound shuttle over the Pacific Ocean, Central America and the Caribbean, to one that will carry Discovery from northwest to southeast over the heartland of America.
This will be only the second such "descending node" entry since the Columbia disaster. Shuttle Program Manager John Shannon said the change was ordered to give the crew more time to complete the required supply transfers and to move the landing from darkness to daylight. He said the shuttle would not fly over any population centers on its way down and that a NASA analysis showed the risk to the public was minimal.
"Post Columbia, we were very deliberate in trying to determine risks to people on the ground if we had a vehicle break up," he said. "We did some extensive modeling of what debris envelopes would be created for different vehicle breakups. It's a difficult thing to talk about, but it's important work we do.
"You take a look at the ground track of the vehicle and you look at the different debris footprints for breakups at different altitudes and then you sum all that together and you come up with a certain risk to the population. What we have done here is take a very close look and make sure the descending node opportunities, which will go over the United States, do not put any major population areas at risk and that our general population risk is below those limits that were set."
By switching to a descending node entry, "the significant advantage you get for the crew timeline really said this was the way to go," Shannon said.
The return route will be familiar to Wilson and Anderson. They were part of the STS-120 crew that flew the only other post-Columbia descending node entry in November 2007.
While only four more shuttle flights are officially on the books, scheduled for launch April 5, May 14, July 29 and Sept. 16, NASA managers are holding out hope that a fifth mission will be added to the manifest, a flight that would use the external tank and boosters set aside for an emergency rescue mission in case of problems with the last currently planned flight.
Launching a fifth mission with a crew of four, NASA could rely on the space station and Russian Soyuz ferry craft to provide emergency return capability, eliminating the need for a dedicated shuttle rescue flight.
President Barack Obama plans to visit the Kennedy Space Center during Discovery's mission to discuss the shuttle program's looming retirement, projected job losses and his administration's proposed cancellation of NASA's Constellation moon program.
If the administration ultimately supports an additional shuttle flight, as urged by Sen. Bill Nelson, D-Fla., and other lawmakers, NASA officials believe all five flights could be completed before the end of the calendar year. But a decision is needed by late April, officials say, for crew selection, training and flight planning.
A BUSY MISSION FOR DISCOVERY'S CREW
The initial stages of Discovery's mission will follow NASA's post-Columbia template, designed to make sure any damage to the shuttle's fragile heat shield is spotted and fully assessed.
Following launch, the astronauts will beam down digital pictures and video of the shuttle's external tank to help engineers determine the health of the foam insulation on the ship's external tank.
That imagery, combined with footage shot from the ground and a camera mounted on the side of the huge fuel tank will show whether any insulation or other debris fell away during launch and impacted Discovery's heat shield tiles or the reinforced carbon carbon wing leading edge panels that experience the most extreme heating during re-entry.
On the second day of the mission, the astronauts will unlimber Discovery's robot arm and attach a 50-foot-long extension equipped with a laser scanner and camera. Using the orbiter boom sensor system, or OBSS, the crew will scan the leading edge panels on both wings and the RCC nose cap to look for any signs of impact damage.
Anderson and Mastracchio, meanwhile, will test their spacesuits and the tools they plan to use during their upcoming spacewalks while Poindexter and Dutton carry out two rocket firings to fine-tune the shuttle's path to the space station.
Approaching the lab complex from behind on flight day three, Poindexter will guide Discovery to a point about 600 feet directly below the station. Once in position, he will execute a 360-degree rendezvous pitch maneuver, or RPM, rotating the shuttle through a complete back flip to expose the ship's belly to the station crew.
Using digital cameras with 400 mm and 800 mm lenses, Kotov and Creamer will photograph the underside of the orbiter to look for any signs of damage. They also will photograph the shuttle's upper surfaces and downlink the imagery to Houston for detailed analysis.
From there, Poindexter will manually guide Discovery up to a point about 400 feet directly in front of the space station with the shuttle's nose pointed toward deep space and its open payload bay facing a docking port on the forward end of the Harmony module.
"We wake up in the morning of rendezvous day and get right to work setting up our tools and making sure that we have all the equipment we need for the rendezvous," Poindexter said. "The folks on the ground have been working hard up to this point to get us to the right point to execute the rendezvous. We do a series of burns or maneuvers to bring the shuttle up underneath the space station at about 1,000 feet.
"We fly directly below the station to a distance of about 600 feet and from there we'll execute the rendezvous pitch maneuver, which allows the space station crew to image the orbiter's thermal protection system with some high-powered cameras. We'll then manually fly the shuttle up in front of the station to a distance of about 400 and then slowly back it into the space station's docking port. That's all done manually from the aft cockpit and I've got a lot of help on the flight deck with some real professional crew members who are doing most of the hard work."
After leak checks, hatches between Discovery and the station will be opened and Kotov and his crewmates will welcome Poindexter and company on board.
It will be a reunion of sorts for Wilson, Anderson, Dyson and Mastracchio, who all flew together on previous shuttle/station missions.
"I think it rocks, I'm really excited," Dyson said before launch. "These are some great friends of mine on the shuttle, I've flown with some of them, I've trained with some of them and I've shared a lot of dinners and good times with these folks. And I'm delighted for them and just ecstatic that the timing worked out for us to be in space together."
After a short safety briefing, the combined crews will get to work, transferring the spacesuits needed by Anderson and Mastracchio to the station's Quest airlock module and using the lab's robot arm to pull the OBSS out of the shuttle's cargo bay. The station arm will hand the OBSS off to the shuttle's robot arm for a possible "focused" inspection later, if any signs of heat shield damage are spotted.
The next day - flight day four - Wilson and Dutton will use the station's robot arm to pull the Leonardo MPLM out of Discovery's cargo bay so it can be attached to the Unity module's Earth-facing, or nadir, port. Loaded with cargo, the module weighs 27,274 pounds, including the 9,632-pound weight of the MPLM itself.
After a break for lunch, the astronauts will prepare the vestibule between Unity and Leonardo, open hatches and enter the cargo module for the first time. Mastracchio and Anderson, meanwhile, will close out the day by spending the night in the Quest airlock module at a reduced pressure of 10.2 pounds per square inch.
The so-called "campout" procedure helps spacewalkers purge nitrogen from their bloodstreams and prevent the bends after working in NASA's 5-psi spacesuits.
Assuming an on-time launch, the mission's first spacewalk will begin around 1:40 a.m. on April 9. It will take three excursions to move the new ammonia tank into position, remove the old tank, plumb the new assembly in its place and then move the old tank back to the shuttle.
"I think the biggest challenge of every EVA of this magnitude is the integration of the robotics and the EVA guys," Mastracchio said. "It's a real team effort. Inside, we'll have Stephanie and Jim working the arm, we'll have Dottie calling the shots as (spacewalk coordinator) and then Clay and I outside. And of course, we're working closely with the ground.
"The real challenge here is this ammonia tank that we're moving is taking three EVAs, or part of three EVAs, to get it done. Our first EVA, we'll remove the new ammonia tank from the shuttle and get it onto the station (where) we'll temp stow it. The second EVA, we'll actually swap the two ammonia tanks, the new one for the old one and then on the third EVA, we'll be moving the old tank from the space station into the space shuttle's payload bay for return. That's the biggest challenge. Between each EVA, we'll have to move the robotic arm, it has to walk off to a new work site. So there's a lot of teamwork and a lot of integration involved."
During Anderson's 2007 stay aboard the station, he participated in a spacewalk with Mastracchio during a July shuttle assembly mission.
"Rick and I are very familiar with each other," Anderson said. "We have a lot of hours of pool time together, we understand each other's strengths and weaknesses and we really enjoy working together. I think that in and of itself bodes well for what we're going to do on these three EVAs."
During the first spacewalk, Anderson and Mastracchio will disconnect ammonia and nitrogen pressurization lines from the old tank, then move to the shuttle's cargo bay where they will detach the new ammonia tank assembly from its mount and hand it off to the station's robot arm.
Wilson and Dutton, operating the space arm, will move the new ATA to a temporary mounting point on the crane's mobile base. While that is going on, the spacewalkers will install a replacement rate gyro assembly and then move to the far left end of the station's solar power truss to loosen bolts holding a massive battery pack in place. The batteries will be replaced on an upcoming shuttle flight.
"What I'll look forward to the most on these EVAs, we'll actually be crawling out to the farthest reaches of the station on the left side to do some work on some batteries out there," Anderson told CBS News. "Plus, Rick gets to go out to the Japanese Exposed Facility and do some work and then I'll be on the other side on the Columbus module doing some work and I've never seen those views.
"When I was up there and did my spacewalks before, it was a totally different configuration, so I'm really looking forward to being out on the edge, if you will, and seeing the views that we have and taking some pictures and just having a little bit of fun."
While Anderson and Mastracchio are working outside, the astronauts inside the station will be working to unload the Leonardo MPLM. Among the items scheduled for transfer during the spacewalk are the minus 80-degree experiment sample freezer, known by the acronym MELFI, and a new crew cabin, the fourth and final U.S. cabin to be moved to the station.
NASA's original plan was to equip the sleep station with a curtain-like liner to turn it into a bathing and hygiene cabinet.
"It's a space shower," Shireman said. "We don't really take showers on board the ISS, but people need to bathe and shampoo their hair and because it can release free water, we like to do it in a place that won't allow the water to float and get into avionics, electrical equipment, that can cause damage.
"So we actually put a liner in there. It's not as simple as you would think. It's not just a shower curtain, it's a little more complicated than that. But it's a station with privacy where the crew members can go and clean up. A very important thing from a health standpoint and also a psychological standpoint."
But with the arrival of the Soyuz TMA-18 spacecraft, the Expedition 23 crew will include three Russians. The Russian segment of the station only has two crew sleep stations and a third will not be available until 2012 when a new Russian lab module is launched. NASA may let the Russians use the new U.S. crew cabin as needed until then and instead use the toilet compartment in the Tranquility module as a hygiene station.
Following the first spacewalk, the astronauts will spend flight day six moving supplies and equipment out of the MPLM and into the station, including an experiment rack and the Window Observational Research Facility, or WORF. The WORF rack will be installed in a bay in the U.S. Destiny lab module that features a high-quality window. Along with limiting stray light, the facility will provide attachment points for various still and video cameras, as well as other optical instruments, for enhanced Earth observations.
The next day, after another airlock campout, Anderson and Mastracchio will devote flight day seven to their second spacewalk. After unbolting the old ammonia tank assembly, Wilson and Dutton will move it to a crew equipment cart on the front side of the station's main power truss and the spacewalkers will secure it with tethers.
The arm then will move to the new ATA, grapple it and move it into position for installation in the power truss. Manually maneuvering the massive tank, the astronauts will move it into place, install four bolts and reconnect the ammonia and nitrogen pressurization lines.
"During each of the EVAs, we have to hold the ATA, this ammonia tank, up over our heads," Mastracchio said. "It's about an 1,800-pound tank, I think. Clay's going to do it on EVA 1; then I do it on EVA 2. We're going to be holding this tank over our heads, trying to control it while Jim and Stephanie come in and grapple it. So I'm a little concerned about trying to have the stability to hold that tank nice and firm and steady ... so they can come in and grapple it."
With the new tank in place, Mastracchio and Anderson will move to the front side of the truss, untether the old tank and hand it off to the robot arm. The old tank will be temporarily mounted on the mobile base station where the new tank was stowed after its initial removal from the shuttle's cargo bay.
The next day - flight day eight - the combined crews will enjoy a half day of off-duty time, after which they will continue with MPLM unloading. Along with moving muscle atrophy experiment hardware into the station, they also will install a panel in the new seven-window cupola to fix a clearance problem that has prevented installation of a robotics work station.
The cupola, attached during a February shuttle mission as part of the new Tranquility module, will provide robot arm operators with panoramic, line-of-sight views to approaching cargo ships and work sites around the station.
Flight day nine will be devoted to the third spacwewalk and completing the ammonia tank transfer tasks. The robot arm will carry the depleted tank from its temporary storage point on the mobile base station to the back of Discovery's cargo bay where Mastracchio and Anderson will bolt it in place for the return to Earth.
With the old tank secure, Anderson, his feet anchored to the end of the robot arm, will be moved to the outboard side of the European Columbus module to retrieve an experiment mounting plate assembly. He and Mastracchio will mount the plate in the shuttle's cargo bay. Anderson then will move to the Canadian Special Purpose Dexterous Manipulator robot to install a second camera while Mastracchio replaces a camera light on the Destiny module.
"EVA 3 is kind of a miscellaneous EVA," Anderson said. "We have lots of different tasks we're going to do. Most notably we'll do some work with the Special Purpose Dextrous Manipulator that we like to call DEXTRE. I'll be doing some work on that one. I'll remove some thermal insulation that's been there for a while that needs to go away. I'll take that out and also I will be working on installing a camera that goes onto one of the camera locations, and Rick will also be doing some camera work, but he'll be doing it in a different place, on the lab module. There's a camera that needs to be fixed. It needs to be removed and replaced and RickÕs going to do that task."
The astronauts will wrap up equipment transfers from the MPLM the following day, hold a traditional in-flight news conference and take another half day off.
Flight day eleven will be devoted to completing the MPLM transfers and deactivating the cargo module. After hatches are closed, motorized bolts will be driven to detach the module from Unity's nadir port, and the station's robot arm will move it back to Discovery's cargo bay for the trip home.
After that, the combined crews plan to gather in the Harmony module for one final time to bid each other farewell. Hatches between the spacecraft will be closed at the end of the day and the docking port depressurized.
The next morning, with Dutton at the controls on Discovery's flight deck, Discovery will undock and depart.
"It's the day I'm really looking forward to," Dutton said. "The pilot's big moment of glory is getting to do the fly around of the space station. So we'll undock, back away around 400 to 450 feet in front of the space station and then begin to fly a maneuver over the top in front of the space station, essentially complete a 360-degree arc around the space station.
"Then we'll continue to maneuver to essentially break out of our orbit with the station, so we'll get a real panoramic view. As big as the station is now, I can't really imagine how breathtaking that will be, getting to see it from every perspective. But it's a day I'm really looking forward to."
Leaving the station behind, the shuttle astronauts will use the ship's robot arm and the OBSS one final time to inspect the nose cap and wing leading edge panels to make sure no damage has been incurred since the flight day two inspection earlier in the mission.
Assuming no problems are found, the crew will spend the next day packing up for landing back at the Kennedy Space Center on April 18.
7:20 PM, 3/26/10, Update: Shuttle Discovery cleared for April 5 launch
NASA managers reviewed the shuttle Discovery's flight readiness Friday and formally cleared the ship for launch April 5 on a three-spacewalk mission to deliver ammonia coolant, supplies and science gear to the International Space Station.
Engineers plan to begin Discovery's countdown at 3 a.m. EDT on April 2, setting up a launch attempt at 6:21:22 a.m. Monday, April 5, roughly the moment Earth's rotation carries the launch pad into the plane of the space station's orbit.
Discovery's crew - commander Alan Poindexter, pilot James Dutton, flight engineer Dorothy Metcalf-Lindenburger, Stephanie Wilson, Japanese astronaut Naoko Yamazaki and spacewalkers Richard Mastracchio and Clayton Anderson - plans to fly to Florida early Thursday for final preparations.
Launch processing has proceeded smoothly, but engineers ran into a potential problem March 13 during work to load propellant into the orbital maneuvering system rocket pods on either side of Discovery's tail fin. One of two helium isolation valves in the right-side OMS pod failed in the open position.
High pressure helium, routed through regulators, is used to push propellants from storage tanks into small rocket motors used for routine orbital maneuvers. With one isolation valve stuck in the open position, engineers needed to assess whether subsequent failures could result in downstream pressurization problems with the right OMS pod.
As it turns out, one isolation valve normally is left open in orbit. If one of the downstream regulators also failed, a relief valve would prevent the high-pressure helium from damaging any of the pod's rocket thrusters. In addition, engineers concluded the pressure could be managed by actually firing the thrusters periodically.
"The helium isolation valve, the valve that's failed open, we discussed that in a lot of detail," said Bill Gerstenmaier, director of space operations at NASA headquarters. "Basically, why is it OK to fly with a valve that's essentially failed in the open position?
"The logic is simply that that valve is typically open most of the time during flight anyway, so it failed in a position that's pretty benign for us. We went through every failure case that could result in any kind of off-nominal operations. ... We went through very logically and methodically each of the conditions that could occur with this failure in the system and made sure there's no additional risk that's unacceptable."
The valve in question cannot be repaired at the launch pad. If a fix had been required, engineers would have been forced to haul Discovery back to its processing hangar for repairs, work that would have triggered a significant launch delay.
NASA is working to fly a final four shuttle flights and retire the winged spaceplanes by the end of September. Gerstenmaier said NASA could have accommodated a rollback and still launched all four missions by the end of 2010. Shuttle program manager John Shannon agreed, and said "schedule pressure" was not a factor in the decision to press ahead for launch.
"If we needed to roll back and slip we could do that, it was not a big deal to us overall," Gerstenmaier said. "But the better part of valor was to go fly, the systems are there, we understand the failure well enough that it's OK to go fly with."
Managers also discussed a potential issue with ceramic inserts around bolts that extend through shuttle heat shield tiles to secure various components to the underlying structure. During the most recent shuttle flight, one such insert around a bolt in a cockpit window frame backed out slightly. Such inserts pose an impact threat should one work free during ascent or entry.
Each shuttle is equipped with 335 such inserts but only two have ever backed all the way out in flight. Shannon said a detailed analysis indicated Discovery could be launched as is and Gerstenmaier concluded by saying "we're really ready to go fly."
The primary goals of the 131st shuttle mission are to deliver a large tank of ammonia coolant to the orbital lab complex along with a pressurized module loaded with experiment hardware, supplies, a crew sleep station and a darkroom-like housing for a large Earth-facing porthole in the U.S. Destiny lab module.
"The ammonia tank transfer is a real dance if you look at how you take the old tank off and put the new tank on," Gerstenmaier said. "That's a real ballet of hardware getting moved around on station. ... The timeline looks pretty good, pretty reasonable from an overall standpoint."
02:55 PM, 3/15/10, Update: OMS pod troubleshooting planned (UPDATED at 3:15 p.m. with payload installation delay)
Engineers plan to begin tests late this week to verify the health of helium regulator assemblies downstream from a failed isolation valve in the shuttle Discovery's right-side orbital maneuvering system rocket pod. The valve cannot be replaced or repaired at the launch pad, but if the regulators check out - and no other problems crop up - mission managers could opt to launch Discovery as is next month, relying on the system's redundancy to justify proceeding with flight.
Discovery currently is targeted for launch April 5 on a three-spacewalk space station assembly and resupply mission. If shuttle managers cannot get comfortable with a "fly-as-is" scenario, Discovery likely would have to be hauled to its hangar for removal of its right OMS pod, work that would trigger a significant launch delay.
In the meantime, NASA is pressing ahead with launch processing.
During flight, helium is used to push propellants to the OMS pod's rocket thrusters. During propellant loading overnight Friday, one of two electrically driven helium isolation valves downstream of the tank used by the right-side pod's reaction control system steering jets either failed in the open position or failed to seat, resulting in a major leak.
A schematic drawing showing the two OMS pod helium isolation valves
(circled) and downstream regulators. (Credit: NASA)
The isolation valves feed two downstream helium regulators before the two lines recombine. If the regulators work properly, the failed isolation valve would not be an issue beyond the loss of one level of redundancy. And even if subsequent failures occur, a downstream pressure relief disk would prevent the OMS pod's steering jets from being over-pressurized.
As such, the failed isolation valve is not viewed as a "safety of flight" issue, officials say. But subsequent failures could prevent Discovery's crew from completing its planned mission to the International Space Station.
Before managers can discuss possible flight rationale - NASA-speak for the justification needed to fly with a known problem - engineers must make sure the helium regulators are working normally. A full-up regulator test has not been carried out in years, officials say, because the devices have operated in near-flawless fashion. To test Discovery's, engineers first must remove test equipment from launch pad 39B and install it at pad 39A where Discovery is being processed for flight.
"The test is expected to occur late this week once a ground support equipment test panel has been calibrated," according to a NASA statement. "The helium system will be brought to flight pressure and engineers monitoring the panel will ascertain whether the regulators function properly."
Managers decided late Monday to delay moving Discovery's payload to the pad while the troubleshooting is going on. Payload delivery now is targeted for early Friday.
Discovery's crew plans to install an ammonia coolant tank on the space station's main power truss and carry up a logistics module loaded with science gear, crew equipment and needed supplies. Assuming a launch on April 5, Discovery would land back at the Kennedy Space Center on April 18.
01:35 PM, 3/13/10, Update: Engineers troubleshoot OMS pod valve problem
Engineers are troubleshooting the apparent failure of a helium isolation valve in the shuttle Discovery's right-side orbital maneuvering system rocket pod, officials said Saturday. If the problem cannot be resolved at the pad - and sources said the engineering options are limited - NASA could be forced to haul the shuttle back to its hangar for repairs, delaying a planned April 5 launch.
Managers and engineers plan to review the issue Monday and to discuss repair options as well as possible rationale to fly as is.
The two OMS pods on either side of the shuttle's tail fin house the big braking rockets used for major maneuvers and to drop the shuttle out of orbit, along with smaller reaction control system steering jets. Helium tanks provide the pressure needed to push propellants from storage tanks to the rocket thrusters.
A left-side space shuttle OMS pod during servicing. (Credit: NASA)
The isolation valve issue cropped up overnight Friday during work to load propellants into the OMS pods. Data indicated a major leak in the right OMS pod's fuel line plumbing, the apparent result of an electrically driven isolation valve failing to "seat."
The pressurization system is critical for engine operation and it features three levels of redundancy. It may be possible to develop a rationale to launch as is, but that remains to be seen.
An OMS pod being attached to a space shuttle.
(Credit: NASA)
Engineers familiar with the system said the valve cannot be directly serviced at the launch pad. If the problem cannot be resolved by indirect methods or development of an acceptable flight rationale, the only option would be to roll Discovery back to the Vehicle Assembly Building, detach it from its external tank, haul it to its processing hangar and remove the OMS pod for repairs or replacement.
Launch on a three-spacewalk space station assembly and resupply mission currently is targeted for April 5. A decision to roll Discovery back to its hangar to swap out the OMS pod would trigger a major delay. But a NASA spokesman said it was too early to tell how the issue might ultimately be resolved. In the meantime, launch processing is continuing.
01:30 PM, 3/3/10, Update: Discovery moved to launch pad
The shuttle Discovery was hauled to the launch pad Wednesday for work to ready the spaceplane for takeoff April 5 on a space station assembly mission.
Mounted atop a mobile launch platform carried by an Apollo-era crawler-transporter, Discovery began the three-and-a-half mile trip from the Vehicle Assembly Building to pad 39A at 11:58 p.m. EST Tuesday and was "hard down" at the pad by 6:48 a.m. Rollout was delayed one day because of expected bad weather from a cold front.
The shuttle Discovery, mounted atop pad 39A.
(Credit: Stephen Clark/Spaceflight Now)
Discovery's crew - commander Alan Poindexter, pilot James Dutton, flight engineer Dorothy Metcalf-Lindenburger, Stephanie Wilson, Japanese astronaut Naoko Yamazaki and spacewalkers Richard Mastracchio and Clayton Anderson - flew to Florida Monday to review emergency procedures and to participate in a practice countdown Friday.
"We're really looking forward to our dress rehearsal for launch, our TCDT here this week," Poindexter said when the crew arrived. "We've been training real hard and we're just real proud of the folks down here and all the hard work they did getting OV-103 (Discovery) ready for flight."
Shuttle program managers plan to review launch processing March 10 and 11, followed by an executive-level flight readiness review March 26 to set an official launch date. As of this writing, launch of the 131st shuttle mission is targeted for 6:21:16 a.m. on April 5.
Launch originally was targeted for March 18, but the flight was pushed back because of cold weather in Florida that delayed processing and to avoid conflict with a Russian Soyuz mission scheduled for launch April 2. As a result of the delay, the launch moved from daylight to pre-dawn darkness, providing at least one more night launch as the shuttle program winds down toward retirement.
The primary goals of Discovery's mission are to deliver science gear, supplies and equipment to the International Space Station, including a new crew sleep station and a lab freezer. Three spacewalks are planned to retrieve a Japanese experiment, to replace a gyroscope system and to install a fresh ammonia tank assembly for the lab's coolant system.
Assuming an on-time launch, Poindexter will guide Discovery to a docking at the forward port of the International Space Station around 3:50 a.m. on April 7. The first spacewalk is scheduled to begin around 12:11 a.m. April 9 with additional overnight excursions planned for April 10-11 and April 12-13. Undocking from the station is expected around 8:26 p.m. on April 15, with landing back at the Kennedy Space Center around 12:35 a.m. on April 18.
NASA's final three shuttle missions are targeted for launch May 14, July 29 and Sept. 16, although one or more of those flights may be rescheduled based on payload processing and space station operations.
10:45 PM, 2/21/10, Update: Shuttle Endeavour lands in Florida (UPDATED at 1:50 a.m. with crew comments)
The shuttle Endeavour dropped through a partly cloudy sky and glided to a ghostly night landing at the Kennedy Space Center Sunday, leaving the International Space Station behind with a new life support module and observation deck.
Approaching the spaceport in a steep dive, commander George Zamka guided the shuttle through a sweeping left overhead turn, lined up on runway 15 and swooped to a picture-perfect touchdown at 10:20:31 p.m. EST. Pilot Terry Virts then released a red-and-white braking parachute and a few moments later, the spaceplane rolled to a stop.
"Houston, Endeavour, wheels stopped," Zamka radioed in a tradition call to mission control.
"Roger wheels stopped, Endeavour. Welcome home," replied astronaut Rick Sturckow from Houston. "Congratulations to you and the crew on an outstanding mission, installing the Tranquility node and opening up the cupola's windows to the world."
"Well Houston, it's great to be home," Zamka said. "It was a great adventure."
Space station flight engineer Soichi Noguchi watched Endeavour's fiery re-entry from a window in the new cupola observation deck, tweeting via the internet "I watched the shuttle atmospheric reentry from Cupola window. The view was definitely out-of-the-world."
The shuttle Endeavour touches down at the Kennedy Space
Center. (Photo: NASA TV)
Exhaust from the shuttle's hydraulic power units shoots
into the night sky as Endeavour rolls down the runway.
(Photo: NASA TV)
Mission duration was 13 days 18 hours six minutes and 24 seconds, covering 217 complete orbits and 5.6 million miles since blastoff Feb. 8 from nearby pad 39A.
Zamka, Virts, Kathryn Hire, flight engineer Stephen Robinson and spacewalkers Robert Behnken and Nicholas Patrick doffed their pressure suits for a traditional runway inspection before heading to crew quarters for reunions with friends and family.
"STS-130 is mission complete, we're safe on deck here at Kennedy Space Center and that's due to the work of a lot of people," Zamka said. "We had a great team, we had tremendous hardware to bring up - node 3 was pristine, cupola was beautiful ... and Endeavour, my goodness, what a machine! She was perfect throughout the flight and we brought her back safe and sound due to a great mission control team. So thanks to all who were involved."
The shuttle Endeavour, banking during re-entry, as photographed
by flight engineer Soichi Noguchi from the cupola. (Photo: NASA TV)
Landing was in doubt earlier in the day as entry Flight Director Norm Knight assessed cloudy weather at the Kennedy Space Center.
But conditions improved as the night wore on and based on observations by astronaut Christopher Ferguson, flying a shuttle training jet near the runway, Knight cleared Zamka and Virts to fire Endeavour's braking rockets on time at 9:14 p.m. to begin the descent. Zamka had no problems and touchdown was uneventful.
Endeavour undocked from the space station Friday night, leaving the outpost more than 98 percent complete with the addition of the Tranquility habitation module and a seven-window cupola observation deck.
The station's total pressurized volume is now 28,947 cubic feet - roughly the same as a 747 jumbo jet - and a habitable volume of 12,420 cubic feet. Total mass now stands at a bit more than 799,000 pounds. When the shuttle is attached, the two spacecraft mass more than a million pounds.
Pilot Terry Virts, left, and commander George Zamka on
Endeavour's flight deck after landing. (Photo: NASA TV)
The shuttle Endeavour surrounded by support crews. (Photo: NASA TV)
The Endeavour astronauts pose on the runway. (Photo: NASA TV)
The station's U.S. life support equipment - an oxygen generator, carbon dioxide scrubber, a water processing rack, a urine recycling rack and a toilet - were moved into Tranquility after it was attached to the station, along with a high tech exercise machine.
The cupola, launched on the outboard end of Tranquility, was moved to its Earth-facing port for use as an observation station and robot arm work station.
Only four more shuttle flights are planned to deliver supplies, equipment, experiment racks and other gear in a final push to leave the lab complex in the best possible shape when the shuttle fleet is retired this fall. And with every successful launch and landing, the reality of the looming end of the shuttle program gains more traction among the men and women who maintain the iconic orbiters.
"I got to watch a lot of the folks out on the runway tonight just kind of stand there and look up at Endeavour and think about the majesty of that ship and its next to last flight," said Launch Director Mike Leinbach. "There's a whole series of 'lasts' coming up. The people fall in love with the machines. It's going to be hard to let them go. But we've been given our direction. We're mature about it, we're professional about it so we're going to process and fly that last mission. And move on."
With Endeavour back on the ground, engineers at the Kennedy Space Center plan to haul the shuttle Discovery from its processing hangar to the Vehicle Assembly Building Tuesday for attachment to an external tank and solid fuel boosters. If all goes well, Discovery will be hauled to pad 39A on March 2, setting the stage for launch April 5.
On March 18, the Russian Soyuz TMA-16 capsule is scheduled to undock from the station, bringing Expedition 22 commander Jeffrey Williams and cosmonaut Maxim Suraev back to Earth after six months in orbit.
Another Soyuz, TMA-18, is scheduled for launch from the Baikonur Cosmodrome in Kazakhstan on April 2 to carry three fresh crew members to the outpost: Alexander Skvortsov, Mikhail Kornienko and NASA astronaut Tracy Caldwell.
Discovery is scheduled for take off three days later to deliver new science racks, a replacement ammonia coolant tank assembly, a rate gyroscope and to retrieve a Japanese experiment package.