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A final spacewalk, undocking and return to Earth BY WILLIAM HARWOOD STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION Posted: March 10, 2008 The Japanese Experiment Module was designed before th Columbia disaster and before NASA built the heat shield inspection boom that now is a standard fixture on the right side of the shuttle's cargo bay. The JEM is so large, the orbiter boom sensor system cannot be carried by Discovery when the big module is launched in late May. To make sure that crew has the ability to inspect their tiles and wing leading edge panels, Endeavour's boom will be left behind on the space station. Because of that, Endeavour's crew will not be able to conduct a post-undocking inspection to look for signs of damage from space debris or micrometeoroids. As a result, they plan to use the boom on the day between the fourth and fifth spacewalks to carry out what would normally be termed a late inspection.
DATE/EDT.......DD...HH...MM...EVENT 03/21/08 Fri 01:28 PM...10...11...00...Crew wakeup Fri 04:03 PM...10...13...35...OBSS starboard wing survey Fri 05:28 PM...10...15...00...Experiment rack 3 transfer Fri 06:33 PM...10...16...05...Crew meals begin Fri 06:43 PM...10...16...15...LDRI downlink Fri 07:43 PM...10...17...15...OBSS nose cap survey Fri 07:43 PM...10...17...15...OBSS KAU assembly Fri 09:13 PM...10...18...45...OBSS port wing survey Fri 10:23 PM...10...19...55...EVA-5: Tool config Fri 11:13 PM...10...20...45...LDRI downlink Fri 11:18 PM...10...20...50...Airlock prep 03/22/08 Sat 12:58 AM...10...22...30...EVA-5: Procedures review Sat 03:33 AM...11...01...05...EVA-5: Airlock depress to 10.2 psi Sat 04:28 AM...11...02...00...STS crew sleep beginsThe next day, Behnken and Foreman will venture back outside for a fifth and final spacewalk to mount the OBSS on the forward face of the station's power truss. Electrical connections will provide power for heaters needed to keep the boom's laser sensor and camera package from getting too cold. "That sensor boom is going to be left on station because the following mission is going to deliver the next portion of the Japanese laboratory," Behnken said. "That module is a very large module and there's actually not room in the shuttle payload bay to launch both that module and this sensor boom on the same shuttle flight. So to provide the inspection capability to allow that next shuttle mission to be able to inspect their thermal protection system before they come back for re-entry, they're going to need to have a sensor boom. They can't bring their own and so our flight is going to do an inspection late in the mission and then we'll stow the boom during our EVA 5 on the ISS and hook up the power to it and it'll be all ready for those guys when they actually arrive and install the Japanese module." While the spacewalkers are setting up their tools and running a 30-foot-long power cord down the truss, the shuttle's robot arm will hand the sensor boom to the station arm. As soon as possible, Behnken will plug the power cable into the boom to activate the heaters. The arm then will release the boom so Behnken and Foreman can bolt it in place. With the OBSS mounted on the station, Behnken and Foreman will turn their attention to the station's right side solar alpha rotary joint, or SARJ, a massive 10-foot-wide motor-driven gear system that turns outboard solar arrays like a giant paddle wheel to keep them face on to the sun. Last fall, engineers because concerned about high vibration levels and power usage and ordered an inspection. To their dismay, spacewalking astronauts reported metal shavings covering the interior of the bearing race ring and damage to the ring itself. Engineers are still not sure what is causing the damage, and the joint is locked down pending additional analysis. Engineers are considering a plan to remove 12 bearing assemblies and move them to an identical race ring that is available as a backup. But the work would require multiple spacewalks and flight planners don't want to take that step until they have a better idea of what might be wrong. Behnken and Foreman will replace a bearing assembly that was removed during an earlier spacewalk and returned to Earth for analysis. They also plan to carry out additional inspections to help engineers collect more data on the contaiminated race ring's current condition. Finally, to pave the way for attachment of the JEM module, the astronauts will remove launch locks on the Harmony module's left-side and downward-facing ports.
DATE/EDT.......DD...HH...MM...EVENT 03/22/08 Sat 12:28 PM...11...10...00...Crew wakeup Sat 01:08 PM...11...10...40...EVA-5: 14.7 psi repress/hygiene break Sat 01:58 PM...11...11...30...EVA-5: Airlock depress to 10.2 psi Sat 02:28 PM...11...12...00...EVA-5: Campout EVA preps Sat 02:28 PM...11...12...00...SSRMS EVA-5 setup Sat 03:48 PM...11...13...20...EVA-5: Spacesuit purge Sat 04:03 PM...11...13...35...EVA-5: Spacesuit prebreathe Sat 04:53 PM...11...14...25...EVA-5: Crew lock depressurization Sat 05:23 PM...11...14...55...EVA-5: Spacesuits to battery power Sat 05:28 PM...11...15...00...EVA-5: Airlock egress Sat 05:33 PM...11...15...05...SSRMS grapples OBSS Sat 05:48 PM...11...15...20...EVA-5: Setup Sat 06:03 PM...11...15...35...SRMS releases OBSS Sat 06:08 PM...11...15...40...EVA-5: OBSS power cable install Sat 06:18 PM...11...15...50...OBSS handoff to EVA Sat 07:28 PM...11...17...00...Crew meals begin Sat 07:43 PM...11...17...15...EVA-5: OBSS stow Sat 08:58 PM...11...18...30...EVA-5: Trundle bearing assembly No. 5 install Sat 10:13 PM...11...19...45...EVA-5 (EV1): JLP trunnion covers Sat 10:13 PM...11...19...45...EVA-5 (EV2): Harmony port and nadir launch locks Sat 11:08 PM...11...20...40...EVA-5: Cleanup Sat 11:33 PM...11...21...05...EVA-5 Airlock ingress Sat 11:53 PM...11...21...25...EVA-5: Airlock repressurization 03/23/08 Sun 12:28 AM...11...22...00...SRMS powerdown Sun 03:58 AM...12...01...30...ISS crew sleep begins Sun 04:28 AM...12...02...00...STS crew sleep beginsThe day after the fifth and final spacewalk, the astronauts will hold a joint crew news conference and begin moving spacesuits and other equipment from the station to the shuttle for return to Earth. Undocking is planned the day after that, around 7:55 p.m. on March 24. As usual with shuttle departures, pilot Johnson will be at the controls for a lap-and-a-quarter fly-around. "That's going to be a great thing for a pilot," he told CBS News. "Undocking is about the opposite of docking, you're leaving the space station at a pretty controlled rate. And then at the end of the undocking timeline, when we get about 300 to 400 feet away, then we start what's called a fly-around and that's where you take the orbiter and go 360 degrees all the way around the station, about 45 minutes of flying. You get to see angles of space station that aren't normally observed and just a great, exciting period for the whole crew." Here is the timeline for the remainder of Endeavour's mission:
DATE/EDT.......DD...HH...MM...EVENT 03/23/08 Sun 12:28 PM...12...10...00...Crew wakeup Sun 01:58 PM...12...11...30...Crews off duty Sun 07:03 PM...12...16...35...ISS crew meal Sun 08:18 PM...12...17...50...STS crew meal Sun 09:23 PM...12...18...55...EVA prep for transfer to shuttle Sun 10:48 PM...12...20...20...Rendezvous tools checkout Sun 11:58 PM...12...21...30...Joint crew photo 03/24/08 Mon 12:18 AM...12...21...50...Joint crew news conference Mon 03:28 AM...13...01...00...ISS crew sleep begins Mon 03:58 AM...13...01...30...STS crew sleep begins Mon 11:58 AM...13...09...30...Crew wakeup Mon 04:13 PM...13...13...45...Oxygen system teardown Mon 04:58 PM...13...14...30...Farewell ceremony Mon 05:13 PM...13...14...45...Hatch closure Mon 05:18 PM...13...14...50...Group B computer powerup Mon 05:43 PM...13...15...15...Leak checks Mon 06:28 PM...13...16...00...Centerline camera setup Mon 06:58 PM...13...16...30...Undocking timeline begins Mon 07:55 PM...13...17...27...UNDOCKING Mon 09:10 PM...13...18...42...Separation burn No. 1 Mon 09:23 PM...13...18...55...PMA-2 depressurization Mon 09:28 PM...13...19...00...Post undocking computer reconfig Mon 09:38 PM...13...19...10...Separation burn No. 2 Mon 09:53 PM...13...19...25...SRMS powerdown Mon 10:13 PM...13...19...45...Group B computer powerdown Mon 10:28 PM...13...20...00...Spacesuit install Mon 10:58 PM...13...20...30...EVA unpack and stow Mon 11:03 PM...13...20...35...Undocking video replay 03/25/08 Tue 03:28 AM...14...01...00...Crew sleep begins Tue 11:28 AM...14...09...00...Crew wakeup Tue 02:28 PM...14...12...00...Cabin stow begins Tue 03:13 PM...14...12...45...FCS checkout Tue 04:23 PM...14...13...55...RCS hotfire Tue 04:38 PM...14...14...10...PILOT operations Tue 06:48 PM...14...16...20...Crew meals begin Tue 07:13 PM...14...16...45...Orbit adjust rocket firing Tue 08:33 PM...14...18...05...PAO event Tue 08:53 PM...14...18...25...Cabin stow resumes Tue 10:03 PM...14...19...35...Entry video setup Tue 10:28 PM...14...20...00...Launch/entry suit checkout Tue 11:28 PM...14...21...00...Recumbent seat setup Tue 11:38 PM...14...21...10...Wing leading edge sensors deactivated Tue 11:58 PM...14...21...30...Laptop computer teardown (part 1) 03/26/08 Wed 12:28 AM...14...22...00...Deorbit review Wed 03:28 AM...15...01...00...Crew sleep begins Wed 11:28 AM...15...09...00...Crew wakeup Wed 02:13 PM...15...11...45...Group B computer powerup Wed 02:28 PM...15...12...00...IMU alignment Wed 03:18 PM...15...12...50...Deorbit timeline begins Wed 07:31 PM...15...17...03...Deorbit ignition (rev. 249) Wed 08:33 PM...15...18...05...Landing
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