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Crew tests re-entry systems, pack for Wednesday landing BY WILLIAM HARWOOD STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION Posted: November 6, 2007 The Discovery astronauts worked through a busy final day in space today, packing up and testing the shuttle's re-entry systems for landing Wednesday at the Kennedy Space Center. Commander Pam Melroy, pilot George Zamka and flight engineer Stephanie Wilson fired up one of Discovery's three hydraulic power units around 5:45 a.m. as part of a flight control system checkout. Using a laptop flight simulator, Melroy and Zamka planned to practice landing procedures later in the day. The astronauts also will set up a recumbent seat on the shuttle's lower deck for returning space station astronaut Clay Anderson. He will make the trip back to Earth resting on his back to ease his re-adaptation to gravity after 152 days in space. In a morning message to the crew, NASA's Mission Management Team said the forecast for landing Wednesday was favorable, with generally clear skies and a brisk headwind for two back-to-back deorbit opportunities. As a result, NASA managers do not plan to activate backup landing sites in California and New Mexico. If the weather or some other problem prevents a Florida landing Wednesday, the astronauts will remain in orbit an additional day and try again Thursday. In that case, Lunney might opt to activate Edwards Air Force Base, Calif., depending on the weather in Florida. If landing is delayed to Friday, Kennedy, Edwards and Northrup Strip, N.M., will be activated. "The limiting orbiter consumable will be supply water with at least 7 deorbit opportunities available over 3 days," the MMT told the astronauts. "The remaining orbiter consumables will support EOM (end of mission) +3 (days) with at least 2 opportunities per day. "The plan is to target two KSC opportunities for EOM on orbits 238 and 239. In the event of an EOM wave-off, EDW may be considered on EOM+1 pending the latest weather forecast and all three sites (KSC, EDW, NOR) will be activated on EOM+2." Passing just off the east coast Monday, Melroy reported clear skies as cameras on the shuttle beamed down spectacular views of the entire Florida peninsula. "Well, we could see the runway from orbit," she said. "So we're thinking the weather there is looking pretty good!" The MMT told the crew a dry front "will pass through KSC early Wednesday morning. This front is forecast to leave behind dry, cool air and a GO forecast with a head wind of (14 knots peaking to 23) on KSC runway 33. EOM+1 has a GO forecast for EDW and NOR while KSC has a chance of precipitation and a chance of ceilings. EOM+2 has a GO forecast for KSC and NOR while EDW has a slight chance for virga (precipitation that doesn't reach the ground)." Discovery's original flight plan called for a pre-dawn entry and a so-called ascending node approach from southwest to northeast that would carry the shuttle across Central America, the Caribbean and then into Florida. Ascending node entries require slightly less propellant than descending node, northwest-to-southeast approaches across the heartland of America. Descending node trajectories also avoid high-altitude, high-latitude clouds of ice crystals that can form in summer months over the Northern Hemisphere. But Discovery's mission was extended to cope with space station problems and NASA managers ultimately decided to switch to a descending node entry, one that will carry Discovery across the central United States for the first time since the 2003 Columbia disaster. Shuttle Program Manager Wayne Hale said Monday that noctilucent clouds don't tend to form at this time of the year and given Discovery has plenty of propellant, "we opted for a descending rev deorbit this time, which allows us to land in the daytime." "It's a basic fact that landing in the daylight is a safer and easier task than landing in the dark," he said. "And the commander on this flight has definitely expressed a preference for daylight landing." In the wake of the Columbia disaster, NASA assessed the risk to the public posed by a returning shuttle that might suffer a catastrophic breakup. "We have a standard public safety risk which is always computed and for an undamaged orbiter, this constitutes a very minimal ... risk to fly over the middle of the United States," Hale said. "The primary reason we're doing it is to allow us to have a daylight landing." All shuttle pilots are trained to handle landing in daylight or darkness, but "I think most pilots prefer daylight landings," Hale said. "I don't think this is a really strong impetus from the commander, but it is her preference. "More than that, we are approaching a very long mission here,' he said. "This will be the longest mission, I believe, by about 24, 26 hours, longer than any mission to the international space station and any mission other than a few we flew in the early 90s with what we called the extended duration orbiter pallet. We flew couple of very long missions with the EDO pallet. "So this is becoming a long mission and we want to make sure we set up the commander for the very best landing conditions that we possibly can." Entry flight director Bryan Lunney will provide entry details at a 2:30 p.m. briefing. In the meantime, here is an updated timeline of today's activity and a look ahead to Wednesday (in EST and mission elapsed time; includes revision R of the NASA television schedule): DAY/EST.........DD...HH...MM...EVENT 11/06/07 Tue 02:38 AM...13...16...00...Crew wakeup Tue 05:23 AM...13...18...45...Flight control system checkout Tue 05:38 AM...13...19...00...Cabin stow Tue 06:33 AM...13...19...55...Maneuvering thruster test firing Tue 08:18 AM...13...21...40...Wing leading edge sensors deactivated Tue 09:43 AM...13...23...05...News media interviews Tue 10:03 AM...13...23...25...Crew meal Tue 11:03 AM...14...00...25...Deorbit review Tue 11:33 AM...14...00...55...Entry video setup Tue 12:00 PM...04...01...22...Space station status briefing on NASA TV Tue 01:48 PM...14...03...10...Ergometer stow Tue 02:18 PM...14...03...40...Recumbent seat setup Tue 02:30 PM...14...03...52...Mission status briefing on NASA TV Tue 02:48 PM...14...04...10...Launch/entry suit checkout Tue 02:54 PM...14...04...16...Orbit adjustment rocket firing Tue 03:03 PM...14...04...25...PILOT landing practice Tue 04:03 PM...14...05...25...KU-band antenna stow Tue 04:03 PM...14...05...25...Laptop network teardown Tue 06:08 PM...14...07...30...Crew sleep begins Tue 07:00 PM...14...08...22...Daily video highlights reel on NASA TV 11/07/07 Wed 02:38 AM...14...16...00...Crew wakeup Wed 05:43 AM...14...19...05...GIRA stow; OCAC stow Wed 06:58 AM...14...20...20...Group B computer powerup Wed 07:18 AM...14...20...40...IMU alignment Wed 08:03 AM...14...21...25...Deorbit timeline begins Wed 11:59 AM...15...01...21...1st deorbit opportunity (rev. 238) Wed 01:01 PM...15...02...23...1st KSC landing opportunity Wed 01:38 PM...15...03...00...2nd deorbit opportunity (rev. 239) Wed 02:36 PM...15...03...58...2nd KSC landing opportunity BACKUP LANDING OPPORTUNITIES (preliminary estimates) 11/08/07 Thu 10:33 AM...15...23...55...Deorbit to KSC............Orbit 253 Thu 11:33 AM...16...00...55...Landing at KSC Thu 11:58 AM...16...01...20...Deorbit to Edwards........254 Thu 01:00 PM...16...02...22...Landing at Edwards Thu 12:01 PM...16...01...23...Deorbit to Northrup.......254 Thu 01:03 PM...16...02...25...Landing at Northrup Thu 12:09 PM...16...01...31...Deorbit to KSC............254 Thu 01:08 PM...16...02...30...Landing at KSC Thu 01:34 PM...16...02...56...Deorbit to Edwards........255 Thu 02:35 PM...16...03...57...Landing at Edwards Thu 01:37 PM...16...02...59...Deorbit to Northrup.......255 Thu 02:37 PM...16...03...59...Landing at Northrup Thu 03:09 PM...16...04...31...Deorbit to Edwards........256 Thu 04:08 PM...16...05...30...Landing at Edwards 11/09/07 Fri 10:39 AM...17...00...01...Deorbit to KSC............269 Fri 11:39 AM...17...01...01...Landing at KSC Fri 12:04 PM...17...01...26...Deorbit to Edwards........270 Fri 01:06 PM...17...02...28...Landing at Edwards Fri 12:08 PM...17...01...30...Deorbit to Northrup.......270 Fri 01:09 PM...17...02...31...Landing at Northrup Fri 12:15 PM...17...01...37...Deorbit to KSC............270 Fri 01:13 PM...17...02...35...Landing at KSC Fri 01:40 PM...17...03...02...Deorbit to Edwards........271 Fri 02:40 PM...17...04...02...Landing at Edwards Fri 01:43 PM...17...03...05...Deorbit to Northrup.......271 Fri 02:42 PM...17...04...04...Landing at Northrup
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