Thisstory was updated at 12:33 p.m. EDT.
CAPECANAVERAL, Fla. - Astronauts aboard NASA?s shuttle Discovery are gearing up fortheir planned Saturday landing after Mission Control found that a lost metalclip poses no threat to their spacecraft?s return.
Shuttlecommander MarkKelly and pilot Kenneth Ham test fired Discovery?s maneuvering thrusters andpower up systems to flex the shuttle?s flight control surfaces. But after thosetests, they reported spotting a shiny, rectangular bit of debris drifting awayshuttle to the aft of its starboard wing.
Missioncontrollers swiftly studied the 1- to- 1 1/2-foot long (0.3-0.4 meter) objectin short video of and still images captured by the shuttle crew. It was one ofthree tail-mounted metal clips that are not needed for landing and posed nothreat to the orbiter?s planned landing.
?We?ve seenthese things come off before and it?s really not a concern at all for entry,? Kellysaid in a televised interview today. ?It?s no worry at all.?
Discovery?screw is stowing last bits of cargo to prepare for tomorrow?s planned 11:15 a.m.EDT (1515 GMT) landing here at NASA?s Kennedy Space Center. Kelly and Ham arealso rehearsing landing activities via a computer simulation.
?Overall,it?s a get ready for entry day,? NASA?s deputy shuttle program manager LeRoyCain said Thursday, adding that the orbiter?s heat shield appeared to be ingood health for landing.
Saturdayhomecoming ahead
Discovery?ssix-man, one-woman crew is returning to Earth after a two-week mission todeliver Japan?s massive, billion-dollarKibo laboratory to the International Space Station (ISS).
?That waspretty much solid work,? Ham said Thursday. ?We?re all pretty much tired atthis point and getting ready to come home.?
Japan?s37-foot (11-meter) laboratory is the size of a tour bus and the second segmentof the Kibo research facility to reach orbit. It followed its small storageroom, which astronauts delivered during an earlier mission in March.
The newroom, the largest ever launched to the space station, includes two windows, arobotic arm and a small airlock for passing new experiments to a plannedporch-like platform due to launch to the space station next year. A smallerrobotic arm for fine movements is also slated to fly.
?It wasjust amazing,? said Discovery mission specialist Akihiko Hoshide, who helpedinstall Kibo, of the view of his country?s new space lab duringundocking Wednesday. ?I can?t really explain it.?
Returningto Earth with Kelly, Ham and Hoshide are mission specialists Karen Nyberg,Ronald Garan, Michael Fossum and returning station crewmember Garrett Reisman,who said he was awed at the sheer size of the now nearly three-quarterscomplete space station when Discovery undocked.
?It startedout as just a single, little module, and now it?s enormous,? said Reisman, whois wrapping up a three-month spaceflight aboard the station and has comparedits interior to the inside of a jumbo jet. ?With the addition of Kibo, it lookslike a real space station, and that?s exciting.?
Reisman, aNASA astronaut, joined the station?s crew in March and was replaced by fellowU.S. spaceflyer Gregory Chamitoff, who arrived aboard Discovery last week to beginhis own six-month mission.
Discovery astronautswill set up a special recumbent seat for Reisman today on the shuttle?s middeckthat will allow the returning long-duration spaceflyer to return to Earth?sgravity in a reclining position, rather than the upright seats of the shuttle?sshort-term flyers.
?The truthis, adjusting back to gravity is not so easy,? Reisman said during the mission.?Just like adjusting to weightlessness takes some time, adjusting back togravity takes some time too.?
Discoveryhas two chances to land Saturday with NASA?s Spaceflight Meteorology Group atthe Johnson Space Center in Houston forecasting relatively fair conditions onlanding day. Some clouds are expected during the shuttle?s first landingwindow, with a slight chance of rain showers within 30 miles (48 km) during asecond opportunity at 12:50 p.m. EDT (1650 GMT).
MissionControl roused Discovery?s crew early Friday with the song ?Baby Won?t YouPlease Come Home? by Louis Prima and Keely Smith, a tune chosen for Reisman byhis wife Simone.
?Goodmorning to you Houston and a special good morning to Simone, my favoriteEarthling,? Reisman said. ?Get ready doll face, Discovery?s coming home.?
NASA isbroadcasting the Discovery's STS-124 mission live on NASA TV. Click here for SPACE.com'sshuttle mission updates and NASA TV feed.
