CAPECANAVERAL, Fla. - NASA?s shuttle Atlantis and a massive European laboratory areon track for their planned Thursday launch toward the International SpaceStation (ISS).
Atlantis?seven-astronaut crew is slatedto liftoff from a seaside launch pad here at NASA?s Kennedy Space Center(KSC) spaceport at 4:31 p.m. EST (2131 GMT), with a 90 percent chance of pristineweather conditions.
?Thevehicle is looking good and the weather is looking good, too,? said shuttleweather officer Kathy Winters, of the U.S. Air Force?s 45th Weather Squadron,in a morning briefing.
Commandedby veteranshuttle astronaut Stephen Frick, Atlantis? STS-122 crew will haul theEuropean Space Agency?s (ESA) 13-ton Columbus lab to the ISS during a planned 11-daymission. Three spacewalks are on tap for the spaceflight, but NASA mayextend the mission by two days to add fourth excursion to inspect a balky ISSsolar array joint.
NASA testdirector Jeff Spaulding said shuttle workers detected a small leak in groundequipment late Wednesday after loading super-chilled liquid hydrogen into Atlantis?tanks, but the glitch is not expected to hinder plans for tomorrow?s launch.
?It?s onthe ground side only,? Spaulding told reporters. ?It is not a vehicle issue atall.?
NASA spaceshuttles use liquid hydrogen and liquid oxygen reactants to power their threefuel cells during orbital flight.
Spauldingsaid engineers will spend the bulk of today testing Atlantis? communication systemsand loading the final pieces of cargo into the shuttle?s middeck. A pair ofexperiments and some last-minute food items are on that list, he said.
Frick and hisSTS-122 crew, meanwhile, plan to visit Atlantis at the pad today as part ofthe prelaunch preparations, NASA officials said.
At 8:00p.m. EST (0100 Dec. 6 GMT) tonight, pad workers are expected to retract theshroud-like Rotating Service Structure that protects Atlantis from weather atits Pad 39A launch site.
NASA has aslim window that closes on Dec. 13 in order to launch Atlantis to the ISS whilethe angles between the station?s solar arrays and the sun are favorable for dockedoperations. If weather foils Thursday?s launch attempt, NASA could try again asearly as Friday at 4:09 p.m. EST (2109 GMT).
Winterssaid the weather outlook offers an 80 percent change of favorable launchconditions on Friday, but will dip to about 60 percent on Saturday.
Atlantis?STS-122 mission will mark NASA?s fourth shuttle flight of the year and thesecond to deliver a new pressurized module to the ISS.
NASAwill broadcast Atlantis' STS-122 mission live on NASA TV. Click here for SPACE.com's shuttle mission coverage and NASATV feed.
- SPACE.com Video Interplayer: NASA's STS-122: Columbus Sets Sail for ISS
- IMAGES: Discovery's STS-120 Mission in Pictures
- VIDEO: ISS Commander Peggy Whitson Takes Charge
