Weather Outlook Improves for Thursday Shuttle Launch

CAPE CANAVERAL, Fla - The weather outlook has improved slightly for this week?s planned launch of the shuttle Atlantis and a European lab to the International Space Station (ISS), NASA officials said Tuesday.

Atlantis and its seven-astronaut crew now have a 90 percent chance of favorable weather conditions for their Thursday afternoon launch toward the ISS, with top shuttle officials discussing plans for the upcoming space shot here at NASA?s Kennedy Space Center (KSC).

?We are optimistic about the weather on Thursday,? said shuttle weather officer Kathy Winters, of the U.S. Air Force?s 45^th Weather Squadron, in a morning status briefing.

Winters said the possibility of a low cloud layer thwarting Thursday?s planned 4:31 p.m. EST (2131 GMT) liftoff from Launch Pad 39A dropped slightly, which allowed Atlantis? flight chances to improve by 10 percent.

Commanded by veteran shuttle flyer Stephen Frick, Atlantis? STS-122 astronauts will deliver the European Space Agency?s Columbus laboratory to the ISS, swap out one member of the station?s Expedition 16 crew and stage three spacewalks to upgrade the outpost with new hardware and experiments during their planned 11-day mission.

Later today, shuttle engineers will load Atlantis with the super-chilled liquid hydrogen and liquid oxygen used to power the orbiter?s three fuel cells during its space station construction flight.

Top shuttle officials are also holding their traditional Launch Readiness Review today to determine whether the orbiter is indeed ready for liftoff. They will announce their decision during a press briefing to begin no earlier than 4:00 p.m. EST (2100 GMT).

?At this point, I?m happy to report that we have no issues whatsoever,? NASA test director Steve Payne told reporters today. ?The countdown is going nicely and the flight crew is ready to go and eager for Thursday?s launch.?

Engineers completed last-minute repairs to three minor dings near the top of Atlantis? foam-covered fuel tank Monday afternoon, he added.

?They turned out well,? Payne said, adding that the repairs have already been approved for flight. ?They were so slight that it took a really close inspection to detect them in the first place.?

NASA has a slim launch window that closes Dec. 13 in which to launch Atlantis while the angles between the space station?s solar arrays and the sun are favorable to support docked operations. The agency is prepared to make four launch attempts in five days before standing down to top off Atlantis? liquid hydrogen and oxygen supply, Payne said.

If the shuttle launches early in its window and its power supplies hold out, NASA could extend the STS-122 mission two extra days and add a fourth spacewalk to inspect a balky ISS solar array joint.

?Obviously, we want to have a good load and launch as early as possible,? Payne said. ?Thursday is our goal.?

NASA will broadcast Atlantis' STS-122 mission live on NASA TV. Click here for SPACE.com's shuttle mission coverage and NASA TV feed.

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