Weather 60 percent "no go"; Crew to arrive

A frontal system could delay Atlantis' launch by at least 24 hours.

The frontal boundary could sit over the launch site on Thursday, when a 2:45 p.m. launch is scheduled, shuttle weather officer Kathy Winters said. However, she added that the exact time the front will pass over the launch pad was undetermined.

"It's going to be somewhere over Central Florida on Thursday," said Winters at a morning countdown status briefing.

Rain, clouds and lightning from the front could pose a danger that would delay the launch on Thursday. However, forecasts show an 80 percent chance of favorable launch weather on Friday.

On an 11-day mission with three spacewalks scheduled, Atlantis is being prepared for launch on a trip to the International Space Station. With a connector that caused intermittent signals replaced and a kinked Freon hose straightened, engineers are tracking no issues before launch.

Watch The Flame Trench for coverage of crew arrival at 10:30 a.m. Countdown begins at 5 p.m.

STS-122 Fact Sheet

Air Force weather forecast

Atlantis' commander, Stephen Frick, and pilot, Alan Poindexter, are a pair of steady former U.S. Navy fighter pilots, with more than 800 carrier landings between them. The mission specialists include Leland Melvin, a research scientist and former wide receiver drafted by the NFL in 1986; Rex Walheim, an Air Force colonel and experienced spacewalker; Hans Schlegel, a German physicist who flew on a shuttle mission 15 years ago; Stanley Love, an astronomer; and Leopold Eyharts, a French fighter pilot who will remain at the space station in place of U.S. flight engineer Dan Tani.

NASA plans 10 to 12 more shuttle flights before the program stops flying in 2010. The agency tenatively plans to retire Atlantis after an August mission to repair the Hubble Space Telescope.