Countdown Continues Toward Friday's Launch of STS-135

The countdown for the final space shuttle launch began yesterday at 1 p.m. EDT, starting at the T-43 hour mark. However, the weather forecast looks less than favorable for Friday's launch, with only a 30 percent chance of a "go" at the 11:26 a.m. liftoff time. 

At the 10 a.m. precountdown status briefing yesterday, NASA Test Director Jeremy Graeber reported space shuttle Atlantis is ready for flight, and STS-135 payload manager Joe Delai said the payloads are ready to go as well. The only issue standing in the way of liftoff is the chance of showers and thunderstorms developing along the sea-breeze front reported by Kathy Winters, shuttle weather officer.

Today's prelaunch news conference will begin at 11:30 a.m. EDT live on NASA TV. Participants will be Mike Moses, Mission Management Team chair and space shuttle launch integration manager, Mike Leinbach, shuttle launch director, and Kathy Winters, shuttle weather officer.