ISS Fan Club

Wed, 08 Jul 2009 09:36:41 AM CDT

The countdown to liftoff of space shuttle Endeavour on its STS-127 mission will officially begin tonight at 10 p.m. EDT when clocks begin ticking backward from T-43 hours.

Endeavour's seven astronauts arrived at NASA's Kennedy Space Center on Tuesday afternoon and are making their final preparations for launch, scheduled for July 11 at 7:39 p.m.

"At this point, I'm happy to report we are ready to proceed with the launch countdown," NASA Test Director Charlie Blackwell-Thompson said Wednesday morning during a countdown status briefing at Kennedy. "We're ready to (fuel) this vehicle on Saturday morning and proceed with our launch on Saturday evening."

Weather is a concern for launch, according to Shuttle Weather Officer Kathy Winters. Due to the threat of thunderstorms, officials believe there is a 40 percent chance weather would cooperate for Saturday's liftoff.

Source http://www.nasa.gov/mission_pages/shuttle/main/index.html