NASA workers walk along a platform on the service structure next to space Shuttle Discovery on Pad 39A at the Kennedy Space Center in Cape Canaveral, Fla. Discovery's final launch was delayed until Thursday. (Associated Press)

NASA workers walk along a platform on the service structure next to space Shuttle Discovery on Pad 39A at the Kennedy Space Center in Cape Canaveral, Fla. Discovery's final launch was delayed until Thursday. (Associated Press)