The space shuttle Discovery is slowly heading out to the launch pad at Kennedy Space Center.
The move had been delayed because a crack was discovered in the foam insulation on the external fuel tank. Officials decided the crack was no reason for concern.
It's the first time a shuttle's been readied for launch since "Columbia" broke apart during its return two years ago. The disaster was blamed on a chunk of foam that fell off during takeoff and ripped a hole in a wing. All seven astronauts died in the disintegration over Texas.
The tank has been extensively redesigned for Discovery's flight.
NASA plans to launch Discovery next month for a mission to the international space station.