At NASA's Kennedy Space Center in Florida, space shuttle Discovery is visible on Launch Pad 39A and a sign supporting the vehicle hangs on the pad perimeter gate. Later, the rotating service structure that protects the shuttle from the elements will be moved into place. It took the spacecraft about six hours to make the journey, known as ''rollout,'' from the Vehicle Assembly Building to the pad. On its final mission, Discovery will take the Permanent Multipurpose Module (PMM) packed with supplies and critical spare parts, as well as Robonaut 2 (R2) to the International Space Station. Image credit: NASA/Jim Grossmann Sept. 21, 2010
