Space shuttle Atlantis is revealed on Launch Pad 39A at NASA's Kennedy Space Center was rolled back.

Space shuttle Atlantis is revealed on Launch Pad 39A at NASA's Kennedy Space Center after the rotating service structure, or RSS, at left of the pad was rolled back. Rollback was complete at 9:49 p.m. EST. The RSS provides protected access to the orbiter for crew entry and servicing of payloads at the pad. Beneath the shuttle is the mobile launcher platform which supports the shuttle until liftoff. Rollback of the pad's RSS is one of the milestones in preparation for the launch of mission STS-122. Launch was originally set for Dec. 6 but was rescheduled to 3:21 p.m. Dec. 9. The delay was caused by problems with the external tank's engine cutoff sensor system that arose during tanking on Dec. 6. Atlantis will carry the Columbus Laboratory, the European Space Agency's largest contribution to the construction of the International Space Station. It will support scientific and technological research in a microgravity environment. Permanently attached to the Harmony node of the space station, the laboratory will carry out experiments in materials science, fluid physics and biosciences, as well as perform a number of technological applications. Photo credit: NASA/Amanda Diller