Space Shuttle Endeavour is revealed after rollback of the rotating service structure or RSS at left of the pad.

Space Shuttle Endeavour is revealed on Launch Pad 39A after rollback of the rotating service structure, or RSS, at left of the pad. Rollback started at 9 p.m. EDT Aug. 7 and was complete at 10:40 p.m. Beneath the shuttle is the mobile launcher platform which supports the shuttle until liftoff. The RSS provides protected access to the orbiter for changeout and servicing of payloads at the pad. Rollback of the pad's RSS is one of the milestones in preparation for the launch of mission STS-118 at 6:36 p.m. EDT on Aug. 8. Space Shuttle Endeavour's STS-118 mission is the 22nd shuttle flight to the International Space Station. It will continue space station construction by delivering a third starboard truss segment, S5, and other payloads such as the SPACEHAB module and the external stowage platform 3. Photo credit: NASA/Kim Shiflett