Under a sky brushed with gray clouds sits Space Shuttle Endeavour on Launch Pad 39A.

Under a sky brushed with gray clouds sits Space Shuttle Endeavour on Launch Pad 39A. Behind the shuttle are the rotating service structure, which can be rolled around to enclose the shuttle for access during processing, and the fixed service structure, topped by an 80-foot-tall lightning mast. At right is the 290-foot-tall water tank, which provides the deluge over the mobile launcher platform for sound suppression during liftoff. Endeavour is scheduled to launch on mission STS-118 on Aug. 7. During the mission, Endeavour will carry into orbit the S5 truss, SPACEHAB module and external stowage platform 3. The mission is the 22nd flight to the International Space Station and will mark the first flight of Mission Specialist Barbara Morgan, the teacher-turned-astronaut whose association with NASA began more than 20 years ago. STS-118 will be the first flight since 2002 for Endeavour, which has undergone extensive modifications, including the addition of safety upgrades already added to orbiters Discovery and Atlantis. Photo credit: NASA/Ken Thornsley