Space Shuttle Atlantis sits on the hardstand of Launch Pad 39B after its nearly 8 hour rollout from the Vehicle Assembly Building.

Space Shuttle Atlantis sits on the hardstand of Launch Pad 39B after its nearly 8-hour rollout from the Vehicle Assembly Building. Extending from the fixed service structure on the left is the orbiter access arm, with the White Room on the outer end, adjacent to Atlantis. Below the orbiter, on each side of the main engine nozzles, are the tail service masts that provide several umbilical connections to the orbiter, including a liquid-oxygen line through one and a liquid-hydrogen line through another. Atlantis' launch window begins Aug. 27 for an 11-day mission to the International Space Station. The STS-115 crew of six astronauts will continue construction of the station and install their cargo, the Port 3/4 truss segment with its two large solar arrays. Photo credit: NASA/Troy Cryder & George Shelton