Sitting on top of the platform Space Shuttle Atlantis rolls out to Launch Pad 39B via the crawlerway.

Sitting on top of the mobile launcher platform, Space Shuttle Atlantis rolls out to Launch Pad 39B via the crawlerway. First motion out of the Vehicle Assembly Building was 1:05 a.m. The slow speed of the crawler results in a 6-hour trek to the pad approximately 4 miles away. 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