Space Shuttle Atlantis leaps off Launch Pad 39A alongside the fixed service structure with the lightning mast.

Space Shuttle Atlantis leaps off Launch Pad 39A alongside the fixed service structure (at left) with the 80-foot-tall lightning mast on top. Water flooding the mobile launcher platform for sound suppression create billows of steam that flow across the pad. The water originates from the 290-foot-high tank at right. Liftoff of Atlantis on mission STS-117 to the International Space Station from Launch Pad 39A was on-time at 7:38:04 p.m. EDT. The shuttle is delivering a new segment to the starboard side of the International Space Station's backbone, known as the truss. Three spacewalks are planned to install the S3/S4 truss segment, deploy a set of solar arrays and prepare them for operation. STS-117 is the 118th space shuttle flight, the 21st flight to the station, the 28th flight for Atlantis and the first of four flights planned for 2007. Photo credit: NASA/Tony Gray and Don Kight