Trailing smoke and fire, Space Shuttle Atlantis roars into the sky past the U.S. flag on its journey to the International Space Station on mission STS-117. Liftoff 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/Ken Thornsley