English: The STS-117 crew members head for the astrovan that will take them to Launch Pad 39A. From left are Mission Specialists John "Danny" Olivas, James Reilly and Patrick Forrester; astronaut Clayton Anderson; Pilot Lee Archambault; Mission Specialist Steven Swanson; and Commander Frederick Sturckow. Anderson is joining the Expedition 15 crew on the International Space Station; Flight Engineer Suni Williams will return to Earth in his place. Liftoff is scheduled for 7:38 p.m. today aboard Space Shuttle Atlantis. 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.