STS115-318-026 (17 Sept. 2006) --- Backdropped by the blackness of space and Earth's horizon, the International Space Station moves away from Space Shuttle Atlantis. Earlier the STS-115 and Expedition 13 crews concluded six days of cooperative work onboard the shuttle and station. Undocking of the two spacecraft occurred at 7:50 a.m. (CDT) on Sept. 17, 2006. Atlantis left the station with a new, second pair of 240-foot solar wings, attached to a new 17.5-ton section of truss with batteries, electronics and a giant rotating joint. The new solar arrays eventually will double the station's onboard power when their electrical systems are brought online during the next shuttle flight, planned for launch in December.