During the mission, the crew delivered a third starboard truss segment for the station's backbone, installed a spare parts platform, and swapped out a failed gyroscope used to orient the station. It's was also the first flight of an educator astronaut, Mission Specialist Barbara R. Morgan. She was involved in an interactive educational inflight event with students gathered in Boise, Idaho to discuss her mission and the educational aspects of human spaceflight.
Several Detailed Supplementary Objectives (DSOs) and Supplemental Medical Objectives (SMOs) will also be flown during the STS-117 mission. DSOs and SMOs are space and life sciences investigations. Their purpose is to determine the extent of physiological deconditioning resulting from space flight, test countermeasures to those changes, and characterize the environment of the Space Shuttle and/or space station relative to crew health. Experiments being performed during this mission are:
Space Shuttle Endeavour returned to Kennedy Space Center in Florida on August 21st bringing STS-118 to an end. This flight was the orbiter's 20th mission and the 119th in the Shuttle program's history.