STS-114 was the first Return to Flight mission since the tragic loss of Columbia February 1, 2003. Two and a half years were spent researching and implementing safety improvements for orbiters and external tanks. They included greater in-depth examination of Reinforced Carbon-Carbon panels that are used on the wing leading edges, plus replacing bolts and new foam applications on the tanks.
The STS-114 crewmembers delivered supplies to the International Space Station (ISS), but the crewmembers's primary objectives were to test and evaluate new safety procedures and conduct assembly and maintenance tasks on the Station. Two crewmembers, Steve Robinson and Soichi Noguchi, ventured outside the Shuttle three times on spacewalks. They first demonstrated repair techniques on the Shuttle'ss protective tiles, known as the Thermal Protection System. During the second spacewalk, they replaced a failed Control Moment Gyroscope, which helps keep the Station oriented properly. Finally, they installed the External Stowage Platform, a sort of space shelf for holding spare parts during Station construction. They also repaired the heat shield on the final spacewalk.
Several Detailed Supplementary Objectives (DSOs) were also flown during the STS-114 mission. DSOs 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. DSOs performed during this mission were:
Space Shuttle Discovery returned to Kennedy Space Center in Florida on August 9th bringing STS-114 to an end. This flight was the orbiter's 32nd mission and the 113th in the Shuttle program's history.