Expedition Sixteen Flight Engineer Daniel Tani will serve as a mission specialist aboard Discovery before rotating positions with station resident NASA Astronaut Clayton Anderson after docking. Anderson arrived at the station aboard the Space Shuttle Atlantis during STS-117 in June 2007. Serving as the third Expedition Sixteen crewmember, Tani will join Expedition Sixteen Commander Peggy Whitson and Flight Engineer Yuri Malenchenko, who arrived at the station aboard a Russian Soyuz spacecraft in October 2007.
The Node 2 connecting module, Harmony, will travel to the station inside Space Shuttle Discovery's payload bay for installation on the station. This addition sets the stage for the arrival of new research laboratories from the European Space Agency and the Japan Aerospce Exploration Agency in upcoming shuttle missions. As part of assembling the giant laboratory, STS-120 astronauts will relocate the Port 6 (P6) truss element and solar arrays to a permanent position. P6 will be removed from its current location, reattached to the Port 5 (P5) truss and then the solar arrays will be redeployed and activated to gather sunlight for power generation.
Several Detailed Supplementary Objectives (DSOs) and Supplemental Medical Objectives (SMOs) will also be flown during the STS-120 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 Discovery returned to Kennedy Space Center in Florida on November 7th bringing STS-120 to an end. This flight was the orbiter's 34th mission and the 120th in the Shuttle program's history.