STS-126, also called ULF-2, was a Utilization Logistics Flight that delivered logistics that are necessary to support the ISS crew. The space shuttle delivered Multi-Purpose Logistics Module Leonardo to ISS with 32,000 pounds of equipment. The MPLM was Endeavour’s major payload. It consisted of equipment for enlarging the space station’s capacity to accommodate a six-member crew. Some of the additions aboard were a crew galley, modular crew quarters, resistance exercise equipment, a Waste and Hygiene Compartment, and the Water Recovery System. The delivery of these elements made the space station capable of supporting a full complement of six crewmembers to live and work aboard ISS.
After docking with the station, the crew’s primary objectives were to unpack MPLM Leonardo and to inspect the station’s solar alpha rotary joint (SARJ). The SARJ is an essential part of the solar arrays which are the primary power supply for the station. Four choreographed space walks were performed to inspect the SARJ in a series of steps; which included removing the thermal covers, inspecting the SARJ joints, cleaning the surfaces, lubricating the joint, installing new bearing assemblies and reinstalling the thermal covers.
Detailed Supplementary Objectives (DSOs) and life science investigations were also flown on the STS-126 mission. A DSO is a NASA-sponsored investigation performed by Space Shuttle crewmembers, who serve as the test subjects. These studies required minimal crew time, power and stowage. Biomedical DSOs focus on operational concerns, including space motion sickness, cardiovascular deconditioning, muscle loss, changes in coordination and balance strategies, radiation exposure, pharmacokinetics and changes in the body's biochemistry.
The 15 day, 20 hour, 30 minute mission came to close on November 30, 2008, when the Space Shuttle landed at Edwards Air Force Base. This mission was a major milestone for ISS, by bringing the station to the capacity of housing a six-member crew. This was a tremendous way to acknowledge the 10-year anniversary of ISS. The orbital assembly of the space station began with the launch from Kazakhstan of its first bus-sized component, Zarya, on November 20, 1998.