STS-126 was a Space Shuttle mission to the International Space Station (ISS), which was flown by the Space Shuttle Endeavour. The purpose of the mission, referred to as ULF2 by the ISS program, was to deliver equipment and supplies to the station, to service the Solar Alpha Rotary Joints (SARJ), and repair the problem in the starboard SARJ that had limited its use since STS-120. STS-126 launched on November 14, 2008 at 7:55:39 p.m. EST from Launch Pad 39A at NASA's Kennedy Space Center with no delays or issues. Endeavour successfully docked with the station on November 16. After spending 11 days, 16 hours, and 46 minutes docked to the station, during which the crew performed four spacewalks, and transferred cargo, the orbiter undocked on November 28. Due to poor weather at Kennedy Space Center, Endeavour landed at Edwards Air Force Base on November 30, at 21:25 UTC (1:25 p.m. PST).

Number in parentheses indicates number of spaceflights by each individual prior to this mission.

Originally scheduled to fly on STS-126 was Joan E. Higginbotham, who was a mission specialist on STS-116. On November 21, 2007, NASA announced a change in the crew manifest due to Higginbotham's decision to leave NASA to take a job in the private sector. Stephen Bowen was originally assigned to STS-124 but was moved to STS-126 to allow Discovery to rotate Greg Chamitoff with Garrett Reisman.