Space Shuttle Endeavour launches on STS-126 to continue assembly of the International Space Station.

Space Shuttle Endeavour is a retired orbiter from NASA's Space Shuttle program and the fifth and final operational Shuttle built. It embarked on its first mission, STS-49, in May 1992 and its 25th and final mission, STS-134, in May 2011. STS-134 was expected to be the final mission of the Space Shuttle program, but with the authorization of STS-135 by the United States Congress, Atlantis became the last shuttle to fly.

STS-126 was the one hundred and twenty-fourth NASA Space Shuttle mission, and twenty-second orbital flight of the Space Shuttle Endeavour (OV-105) to the International Space Station (ISS). 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 15 November 2008 at 00:55:39 UTC from Launch Pad 39A (LC-39A) at NASA's Kennedy Space Center (KSC) with no delays or issues. Endeavour successfully docked with the station on 16 November 2008. After spending 15 days, 20 hours, 30 minutes, and 30 seconds docked to the station, during which the crew performed four spacewalks, and transferred cargo, the orbiter undocked on 28 November 2008. Due to poor weather at Kennedy Space Center, Endeavour landed at Edwards Air Force Base on 30 November 2008 at 21:25:09 UTC.

The process of assembling the International Space Station (ISS) has been under way since the 1990s. Zarya, the first ISS module, was launched by a Proton rocket on 20 November 1998. The STS-88 Space Shuttle mission followed two weeks after Zarya was launched, bringing Unity, the first of three node modules, and connecting it to Zarya. This bare 2-module core of the ISS remained uncrewed for the next one and a half years, until in July 2000 the Russian module Zvezda was launched by a Proton rocket, allowing a maximum crew of three astronauts or cosmonauts to be on the ISS permanently.