page_title: Space Shuttle Endeavour
section_title: Upgrades and features
hierarchical_section_title: Space Shuttle Endeavour / Service / Upgrades and features
caption_attribution_description: English: The Space Shuttle Endeavour atop its modified Boeing 747 carrier aircraft lifts off from Edwards Air Force Base on the first leg of its ferry flight back to the Kennedy Space Center just after sunrise on Dec. 10, 2008. Français&#160;: La navette spatiale américaine Endeavour sur un avion de transport Boeing 747 décolle de la base Edwards de l'US Air Force pour la première étape de son convoyage de retour pour le centre spacial Kennedy, juste après le lever du soleil le 10 décembre 2008.
context_page_description: 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, Atlantis became the last shuttle to fly.
  The United States Congress approved the construction of Endeavour in 1987 to replace Challenger, which was destroyed in 1986.
  Structural spares built during the construction of Discovery and Atlantis were used in its assembly. NASA chose, on cost grounds, to build Endeavour from spares rather than refitting Enterprise.
context_section_description: As it was constructed later than its elder sisters, Endeavour was built with new hardware designed to improve and expand orbiter capabilities. Most of this equipment was later incorporated into the other three orbiters during out-of-service major inspection and modification programs. ''Endeavour's upgrades include:
  A 40-foot (12 m) diameter drag chute that reduced the orbiter's landing roll-out distance (the runway length used for deceleration) from 3,000 feet (910 m) to 2,000 feet (610 m).
  The plumbing and electrical connections needed for Extended Duration Orbiter (EDO) modifications to allow up to a 28-day mission (although a 28-day mission was never attempted; the record is 17 days, which was set by Columbia).
  Updated avionics systems that included advanced general purpose computers, improved inertial measurement units and tactical air navigation systems, enhanced master events controllers and multiplexer-demultiplexers, a solid-state star tracker and improved nose wheel steering mechanisms.
  An improved version of the Auxiliary Power Units (APUs) that provided power to operate the Shuttle's hydraulic systems.
  Modifications resulting from a 2005–2006 refit of Endeavour included:
  The Station-to-Shuttle Power Transfer System (SSPTS), which converted 8 kilowatts of DC power from the ISS main voltage of 120VDC to the orbiter bus voltage of 28VDC. This upgrade allowed Endeavour to remain on-orbit while docked at ISS for an additional 3- to 4-day duration. The corresponding power equipment was added to the ISS during the STS-116 station assembly mission, and Endeavour flew with SSPTS capability during STS-118.
caption: Endeavour in flight en route back to the Kennedy Space Center atop a Shuttle Carrier Aircraft in 2008
exif: {}