Endeavour space shuttle
Space Shuttle Orbiter Endeavour (NASA Orbiter Vehicle Designation: OV-105), is the fifth and final operational NASA space shuttle to be built. Endeavour is often referred to as "the baby of the shuttle fleet," as she is the youngest shuttle, at only 14 years old.

The United States Congress authorized the construction of Endeavour in 1987 to replace Challenger, which was lost in an explosion in 1986. Structural spares from the construction of shuttles Discovery and Atlantis were used in its assembly. The decision to build Endeavour was favored over refitting Enterprise because it was cheaper.

Endeavour was delivered by Rockwell International in May 1991 and first launched a year later, in May 1992. Rockwell International claimed that they had made no profit on Space Shuttle Endeavour, in spite of it costing 2.2 billion dollars USD. On her first mission, she captured and redeployed the stranded INTELSAT VI communications satellite. In 1993, she made the first service mission to the Hubble Space Telescope. Endeavour was withdrawn from service for eight months in 1997 for a retrofit, including installation of a new airlock. In December 1998, she delivered the Unity Module to the International Space Station.

Endeavour was named through a national competition involving students in elementary and secondary schools. The orbiter is named after HM Bark Endeavour, the ship commanded by 18th century explorer James Cook; the name also honoured Endeavour, the Command Module of Apollo 15. This is why the name is spelled in the British English manner, rather than the American English spelling, "Endeavour".

As of August 2005, Endeavour is still in her Orbiter Major Modification period, which began in December 2003 and is expected to last through sometime in 2006. She is currently in the Orbiter Processing Facility Bay 2, along with her sister Atlantis, at NASA's Kennedy Space Centre in Florida.
Upgrades and features
Endeavour features 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 diameter drag chute that is expected to reduce the orbiter's rollout distance by 1,000 to 2,000 feet.
The plumbing and electrical connections needed for Extended Duration Orbiter (EDO) modifications to allow up to 28-day missions (although a 28-day mission has never yet been attempted; the current record is 17 days, which was set with the Columbia orbiter).

Updated avionics systems that include 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 provide power to operate the Shuttle's hydraulic systems.
Space Shuttle Endeavour has flown 19 flights, spent 206.60 days in space, completed 3,259 orbits, and flown 85,072,077 miles (136,910,237 km) in total, as of February 2003. She last flew in November 2002.
1992 May 7 STS-49 Capture and redeploy Intelsat VI. First three-man EVA and longest US EVA since Apollo 17
1992 Sep 12 STS-47 Spacelab mission J
1993 Jan 13 STS-54 Deploy TDRS-F
1993 Jun 21 STS-57 Spacelab experiments. Retrieve European Retrievable Carrier
1993 Dec  2 STS-61 First Hubble Space Telescope service mission
1994 Apr  9 STS-59 Space Radar Laboratory experiments
1994 Sep 30 STS-68 Space Radar Laboratory experiments
1995 Mar 30 STS-67 Spacelab Astro-2 experiments
1995 Sep  7 STS-69 Wake Shield Facility and other experiments
1996 Jan 11 STS-72 Retrieve Japanese Space Flyer Unit
1996 May 19 STS-77 Spacelab experiments
1998 Jan 22 STS-89 Rendezvous with Mir space station and astronaut exchange
1998 Dec 4 STS-88 International Space Station assembly mission
2000 Feb 11 STS-99 Shuttle Radar Topography Mission experiments
2000 Nov 30 STS-97 International Space Station assembly mission
2001 Apr 19 STS-100 International Space Station assembly mission
2001 Dec  5 STS-108 International Space Station rendezvous and astronaut exchange
2002 Jun  5 STS-111 International Space Station rendezvous and astronaut exchange
2002 Nov 23 STS-113 International Space Station assembly mission and astronaut exchange