SPACE SHUTTLE ENDEVOUR

Space Shuttle Endeavour (Orbiter Vehicle Designation: OV-105) is one of three currently operational orbiters in the Space Shuttle fleet of NASA, the space agency of the United States.^[1] (The other two are Discovery and Atlantis.) Endeavour is the fifth and final spaceworthy NASA space shuttle to be built, constructed as a replacement for Challenger. Endeavour first flew in May 1992 on mission STS-49 and was scheduled for decommissioning in 2010.^[2] Before its decommissioning, NASA expects to use Endeavour for the STS-134 mission, which will make it the last shuttle to fly a mission for the Space Shuttle Program.^[3] However, should the proposed STS-135 mission be approved, Atlantis will be the final shuttle to fly.

Contents [show] 1 History 2 Upgrades and features 3 Planned decommissioning 4 Flights 4.1 Tribute and mission insignias 5 See also 6 References 7 External links

[edit] History

Endeavour straddling the stratosphere and mesosphere.

The United States Congress authorized the construction of Endeavour in 1987 to replace Challenger, which was lost in an accident in 1986. Structural spares from the construction of Discovery and Atlantis, two of the three remaining operating shuttles at the time, were used in its assembly. The decision to build Endeavour was favored over refitting Enterprise on cost grounds.
The orbiter is named after the British HMS Endeavour, the ship which took Captain James Cook on his first voyage of discovery (1768–1771).^[4] This is why the name is spelled in the British English manner, rather than the American English ("Endeavor"). This has caused confusion, most notably when NASA themselves misspelled a sign on the launch pad in 2007.^[5] The name also honored Endeavour, the Command Module of Apollo 15.
Endeavour was named through a national competition involving students in elementary and secondary schools. Entries included an essay about the name, the story behind it and why it was appropriate for a NASA shuttle, and the project that supported the name. Endeavour was the most popular entry, accounting for almost one-third of the state-level winners. The national winners were Senatobia Middle School in Senatobia, Mississippi, in the elementary division and Tallulah Falls School in Tallulah Falls, Georgia, in the upper school division. They were honored at several ceremonies in Washington, D.C., including a White House ceremony where then-President George H.W. Bush presented awards to each school.^[6]
Endeavour was delivered by Rockwell International in May 1991 and first launched a year later, in May 1992, on STS-49. Rockwell International claimed that it had made no profit on Space Shuttle Endeavour, despite construction costing US$2.2 billion. On its first mission, it captured and redeployed the stranded INTELSAT VI communications satellite. The first woman of color, Mae Jemison, was brought into space on the mission STS-47 on September 12th, 1992.
In 1993, it 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, it delivered the Unity Module to the International Space Station.
Endeavour completed its latest Orbiter Major Modification period, which began in December 2003, and ended on October 6, 2005. During this time, the Orbiter received major hardware upgrades, including a new, multi-functional, electronic display system, often referred to as glass cockpit, and an advanced GPS receiver, along with safety upgrades recommended by the Columbia Accident Investigation Board (CAIB) for shuttle return to flight after the disintegration of sister-ship Columbia during re-entry on February 1, 2003.
The STS-118 mission, the first for Endeavour following a lengthy refit, included astronaut Barbara Morgan, formerly assigned to the Educator Astronaut program, but now a full member of the Astronaut Corps, as part of the crew. Morgan was the backup for Christa McAuliffe on the ill-fated STS-51-L mission.

[edit] Upgrades and features

Endeavour mounted on a Shuttle Carrier Aircraft.

As it was constructed later, 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 is expected to reduce the orbiter's rollout distance by 1,000 to 2,000 feet (300 to 610 m).
• 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 by Columbia).
• 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.

Modifications resulting from a 2005-2006 refit of Endeavour include:

• The Station-to-Shuttle Power Transfer System (SSPTS), which converts 8 kilowatts of DC power from the ISS main voltage of 120VDC to the orbiter bus voltage of 28VDC. This upgrade will allow 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.^[7][8][9]

[edit] Planned decommissioning

This section's factual accuracy may be compromised because of out-of-date information. Please help improve the article by updating it. There may be additional information on the talk page. (November 2010)

Platforms around Endeavour in Orbiter Processing Facility-2.

Endeavour was originally scheduled to be decommissioned in 2010 after 18 years of service, but on July 1, 2010, NASA released a statement saying the shuttle Endeavour mission was rescheduled for February 27, 2011, instead of late November, 2010.^[10]
"The target dates were adjusted because critical payload hardware for STS-133 will not be ready in time to support the previously planned September 16 launch," NASA said in a statement. With the Discovery launch moving to November, the Endeavour mission "cannot fly as planned, so the next available launch window is in February 2011," NASA said, adding that the launch dates are subject to change.
Endeavour's final flight was originally scheduled for July 29, 2010, but was postponed. Discovery was going to be the last of the Space Shuttle program, on the STS-133 mission to the International Space Station, which will carry the next to final components in the ISS assembly sequence, the EXPRESS Logistics Carrier ELC5 and ELC1, to orbit. However, in 2008 one more mission (STS-134) was funded, and so Endeavour was then slated to be the final Orbiter to fly. However, one final mission, STS-135, has also been added to the schedule and has been allocated to Atlantis for June 2011.
NASA has offered the three remaining orbiters for museum donation once they are withdrawn from service. Discovery may go the Steven F. Udvar-Hazy Center of the National Air and Space Museum but this decision has not yet been finalized.^[11].
More than twenty organizations have submitted proposals to NASA for the display of an Orbiter.^[12] March Field Air Museum in Riverside, California has stated a preference to receive Endeavour, due to the local connection of astronaut Tracy Caldwell, who grew up in Beaumont and flew on Endeavour during mission STS-118.^[13] Another organization seeking an Orbiter, and with a direct connection to Endeavour, is the forthcoming Brazos Valley Museum of Science and History. The Museum is endorsed in its efforts by President George H. W. Bush during whose terms as Vice President, and then President Endeavour was commissioned and first flown.^[14][15]