Shuttle Endeavour Overview

by Chris Bergin

Shuttle Endeavour (OV-105) was authorized by Congress in August 1987 as a replacement vehicle for the Space Shuttle Orbiter – Challenger (OV-099) which was destroyed on January 28th 1986.

Endeavour was named after a ship chartered to traverse the South Pacific in 1768 and captained by 18th century British explorer James Cook, an experienced seaman, navigator and amateur astronomer.

Endeavour (OV-105) was transported to Kennedy Space Center’s Shuttle Landing Facility on May 7th 1991, after having been carried on the back of NASA’s new Space Shuttle Carrier Aircraft.  Her first launch – flight STS-49 – was exactly one year later on May 7th 1992.
The Shuttle’s milestones include her primary assignment of capturing INTELSAT VI, an orbiting, but non functioning, communications satellite, and replace its rocket motor. Unfortunately, the Space Shuttle Endeavour was not designed to retrieve the satellite and this created many repair challenges.
The project sparked public interest in the mission as it took three attempts to capture the satellite for repairs to be made. An unprecedented three-person spacewalk took place after the procedure was evaluated by the astronauts and ground team.

Between rescue attempts, the STS-49 crew was busy with a variety of activities. They conducted medical tests assessing the human body’s performance in microgravity, and recorded footage for an educational video comparing Cook’s first voyage on Endeavour with the Space Shuttle orbiter’s maiden voyage.

Once the new motor was attached, it propelled the satellite into the correct orbit, providing a relay link for the equivalent of 120,000 two-way simultaneous telephone calls and three television channels.

This was the first time four spacewalks were conducted on a Space Shuttle mission and one of them was the longest in space history, lasting more than eight hours.
Endeavour (OV-105) then went on to become the first Space Shuttle Orbiter to use a drag chute during a landing — only one of many technical improvements made to Endeavour.

Just as James Cook set the standard with his seafaring Endeavour voyage, the Space Shuttle Endeavour missions have continued to uphold and surpass the standards set by its namesake, more than 200 years later.
Construction Milestones:
February 15, 1982 Start structural assembly of Crew Module
July 31, 1987 Contract Award
September 28, 1987 Start structural assembly of aft-fuselage
December 22, 1987 Wings arrive at Palmdale, Calif. from Grumman
August 1, 1987 Start of Final Assembly
July 6, 1990 Completed final assembly
April 25, 1991 Rollout from Palmdale
May 7, 1991 Delivery to Kennedy Space Center
April 6, 1992 Flight Readiness Firing
May 7, 1992 First Flight (STS-49)

Upgrades and Features:

Spare parts from the construction of Discovery (OV-103) and Atlantis (OV-104), manufactured to facilitate the repair of an orbiter if needed, were eventually used to build OV-105.

Endeavour also featured 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 reduces the orbiter’s rollout distance by 1,000 to 2,000 feet.
  • An updated avionics system 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.
  • Improved nose wheel steering mechanisms.
  • An improved version of the Auxiliary Power Units that provide power to operate the Space Shuttle’s hydraulic systems.
  • Installation of an external airlock, making Endeavour capable of docking with the International Space Station.
  • Originally equipped as the first extended duration orbiter, later removed during OMDP to save weight for ISS missions.
  • Installation of a ground cooling hookup to allow payload bay to cool the mini-pressurized logistics module (MPLM).
  • General weight-reduction program to maximize the payload capability to the ISS.
  • Doublers added to several wing spars to allow heavier payloads and two wing glove truss tubes were replaced with units having increased wall thickness.
  • Approximately 100 modifications made to Endeavour during its first Orbiter Major Modification period (OMDP).
Space Shuttle Endeavour is presently in its OMDP, which began in December 2003, preparing for a safe Return to Flight.

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