Six reusable space shuttle orbiters were built for the United States space program by Rockwell International - these becoming Atlantis, Challenger, Colombia, Discovery, Enterprise and Endeavor. Two were lost during missions (Colombia and Challenger) while four served their terms and retired as museum showpieces. Discovery, given the Orbiter Vehicle Designation of "OV-103", was born through a contract awarded on January 29th, 1979 and recorded its first mission on August 30th, 1984. Its final mission occurred on February 24th, 2011.
A total of 39 missions were flown by Discovery and involved some 252 crewmen covering just over one year of time in space (365 days, 22 hours). Her retired frame is on exhibit at the Steven F. Udvar-Hazy Center in Chantilly, Virginia (2016).
Discovery was of a slightly modified, lighter design compared to Columbia by the time it entered formal service, benefitting from testing completed on the frames of Columbia, Challenger and Enterprise prior. In 1983 she was to receive the liquid-fueled "Centaur-G" booster system but the Challenger incident derailed this installation. In 1995, she underwent a major refit to keep her a viable spacecraft for the near future.
During her time aloft, Discovery managed several notable achievements for itself, her crews and the United States space program. STS-41-D marked the second American woman in space, Judith Resnick (she would tragically perish in the Challenger disaster later). STS-31 saw the launching of the Hubble Space Telescope and STS-63 marked the first time the shuttle would be piloted by a female. STS-95 marked the return of astronaut John Glenn into space, then aged 77, making him the oldest man to accomplish the feat. STS-96 saw Discovery become the first shuttle to dock with the International Space Station (thirteen total docking actions were eventually recorded) and STS-92 became the 100th mission completed by the space shuttle program. STS-133 went down in history as Discovery's final mission.
On several occasions, and during warmer ties with the Russians, Discovery also docked with the Soviet-Russian space station "Mir".
STS-26 and STS-114 became notable missions in their own right for it was Discovery that put the American space program back on track following the mission disasters of Challenger and Columbia.
The end of Discovery's career finally arrived on March 9th, 2011 when she was formally decommissioned from active service in the NASA orbiter fleet. The enter fleet has since been retired from active service.