Space Shuttle retirement

The retirement of NASA's Space Shuttle fleet took place from March to July 2011. Discovery was the first of the three active Space Shuttles to be retired, completing its final mission on March 9, 2011; Endeavour did so on June 1. The final shuttle mission was completed with the landing of Atlantis on July 21, 2011, closing the 30-year Space Shuttle program. The Space Shuttle was originally presented to the public in 1972 as a "space truck" which would, among other things, be used to build a United States space station in low Earth orbit in the early 1990s and then be replaced by a new vehicle. When the concept of the U.S. space station evolved into that of the International Space Station (ISS), which suffered from long delays and design changes before it could be completed, the service life of the Space Shuttle fleet was extended several times until 2011 when it was finally retired. After the Columbia loss in 2003, the Columbia Accident Investigation Board report showed that the Space Transportation System (STS) was risky and unsafe. In 2004, President George W. Bush announced (along with the VSE policy) that the Shuttles would be retired in 2010 (after completing ISS assembly). In 2010, Shuttle retirements began, with Atlantis being taken out of service first after STS-132 in May of that year. The program was once again extended when the two final planned missions were delayed until 2011. Later, one additional mission was added for Atlantis for July 2011, extending the program further. Counter-proposals to the shuttle's retirement were considered by Congress and the prime contractor United Space Alliance as late as Spring 2010.