Space Shuttle Endeavour Space Shuttle Endeavour Space Shuttle "Endeavour" (Orbiter Vehicle Designation: OV-105) is a retired orbiter from NASA's Space Shuttle program and the fifth and final operational shuttle built. It embarked on its first mission, STS-49, in May 1992 and its 25th and final mission, STS-134, in May 2011. STS-134 was expected to be the final mission of the Space Shuttle program, but with the authorization of STS-135, "Atlantis" became the last shuttle to fly. The United States Congress approved the construction of "Endeavour" in 1987 to replace "Challenger", which was lost in 1986. Structural spares built during the construction of "Discovery"
Space Shuttle retirement 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, which suffered from long delays and design changes before it could be completed, the service life of the Space Shuttle was extended several times until 2011 when it was finally retired. In 2010 the Shuttle was formally scheduled for retirement with "Atlantis" being taken out of service first after STS-132 in May of that year, but the program was once again extended when the two final planned missions were delayed until 2011. Later, one additional mission