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 still has its 1983 markings and still has its name on the payload bay doors. The Space Shuttle was initially developed in the 1970s, but received many upgrades and modifications afterward to improve performance, reliability and safety. Internally, the Shuttle remained largely similar to the original design, with the exception of the improved avionics computers. In addition to the computer upgrades, the original analog primary flight instruments were replaced with modern full-color, flat-panel display screens, called a glass cockpit, which is similar to those of contemporary airliners. To facilitate construction of ISS, the internal airlocks of each orbiter except "Columbia"