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 Enterprise Space Shuttle Enterprise Space Shuttle "Enterprise" (Orbiter Vehicle Designation: OV-101) was the first orbiter of the Space Shuttle system. Rolled out on September 17, 1976, it was built for NASA as part of the Space Shuttle program to perform atmospheric test flights after being launched from a modified Boeing 747. It was constructed without engines or a functional heat shield, and was therefore not capable of spaceflight. Originally, "Enterprise" had been intended to be refitted for orbital flight to become the second space-rated orbiter in service. However, during the construction of , details of the final design changed, making it