Space Shuttle Discovery alone. "Discovery" flew all three "return to flight" missions after the "Challenger" and "Columbia" disasters: STS-26 in 1988, STS-114 in 2005, and STS-121 in 2006. "Discovery" flew the ante-penultimate mission of the Space Shuttle program, STS-133, having launched on February 24, 2011. "Endeavour" flew STS-134 and "Atlantis" performed STS-135, NASA's last Space Shuttle mission. On February 24, 2011, Space Shuttle "Discovery" launched from Kennedy Space Center's Launch Complex 39-A to begin its final orbital flight. The Flow Director was responsible for the overall preparation of the shuttle for launch and processing it after landing, and remained permanently assigned to head
Space Shuttle in a September 1969 report of a Space Task Group headed by Vice President Spiro Agnew to President Richard Nixon. Nixon's post-Apollo NASA budgeting withdrew support of all system components except the Shuttle, to which NASA applied the STS name. The vehicle consisted of a spaceplane for orbit and re-entry, fueled from an expendable External Tank containing liquid hydrogen and liquid oxygen, with two reusable strap-on solid rocket boosters. The first of four orbital test flights occurred in 1981, leading to operational flights beginning in 1982, all launched from the Kennedy Space Center, Florida. The system was retired from service