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
Criticism of the Space Shuttle program Criticism of the Space Shuttle program Criticism of the Space Shuttle program stemmed from claims that NASA's Shuttle program failed to achieve its promised cost and utility goals, as well as design, cost, management, and safety issues. More specifically, it failed in the goal of reducing the cost of space access. Space Shuttle incremental per-pound launch costs ultimately turned out to be considerably higher than those of expendable launchers. By 2011, the incremental cost per flight of the Space Shuttle was estimated at $450 million, or $18,000 per kilogram (approximately $8,000 per pound) to low Earth orbit (LEO). By comparison,