Criticism of the Space Shuttle program (approximately $ per pound adjusting for inflation to 2011). It failed in the goal of achieving reliable access to space, partly due to multi-year interruptions in launches following Shuttle failures. NASA budget pressures caused by the chronically high NASA Space Shuttle program costs have eliminated NASA manned space flight beyond low earth orbit since Apollo, and severely curtailed use of unmanned probes. NASA's promotion of and reliance on the Shuttle slowed domestic commercial expendable launch vehicle (ELV) programs until after the 1986 "Challenger" disaster. "Space Transportation System" (NASA's formal name for the overall Shuttle program) was created to transport crewmembers
Space Shuttle changes before it could be completed, the retirement of the Space Shuttle was delayed several times until 2011, serving at least 15 years longer than originally planned. "Discovery" was the first of NASA's three remaining operational Space Shuttles to be retired. The final Space Shuttle mission was originally scheduled for late 2010, but the program was later extended to July 2011 when Michael Suffredini of the ISS program said that one additional trip was needed in 2011 to deliver parts to the International Space Station. The Shuttle's final mission consisted of just four astronauts—Christopher Ferguson (Commander), Douglas Hurley (Pilot), Sandra