The Space Shuttle was a partly reusable space transportation system operated by NASA on 135 missions, between 1981 and 2011, to deliver payloads into low Earth orbit.
NASA’s space shuttle fleet comprised a total of six orbital vehicle (OV) spacecraft:
- Enterprise (OV-101), in use 1976 to 2012
- Columbia (OV-102), in use 1981 to 2003
- Challenger (OV-099), in use 1983 to 1986
- Discovery (OV-103), in use 1984 to 2011
- Atlantis (OV‑104), in use 1985 to 2011
- Endeavour (OV-105), in use 1992 to 2011
Of these six vehicles, both Challenger and Columbia were tragically lost in mission accidents (on 28 January 1986 and 1 February 2003, respectively), along with their crews, totaling 14 people.
Enterprise was a test vehicle with no orbital capability, constructed in 1976, and Endeavour was built from spare components to replace Challenger, in 1991.
Launch, Landing and Recovery
The Space Shuttle was launched vertically, on the the back of an expendable external fuel tank, (containing liquid hydrogen and liquid oxygen), which powered the shuttle’s three main integrated engines and was attached to a pair of recoverable solid rocket boosters (SRBs).
The shuttle’s orbital vehicle separated from the SRBs two minutes after launch, at around 46 km, before reaching orbital altitude. The external fuel tank was then jettisoned just prior to orbital insertion.
Following re-entry into the Earth’s atmosphere, the Shuttle would glide in to land on a conventional runway, usually at the Kennedy Space Center, Florida, or Rogers Dry Lake in Edwards Air Force Base, California. In order to return the Shuttle OVs to the Kennedy Space Centre, after landing elsewhere, two Boeing 747s were converted to allow an orbiter to ride on the aircrafts’ backs.
The SRBs, which were parachuted back to Earth, were recovered from the ocean and reused – with only four ever lost, in total (two from parachute failure, and two in the Challenger disaster). The external fuel tank (which broke up before impact in the ocean, away from shipping lanes), was the only part of the Space Shuttle system that was not reused.
