Imagination is more important than knowledge. Knowledge is limited. Imagination embraces the galaxy.
The Space Shuttle was a partially reusable low Earth orbital spacecraft system operated by the U.S. National Aeronautics and Space Administration (NASA). Its official program name was Space Transportation System, taken from a 1969 plan for a system of reusable spacecraft of which it was the only item funded for development. The first of four orbital test flights occurred in 1981, leading to operational flights beginning in 1982.
From 1981 to 2011 a total of 135 missions were flown, launched from Kennedy Space Center (KSC) in Florida. During that time the fleet totaled 1322 days, 19 hours, 21 minutes and 23 seconds of flight time. The longest orbital flight of the shuttle was STS-80 at 17 days 15 hours, while the shortest flight was STS-51-L at 1 minute 13 seconds, cut short when the space shuttle Challenger broke apart during launch. The shuttles docked with Russian space station Mir nine times and visited the ISS 37 times. The highest altitude achieved by the shuttle was 350 miles when servicing the Hubble Space Telescope. The program flew a total of 355 people representing 16 countries. The Kennedy Space Center served as the landing site for 78 missions while 54 missions landed at Edwards Air Force Base,California and one at White Sands, New Mexico.
The first orbiter, Enterprise, was built purely for atmospheric flight tests and had no orbital capability. Four full operational orbiters were initially built: Columbia, Challenger,Discovery, and Atlantis. Challenger and Columbia were destroyed in mission accidents in 1986 and 2003 respectively, killing a total of fourteen astronauts. A fifth operational orbiter, Endeavour, was built in 1991 to replace Challenger. The Space Shuttle was retired from service upon the conclusion of STS-135 by Atlantis on 21 July 2011.