The Space Shuttle was a partially reusable low Earth orbital spacecraft system operated by NASA (the National Aeronautics and Space Administration). Its official program name was Space Transportation System (STS), taken from a 1969 plan for a system of reusable spacecraft of which it was the only item funded for development. Operational missions launched numerous satellites, conducted science experiments in orbit, and participated in construction and servicing of the International Space Station (ISS). 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, all launched from Kennedy Space Center in Florida. During that time period the fleet logged 1,322 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 one minute 13 seconds when the Space Shuttle Challenger broke apart during launch. The cold morning shrank an O-Ring on the right Solid Rocket Booster causing the external fuel tank to explode. The shuttles docked with Russian space station Mir nine times and visited the ISS thirty-seven times. The highest altitude (apogee) achieved by the shuttle was 386 mi (621 km) when deploying the Hubble Space Telescope. The program flew a total of 355 people representing 16 countries, and with 852 total shuttle fliers. The Kennedy Space Center served as the landing site for 78 missions, while 54 missions landed at Edwards Air Force Base in California and one mission landed at White Sands, New Mexico.
