The U.S. Space Shuttle program started with the awarding of the contract to Rockwell International's Space Transportation Systems Division. There were 6 shuttles built, Enterprise OV- 101 (Orbital Vehicle) for testing, Columbia OV-102, Challenger OV-099, Discovery OV-103, Atlantis OV-104 and Endeavour OV-105. The first of 135 Space Shuttle missions took place April 12, 1981 and lasted 2 days 6 hours when STS-1 (Space Transportation System) was launched using Space Shuttle Columbia. Of the 135 mission launches there were 2 tragedies when Columbia and Challenger plus their crews were lost.
The first Space Shuttle was designated OV-101 and named Constitution making its public appearance on Constitution Day, September 17, 1976. After hundreds of thousands of letters from Star Trek fans the name was changed to Enterprise. On February 18, 1977 the craft completed its first captive flight followed on June 18, 1977 by the first crewed captive flight. On August 12, 1977 the Enterprise completed its first free flight and on October 26, 1977 astronauts Fred Haise and Gordon Fullerton completed approach and landing test flight at NASA’s Dryden Flight Research Center at Edwards AFB.