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.
Space Shuttle Discovery Orbiter Vehicle Designation OV-103 was the third of five operational orbiters built. On August 30, 1984 Discovery departed on its first flight; STS-41D to deploy three communication satellites, SBS-D; SYNCOM IV-2 and Solar Wing TELSTAR with the mission lasting until September 5, 1984. The crew consisted of Hartsfield, Coats, Resnik, Mullane, Hawley and Walker. Discovery’s last mission was STS-133 that lasted from February 24, 2011 until March 9, 2011. With retirement of Discovery it had traveled 148,221,675 miles, spent 365 days in space made 39 flights.