Five space shuttles were built for orbital flight: Columbia, Challenger, Discovery, Atlantis, and Endeavour. These five operational orbiters completed a combined 135 missions between 1981 and 2011.
The number can be confusing because NASA also built Enterprise, the first shuttle orbiter. Enterprise was used for atmospheric approach and landing tests beginning in 1977, but it was never equipped for orbital flight and never launched into space. It is therefore usually excluded from the count of orbit-capable shuttles.
Columbia became the first operational shuttle to reach orbit in 1981, followed by Challenger in 1983, Discovery in 1984, and Atlantis in 1985. Endeavour was completed in 1991 to replace Challenger after its loss in 1986 and began flying in 1992.
Two of the five orbital vehicles were later destroyed during missions: Challenger during launch in 1986 and Columbia during reentry in 2003. Discovery, Atlantis, and Endeavour completed the shuttle era, which ended with Atlantis's final flight in July 2011.