The Space Shuttle program was a series of missions conducted by NASA from 1981 to 2011. It involved reusable spacecraft designed to transport astronauts and cargo to and from low Earth orbit. The program included 135 missions, with notable achievements such as deploying satellites, servicing the Hubble Space Telescope, and constructing the International Space Station. Each mission typically lasted from a few days to two weeks, featuring a launch, orbit operations, and a landing. The Space Shuttle fleet consisted of five orbiters: Columbia, Challenger, Discovery, Atlantis, and Endeavour. The program significantly advanced human space exploration and scientific research.