STS-1 was the first orbital spaceflight of NASA's Space Shuttle program. The first orbiter, Columbia, launched on April 12, 1981, and returned on April 14, 1981, 54.5 hours later, having orbited the Earth 37 times. Columbia carried a crew of two—mission commander John W. Young and pilot Robert L. Crippen. It was the first American crewed space flight since the Apollo–Soyuz Test Project (ASTP) in 1975. STS-1 was also the maiden test flight of a new American spacecraft to carry a crew, though it was preceded by atmospheric testing (ALT) of the orbiter and ground testing of the Space Shuttle system.

The Space Shuttle program was the fourth human spaceflight program carried out by the U.S. National Aeronautics and Space Administration (NASA), which accomplished routine transportation for Earth-to-orbit crew and cargo from 1981 to 2011. Its official name, Space Transportation System (STS), was taken from a 1969 plan for a system of reusable spacecraft of which it was the only item funded for development. It flew 135 missions and carried 355 astronauts from 16 countries, many on multiple trips.