STS-1 (Space Transportation System-1) was the first orbital spaceflight of NASA's Space Shuttle program.

The first orbiter, Columbia, launched on April 12, 1981,[1] and returned on April 14, 1981, 54.5 hours later, having orbited the Earth 37 times.

Columbia carried a crew of two—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.