20 Years 1981-2001 Commemorative
STS-1, STS (Space Transportation System)-1, was the first flight of the Space Shuttle program, launched on April 12, 1981, and returning to Earth April 14. Space Shuttle Columbia orbited the earth 37 times in this 54.5-hour mission. It was the first US manned space flight since the Apollo-Soyuz Test Project on July 15, 1975, and the first (and so far only) manned maiden test flight of a new spacecraft system.
All Space Shuttle flights are referenced by their sequential chronological number, prefaced by the acronym "STS", which stands for "Space Transportation System", which is the proper way to refer to the collective parts of the Space Shuttle technologies used together.