Columbia was the first of five Space Shuttle orbiters to fly in space, debuting the Space Shuttle launch vehicle on its maiden flight in April 1981. As only the second full-scale orbiter to be manufactured after the Approach and Landing Test vehicle Enterprise, Columbia retained unique features indicative of its experimental design compared to later orbiters, such as test instrumentation and distinctive black chines. In addition to a heavier fuselage and the retention of an internal airlock throughout its lifetime, these made Columbia the heaviest of the five spacefaring orbiters

Challenger was the second Space Shuttle orbiter to fly into space after Columbia, and launched on its maiden flight in April 1983. It was destroyed in January 1986 soon after launch in an accident that killed all seven crewmembers aboard. During its three years of operation, Challenger was flown on ten missions in the Space Shuttle program, spending over 62 days in space and completing almost 1,000 orbits around Earth. Following its maiden flight, Challenger supplanted Columbia as the leader of the Space Shuttle fleet, being the most-flown orbiter during all three years of its operation while Columbia itself was seldom used during the same time frame.

Its first mission, STS-41-D, flew from August 30 to September 5, 1984. Over 27 years of service it launched and landed 39 times, aggregating more spaceflights than any other spacecraft to date. Discovery became the third operational orbiter to enter service, preceded by Columbia and Challenger. It embarked on its final mission, STS-133, on February 24, 2011, and touched down for the last time at Kennedy Space Center on March 9,  having spent a cumulative total of nearly a full year in space. Discovery performed both research and International Space Station (ISS) assembly missions, and also carried the Hubble Space Telescope into orbit among other satellites.

Atlantis was manufactured by the Rockwell International company in Southern California and was delivered to the Kennedy Space Center in Eastern Florida in April 1985. Atlantis is also the fourth operational and the second-to-last Space Shuttle built. Its maiden flight was STS-51-J made from October 3 to 7, 1985.Atlantis embarked on its 33rd and final mission, also the final mission of a space shuttle, STS-135, on July 8, 2011.By the end of its final mission, Atlantis had orbited the Earth a total of 4,848 times, traveling nearly 126,000,000 mi (203,000,000 km), which is more than 525 times the distance from the Earth to the Moon. Atlantis is named after RV Atlantis, a two-masted sailing ship that operated as the primary research vessel for the Woods Hole Oceanographic Institution from 1930 to 1966.