 The facility was constructed by the United States Air Force in the late 1950s for the Titan I Missile Program, modified in 1964 for the Titan III Program, and further modified in the late 1980s for the Starbird launch vehicles associated with the shuttle Starlab mission.Several Titan I rockets and four or five Titan III rockets were launched from SLC-20.SLC-20 was deactivated in 1996.