The Mate-Demate Device was a specialized gantry crane designed to lift a Space Shuttle orbiter onto and off the back of a Shuttle Carrier Aircraft (SCA). Two Mate-Demate Devices were built, one at the Armstrong Flight Research Center in California, the other at the Kennedy Space Center in Florida. A third Orbiter Lifting Fixture was to serve a similar function at the Vandenberg Air Force Base, the proposed West Coast launch location for the Shuttle. It was later moved to Palmdale to support the plant where the Shuttle was built and refurbished. A portable sling was also built to support mate-demate operations away from the primary locations.