The multiple docking adapter (MDA) was part of Skylab, America's first space station. Three-man astronaut crews traveling to and from Skylab in Apollo spacecraft docked to the main docking port at one end of the cylindrical MDA. A second docking port on the side of the MDA was reserved for emergency use. The MDA also served as the control center for solar observations, Earth resources observations, and materials processing experiments.
Two complete Skylab space stations were manufactured and equipped for flight. One was launched into Earth orbit in 1973; the backup Skylab resides in the National Air and Space Museum. The backup MDA was exhibited in the Museum's Space Hall from 1976-1996.
NASA transferred the MDA to the Museum in 1978.
This object is not on display at the National Air and Space Museum. It is either on loan or in storage.