“This documentary is on the Mate/Demate Device (MDD) at Dryden Flight Research Center. The MDD was used to lower the Space Shuttle onto the host NASA 747 Shuttle Carrier Aircraft, which carried it across the U.S. to Kennedy Space Center, Fla. The structure has served NASA well, as Dryden was the primary landing site during the early days of the space shuttle program. About a year before it would hoist Space Shuttle prototype Enterprise onto the NASA 747 Shuttle Carrier Aircraft for the first time, the gargantuan steel frame had been erected and stood ready to do the heavy lifting.
The MDD consists of two 100-foot towers with stationary platforms every twenty feet from 20 to 80 feet on each tower, and a horizontal structure mounted at the 80-foot level between the two towers. The horizontal unit cantilevers 70 feet out from the main tower units, guiding and controlling a large lift beam that attaches to the orbiters to raise and lower them.
Three large hoists are used to raise and lower the lift beam. Two of the hoists are connected to the aft portion of the lift beam and one hoist is attached to the beam’s forward section. The three hoists operate simultaneously. As a unit the hoists can lift 120 tons, or 240,000 pounds, and the average space shuttle weighs in at about 231,000 pounds.”
Public domain film from NASA.
A Mate-Demate Device (MDD) is a specialized crane designed to lift a Space Shuttle orbiter onto and off of the back of a Shuttle Carrier Aircraft. Four Mate-Demate Devices were built…
Edwards Airforce Base MDD
The first MDD was located at Edwards Air Force Base in California 34.958559°N 117.883818°W. Many Space Shuttle missions were not able to land in Florida due to bad weather. All but one (STS-3) of these flights landed at Edwards instead. This MDD was used to hoist a Space Shuttle orbiter onto a Shuttle Carrier Aircraft for the flight back to Florida.
Kennedy Space Center MDD
The second MDD was located at the Kennedy Space Center in Florida 28.600666°N 80.679262°W. Its primary use was unloading the orbiter after its cross-country flight from Edwards.
Orbiter Lifting Fixture
The third MDD was built for the planned Space Shuttle operations at Vandenberg Air Force Base in California. Upon cancellation of Vandenberg’s shuttle program, the Orbiter Lifting Fixture (OLF) was disassembled and moved to USAF Plant 42 in Palmdale California where it was used during periodic orbiter refurbishments. This structure was demolished in 2008.
On the rare occasions when an orbiter needed to be loaded or unloaded at a location where no MDD was available, a pair of cranes was used instead. Prior to its use in 2012 to exchange Discovery and Enterprise, the mobile MDD had been stored for over twenty years.
MDDs in USSR
For the Energia-Buran programme there was built similar structures in USSR, named PKU-50, PU-100 and PUA-100.
For the time of the Buran first flight they were operated at LII, Baikonur Jubilee airfield and Bezymyanka airport.
They were capable of loading Buran (0GT cargo) or Energia components (1GT, 2GT and 3GT cargoes) on top of Myasishchev VM-T and Antonov An-225 aircraft.