This December 1971 photograph shows the internal configuration of Skylab's Multiple Docking Adapter (MDA) as it appeared during the Crew Compartment and Function Review at the Martin-Marietta Corporation's Space Center facility in Denver, Colorado. At left is the control and display console for the Apollo Telescope Mount. Designed and manufactured by the Marshall Space Flight Center, the MDA housed a number of experiment control and stowage units and provided a docking port for the Apollo Command Module.