Ventilation fan and shroud assembly as used in the Multiple Docking Adapter (MDA) of the Skylab space station, measuring approximately 7.75″ x 12″ x 7″, with a blue George C. Marshall Space Flight Center identification plaque on the side: "Fan Assy (Muffled), Part No. 20M42270-3, Spec No. 20M42364, Unit Mfg. MSFC, Airesearch Fan Ser No. 91-154, Unit Wt. 9.94." The heavy-duty unit is also marked on both sides to indicate direction of airflow, and has black rubber gaskets on each end. Includes the original plastic packaging with affixed KSC parts tag stamped "Flight" (presumably denoting this as a flight-ready spare), bearing several inspection stamps dated 1982.
In a NASA technical report on the MSFC Skylab Multiple Docking Adapter, it was noted that 'the crews' evaluation on the performance of the ventilation system was that the air circulation was more than adequate…and that the operation of the fan-muffler assemblies produced a low level acoustic noise output. It was very quiet.'
