Man in Space Communications System

Reliable communications are essential to success of the Lunar Excursion Module (LEM) mission in the Apollo program. This paper describes the communications system to provide the communications necessary for both in-flight and lunar-stay modes of operation. Features of the S-band transmission link between earth and the LEM vehicle, and the VHF transmission link between the Command Module and the LEM vehicle are discussed. The signal processor, S-band and VHF transceivers, S-band power amplifier, and steerable and erectable antenna assemblies comprising the communications system are described.