Communication Moon Relay grew out of many ideas and concepts in radio espionage. Some impetus for the project was provided by post-World War II efforts to develop methods of tracking radio signals, particularly those originating in Eastern Europe and the Soviet Union. Other sources included earlier proposals to use the Moon as a radio wave reflector, which date back to 1928. The Project Diana program of the U.S. Army Signal Corps detected radar waves bounced off the Moon in 1946 and attracted the attention of Donald Menzel. Menzell was a staff member of the Harvard College Observatory and a former United States Navy Reserve commander, who proposed that the Navy undertake a program to use the Moon as a secure communications satellite.