10/01/1946 US Army establishes 1st radar contact with Moon
Radar Makes Round Trip To Moon 1946-01-31 Universal Newsreel Project Diana Earth-Moon-Earth
#225: Introduction to the Project Diana 70th Anniversary Special Event
Project Diana was an experimental project of the US Army Signal Corps to bounce radar signals off the Moon and receive the reflected signals. This was the first experiment in radar astronomy and the first active attempt to probe another celestial body. It was the inspiration for later Earth-Moon-Earth communication techniques.