Project Mogul - Wikipedia

submited by

Style Pass

2021-05-25 01:00:07

Project Mogul (sometimes referred to as Operation Mogul) was a top secret project by the US Army Air Forces involving microphones flown on high-altitude balloons, whose primary purpose was long-distance detection of sound waves generated by Soviet atomic bomb tests. The project was carried out from 1947 until early 1949. It was a classified portion of an unclassified project by New York University (NYU) atmospheric researchers.[1] The project was moderately successful, but was very expensive and was superseded by a network of seismic detectors and air sampling for fallout, which were cheaper, more reliable, and easier to deploy and operate.

Project Mogul was conceived by Maurice Ewing who had earlier researched the deep sound channel in the oceans and theorized that a similar sound channel existed in the upper atmosphere: a certain height where the air pressure and temperature result in minimal speed of sound, so that sound waves would propagate and stay in that channel due to refraction. The project involved arrays of balloons carrying disc microphones and radio transmitters to relay the signals to the ground. It was supervised by James Peoples, who was assisted by Albert P. Crary.

One of the requirements of the balloons was that they maintain a relatively constant altitude over a prolonged period of time. Thus instrumentation had to be developed to maintain such constant altitudes, such as pressure sensors controlling the release of ballast.