Project Mogul (sometimes referred to as Operation Mogul) was a top secret project by the US Army Air Forces involving high altitude balloons, whose primary purpose was long-distance detection of sound waves generated by Soviet atomic bomb tests and ballistic missiles. The project was carried out from 1947 until late 1948. A typical classified document. ... The United States Army Air Forces (USAAF) was a part of the U.S. Army during World War II. The direct precursor to the U.S. Air Force, the USAAF formally existed between 1941 and 1947. ... High altitude balloons are balloons, usually filled with helium, that are released into the upper atmosphere, generally reaching between 60,000 and 120,000 feet. ... This article is about compression waves. ... Motto: Пролетарии всех стран, соединяйтесь! (Transliterated: Proletarii vsekh stran, soedinyaytes!) Translation: Workers of the world, unite!) Anthem: The Internationale (1922-1944) Hymn of the Soviet Union (1944-1991) Capital Moscow Language(s) Russian Government Socialist republic Leaders  - 1922-1924 Vladimir Lenin  - 1924-1953 Joseph Stalin  - 1953-1964 Nikita Khrushchev  - 1964-1981 Leonid Brezhnev  - 1985... Preparation for an underground nuclear test at the Nevada Test Site in the 1980s. ... Diagram of V-2, the first ballistic missile. ... Year 1947 (MCMXLVII) was a common year starting on Wednesday (the link is to a full 1947 calendar). ... Year 1948 (MCMXLVIII) was a leap year starting on Thursday (the link is to a full 1948 calendar). ...

Project Mogul was conceived by Dr. 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 microphones and radio transmitters to relay the signals to the ground. It was supervised by Dr. James Peoples, who was assisted by Dr. Albert P. Crary. Dr. W. Maurice Ewing (May 12, 1906 – May 4, 1974) has been described as a pioneering geophysicist who worked on the research of seismic reflection and refraction in ocean basins, ocean bottom photography, submarine sound transmission, deep sea coring of the ocean bottom, theory and observation of earthquake surface waves... The SOFAR channel (SOund Fixing And Ranging channel), or deep sound channel, is a layer of water deep in the ocean where the speed of sound is at a minimum. ... Layers of Atmosphere (NOAA) Air redirects here. ... The straw seems to be broken, due to refraction of light as it emerges into the air. ... Albert Paddock Crary (1911 - 1987), was a pioneer polar geophysicist and glaciologist and the first person to set foot on both the North (1952 with Lieutenant Colonel Fletcher) and South Poles. ...

One of the requirements of the balloons was that they maintain a relatively constant altitude over a prolonged period of time. The early Mogul balloons consisted of large clusters of rubber meteorological balloons. However, these were quickly replaced by enormous balloons made of polyethylene plastic. These were more durable, leaked less helium, and also were better at maintaining a constant altitude than the early rubber balloons. Constant altitude control and polyethylene balloons were the two major innovations of Project Mogul. Rawinsonde weather balloon just after launch. ... This article or section does not cite its references or sources. ... General Name, Symbol, Number helium, He, 2 Chemical series noble gases Group, Period, Block 18, 1, s Appearance colorless Atomic mass 4. ...

Project Mogul was the forerunner of the Skyhook balloon program, which started in the late 1940s, as well as another espionage program involving overflights and photo-surveillance of the Soviet Union in the early 1950s, called Project Moby Dick^{[citation needed]}. The latter raised storms of protest from the Soviets. The balloons were also used for cosmic ray experiments. The skyhook balloon launched in 1957 to photograph the sun Skyhook ballons were balloons developed Otto C. Winzen and used by the United States Navy Office of Naval Research in the late 1940s and in the 1950s for atmospheric research, especially for constant-level meteorological observations at very high altitudes. ... Espionage (spying) is a practice of obtaining information about an organization or a society that is considered secret or confidential without the permission of the holder of the information. ... Cosmic rays can loosely be defined as energetic particles originating outside of the Earth. ...

Project Mogul and the Roswell UFO incident

Main article: Air Force Reports on Roswell UFO Incident

In 1994/5, the Air Force published a report claiming Mogul Flight #4, launched from Alamogordo, New Mexico on June 4, 1947, was what crashed near Roswell, New Mexico and sparked the Roswell UFO incident. The report claimed a combination of personnel unfamiliar with this sort of equipment who thought it might be one of numerous "flying saucers" being reported at the time and the desire on the part of the military to maintain secrecy on Mogul eventually led to the belief from many that the military was covering up a recovered alien spacecraft. The two Air Force reports on the Roswell UFO incident published in 1994/5 and 1997 form the basis for much of the skeptical explanation for the 1947 incident. ... Aircraft of the 379th Air Expeditionary Wing and coalition counterparts stationed together at Al Udeid Air Base, Qatar, in southwest Asia, fly over the desert. ... The two Air Force reports on the Roswell UFO incident published in 1994/5 and 1997 form the basis for much of the skeptical explanation for the 1947 incident. ... Alamogordo is a city located in Otero County, New Mexico, United States of America. ... Nickname: All America City Location in the state of New Mexico. ... Roswell Daily Record, July 8, 1947, announcing the capture of a flying saucer. ... UFO redirects here. ...

External links

• Report on Project Mogul - Synopsis of Balloon Research Findings, by James McAndrew, 1st Lt, USAFR
• Physics lecture video in which Prof. Richard A. Muller gives a detailed explanation of the science of Project Mogul (Google Video)