The Communication Moon Relay project (also known as simply Moon Relay, or, alternatively, Operation Moon Bounce) was a telecommunication

Telecommunication

Telecommunication is the transmission of information over significant distances to communicate. In earlier times, telecommunications involved the use of visual signals, such as beacons, smoke signals, semaphore telegraphs, signal flags, and optical heliographs, or audio messages via coded...

 project carried out by the United States Navy

United States Navy

The United States Navy is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. The U.S. Navy is the largest in the world; its battle fleet tonnage is greater than that of the next 13 largest navies combined. The U.S...

. Its objective was to develop a secure and reliable method of wireless

Wireless

Wireless telecommunications is the transfer of information between two or more points that are not physically connected. Distances can be short, such as a few meters for television remote control, or as far as thousands or even millions of kilometers for deep-space radio communications...

 communication by using the Moon

Moon

The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...

 as a natural communications satellite

Communications satellite

A communications satellite is an artificial satellite stationed in space for the purpose of telecommunications...

 - a technique known as EME (Earth-Moon-Earth)

EME (communications)

Earth-Moon-Earth, also known as moon bounce, is a radio communications technique which relies on the propagation of radio waves from an Earth-based transmitter directed via reflection from the surface of the Moon back to an Earth-based receiver....

 communications. Most of the project's work took place during the 1950s at the U.S. Naval Research Laboratory. Operation Moon Relay was spun off from a classified military espionage program known as Passive Moon Relay (PAMOR).

Background

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

World War II

World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

 efforts to develop methods of tracking radio signals, particularly those originating in Eastern Europe

Eastern Europe

Eastern Europe is the eastern part of Europe. The term has widely disparate geopolitical, geographical, cultural and socioeconomic readings, which makes it highly context-dependent and even volatile, and there are "almost as many definitions of Eastern Europe as there are scholars of the region"...

 and the Soviet Union

Soviet Union

The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....

. Other sources included earlier proposals to use the Moon as a radio wave reflector, which date back to 1928. The Project Diana

Project Diana

Project Diana, named for the Roman moon goddess Diana — goddess of the hunt, wild animals and the moon — was a project of the US Army Signal Corps to bounce radio signals off the moon and receive the reflected signals...

 program of the U.S. Army Signal Corps  detected radar

Radar

Radar is an object-detection system which uses radio waves to determine the range, altitude, direction, or speed of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. The radar dish or antenna transmits pulses of radio...

 waves bounced off the Moon in 1946 and attracted the attention of Donald Menzel. Menzell was a staff member of the Harvard College Observatory

Harvard College Observatory

The Harvard College Observatory is an institution managing a complex of buildings and multiple instruments used for astronomical research by the Harvard University Department of Astronomy. It is located in Cambridge, Massachusetts, USA, and was founded in 1839...

 and a former United States Navy Reserve

United States Navy Reserve

The United States Navy Reserve, until 2005 known as the United States Naval Reserve, is the Reserve Component of the United States Navy...

 commander, who proposed that the Navy undertake a program to use the Moon as a secure communications satellite.

Prior to the Moon Relay project, long distance wireless transmission required that radio waves be refracted by the Earth's ionosphere

Ionosphere

The ionosphere is a part of the upper atmosphere, comprising portions of the mesosphere, thermosphere and exosphere, distinguished because it is ionized by solar radiation. It plays an important part in atmospheric electricity and forms the inner edge of the magnetosphere...

, which was sometimes disrupted by solar flare

Solar flare

A solar flare is a sudden brightening observed over the Sun surface or the solar limb, which is interpreted as a large energy release of up to 6 × 1025 joules of energy . The flare ejects clouds of electrons, ions, and atoms through the corona into space. These clouds typically reach Earth a day...

s and geomagnetic storm

Geomagnetic storm

A geomagnetic storm is a temporary disturbance of the Earth's magnetosphere caused by a disturbance in the interplanetary medium. A geomagnetic storm is a major component of space weather and provides the input for many other components of space weather...

s. The Moon, and, later, artificial satellites, provided a target from which to reflect radio waves, enabling them to be promulgated even when the ionosphere was disturbed.

The developments in Moon circuit communications eventually came to the attention of James Trexler, a radio engineer

Engineering

Engineering is the discipline, art, skill and profession of acquiring and applying scientific, mathematical, economic, social, and practical knowledge, in order to design and build structures, machines, devices, systems, materials and processes that safely realize improvements to the lives of...

 at the Naval Research Laboratory. His interest was piqued by a paper published by researchers at an ITT

ITT Corporation

ITT Corporation is a global diversified manufacturing company based in the United States. ITT participates in global markets including water and fluids management, defense and security, and motion and flow control...

 laboratory. Trexler developed plans for a system designed to intercept Soviet radar signals by detecting the transmissions that bounced off the Moon. This program, codenamed "Joe," began making regular observations in August 1949. Within a year, "Joe" was made an official Navy intelligence program, the Passive Moon Relay (PAMOR).

In September 1950, a new parabolic

Parabola

In mathematics, the parabola is a conic section, the intersection of a right circular conical surface and a plane parallel to a generating straight line of that surface...

 antenna

Antenna (radio)

An antenna is an electrical device which converts electric currents into radio waves, and vice versa. It is usually used with a radio transmitter or radio receiver...

 for the PAMOR project was completed at Stump Neck, Maryland. The first tests of this antenna were impressive; the returning signal was of much higher fidelity

Fidelity

"Fidelity" is the quality of being faithful or loyal. Its original meaning regarded duty to a lord or a king, in a broader sense than the related concept of fealty. Both derive from the Latin word fidēlis, meaning "faithful or loyal"....

 than expected. This presented the possibility of using a Moon circuit as a communications circuit. Unfortunately for PAMOR, collecting Soviet radar signals would require a larger antenna. Efforts began to have such an antenna constructed at Sugar Grove, West Virginia

Sugar Grove, West Virginia

Sugar Grove is an American government communications site located in Pendleton County, West Virginia operated by the National Security Agency. According to a in the New York Times, the site intercepts all international communications entering the Eastern United States.The site was first developed...

.

Development

With the PAMOR project requiring a larger antenna, the Stump Neck antenna was pushed into service for testing whether communication via the Moon was possible. This marked the emergence of the Moon Relay as a separate project. Test transmissions between Stump Neck and Washington, DC were carried out; the first satellite transmission of voice occurred on July 24, 1954. These were followed by the first transcontinental test of the system on November 20, 1955; the receiving site was the U.S. Navy Electronics Laboratory in San Diego, California

San Diego, California

San Diego is the eighth-largest city in the United States and second-largest city in California. The city is located on the coast of the Pacific Ocean in Southern California, immediately adjacent to the Mexican border. The birthplace of California, San Diego is known for its mild year-round...

. After corrections to reduce signal loss, the transmissions were extended to Wahiawa, Hawaii.

The Navy received the new system favorably. A Navy contract for the project soon followed the successful tests, and, among other things, it was recommended that American submarines use Moon-reflection paths for communications to shore.

Expansion

The Moon Relay project was soon transferred to the Communications Section of the Radar Division of the Naval Research Laboratory. Under this department, the system was upgraded to use the ultra high frequency

Ultra high frequency

Ultra-High Frequency designates the ITU Radio frequency range of electromagnetic waves between 300 MHz and 3 GHz , also known as the decimetre band or decimetre wave as the wavelengths range from one to ten decimetres...

 (UHF) band. The experimental system was transformed into a fully operational lunar relay system linking Hawaii

Hawaii

Hawaii is the newest of the 50 U.S. states , and is the only U.S. state made up entirely of islands. It is the northernmost island group in Polynesia, occupying most of an archipelago in the central Pacific Ocean, southwest of the continental United States, southeast of Japan, and northeast of...

 with Washington, DC, which became functional in 1959. The new system was officially inaugurated in January 1960, when Chief of Naval Operations

Chief of Naval Operations

The Chief of Naval Operations is a statutory office held by a four-star admiral in the United States Navy, and is the most senior uniformed officer assigned to serve in the Department of the Navy. The office is a military adviser and deputy to the Secretary of the Navy...

 Admiral

Admiral

Admiral is the rank, or part of the name of the ranks, of the highest naval officers. It is usually considered a full admiral and above vice admiral and below admiral of the fleet . It is usually abbreviated to "Adm" or "ADM"...

 Arleigh Burke

Arleigh Burke

Admiral Arleigh Albert '31-knot' Burke was an admiral of the United States Navy who distinguished himself during World War II and the Korean War, and who served as Chief of Naval Operations during the Eisenhower and Kennedy administrations.-Early life and naval career:Burke was born in Boulder,...

 sent a message to Commander, Pacific Fleet

United States Pacific Fleet

The United States Pacific Fleet is a Pacific Ocean theater-level component command of the United States Navy that provides naval resources under the operational control of the United States Pacific Command. Its home port is at Pearl Harbor Naval Base, Hawaii. It is commanded by Admiral Patrick M...

 Felix Stump

Felix Stump

Felix Budwell Stump was an admiral in the United States Navy and Commander, United States Pacific Fleet from July 10, 1953 until July 31, 1958....

 using the system.

The finished system used two sets of transmitters at Annapolis, Maryland

Annapolis, Maryland

Annapolis is the capital of the U.S. state of Maryland, as well as the county seat of Anne Arundel County. It had a population of 38,394 at the 2010 census and is situated on the Chesapeake Bay at the mouth of the Severn River, south of Baltimore and about east of Washington, D.C. Annapolis is...

 and the Opana Radar Site

Opana Radar Site

The Opana Radar Site is a National Historic Landmark and IEEE Milestone that commemorates the first operational use of radar by the United States in wartime, during the attack on Pearl Harbor. It is located off the Kamehameha Highway just inland from the north shore of Oahu, Hawaii, south of...

 in Hawaii and two sets of receivers at Cheltenham, Maryland

Cheltenham, Maryland

Cheltenham is an unincorporated community in Prince George's County, Maryland, United States, adjacent to U.S. Highway 301. It contains a juvenile correctional facility, the Southern Maryland Farmers market, and Maryland Veterans Cemetery, along with many scenic farms and woods. Nearby is the...

 and Wahiawa, Hawaii. It was later expanded to accommodate ship-to-shore transmissions to and from the USS Oxford (AGTR-1)

Technical research ship

Technical research ships were used by the United States Navy during the 1960s to gather intelligence by monitoring the electronic communications of nations in various parts of the world. At the time these ships were active, the mission of the ships was covert and discussion of the true mission was...

.

Results

The Moon Relay system became obsolete in the later 1960s as the Navy implemented its artificial satellite

Satellite

In the context of spaceflight, a satellite is an object which has been placed into orbit by human endeavour. Such objects are sometimes called artificial satellites to distinguish them from natural satellites such as the Moon....

 communication system. However, the information gleaned from the project in fact made the later artificial system possible. Additionally, the equipment used in the Communications Moon Relay project was of much use to U.S. Navy astronomer

Astronomer

An astronomer is a scientist who studies celestial bodies such as planets, stars and galaxies.Historically, astronomy was more concerned with the classification and description of phenomena in the sky, while astrophysics attempted to explain these phenomena and the differences between them using...

s, as they used it to examine the Moon when the Moon was not in a position conducive to radio transmission. Although relatively short-lived, the Moon Relay served as a bridge to modern American military satellite systems.