Andover Earth Station
Encyclopedia
Satellite earth station
A ground station, earth station, or earth terminal is a terrestrial terminal station designed for extraplanetary telecommunication with spacecraft, and/or reception of radio waves from an astronomical radio source. Ground stations are located either on the surface of the Earth, or within Earth's...
s, located at Andover
Andover, Maine
Andover is a town in Oxford County, Maine, United States. The population was 864 at the 2000 census. Set among mountains and crossed by the Appalachian Trail, Andover is home to the Andover Earth Station and Lovejoy Covered Bridge.-History:...
(44°37′58.0"N 70°41′57.0"W) in the US state of Maine
Maine
Maine is a state in the New England region of the northeastern United States, bordered by the Atlantic Ocean to the east and south, New Hampshire to the west, and the Canadian provinces of Quebec to the northwest and New Brunswick to the northeast. Maine is both the northernmost and easternmost...
. It was built by AT&T
AT&T
AT&T Inc. is an American multinational telecommunications corporation headquartered in Whitacre Tower, Dallas, Texas, United States. It is the largest provider of mobile telephony and fixed telephony in the United States, and is also a provider of broadband and subscription television services...
to communicate with the Telstar 1 satellite, the first direct relay communications satellite
Communications satellite
A communications satellite is an artificial satellite stationed in space for the purpose of telecommunications...
. It provided the first experimental satellite telephone and television service between North America and Europe. It was also used with the Relay satellite. The station was dismantled in the 1990s.
The location was selected by AT&T
AT&T
AT&T Inc. is an American multinational telecommunications corporation headquartered in Whitacre Tower, Dallas, Texas, United States. It is the largest provider of mobile telephony and fixed telephony in the United States, and is also a provider of broadband and subscription television services...
in December 1960. The main factors were the topography
Topography
Topography is the study of Earth's surface shape and features or those ofplanets, moons, and asteroids...
(set in the Western Maine Mountains
Western Maine Mountains
The Western Maine Mountains region spans most of Maine's western border with New Hampshire. A small part of the scenic White Mountain National Forest is located in this area. This is essentially all of Oxford County and northern York County and Cumberland Counties. Notable towns include Bethel,...
), and the radio interference signal level. Other factors included a location in the Northeastern United States
Northeastern United States
The Northeastern United States is a region of the United States as defined by the United States Census Bureau.-Composition:The region comprises nine states: the New England states of Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island and Vermont; and the Mid-Atlantic states of New...
to give a short great circle
Great circle
A great circle, also known as a Riemannian circle, of a sphere is the intersection of the sphere and a plane which passes through the center point of the sphere, as opposed to a general circle of a sphere where the plane is not required to pass through the center...
path to Western Europe
Western Europe
Western Europe is a loose term for the collection of countries in the western most region of the European continents, though this definition is context-dependent and carries cultural and political connotations. One definition describes Western Europe as a geographic entity—the region lying in the...
, it was located close enough to existing transcontinental radio relay television and telephone routes to facilitate interconnection. In addition, the site had to be large enough to accommodate an antenna
Horn antenna
A horn antenna or microwave horn is an antenna that consists of a flaring metal waveguide shaped like a horn to direct the radio waves. Horns are widely used as antennas at UHF and microwave frequencies, above 300 MHz...
structure and control building, and if necessary, provide room for expansion.
Land was purchased in January 1961, and construction of the complex began on May 1. Building construction was completed and the equipment was installed in February 1962. The Ground Station was operational in the Spring of 1962. AT&T and Bell Labs
Bell Labs
Bell Laboratories is the research and development subsidiary of the French-owned Alcatel-Lucent and previously of the American Telephone & Telegraph Company , half-owned through its Western Electric manufacturing subsidiary.Bell Laboratories operates its...
initiated, funded, constructed and took the leadership to make this project possible.
The radio transmitter aboard Telstar was very low-powered compared to modern communication satellites, with a power of only 14 watts, and transmitted through an omnidirectional antenna
Omnidirectional antenna
In radio communication, an omnidirectional antenna is an antenna which radiates radio wave power uniformly in all directions in one plane, with the radiated power decreasing with elevation angle above or below the plane, dropping to zero on the antenna's axis. This radiation pattern is often...
. So the ground antennas that communicated with it had to be huge. The Andover Earth Station was equipped with a giant horn antenna
Horn antenna
A horn antenna or microwave horn is an antenna that consists of a flaring metal waveguide shaped like a horn to direct the radio waves. Horns are widely used as antennas at UHF and microwave frequencies, above 300 MHz...
, 7 stories high and weighing 340 tons. To protect it from bad weather, a radome
Radome
A radome is a structural, weatherproof enclosure that protects a microwave or radar antenna. The radome is constructed of material that minimally attenuates the electromagnetic signal transmitted or received by the antenna. In other words, the radome is transparent to radar or radio waves...
made of Dacron
Polyethylene terephthalate
Polyethylene terephthalate , commonly abbreviated PET, PETE, or the obsolete PETP or PET-P, is a thermoplastic polymer resin of the polyester family and is used in synthetic fibers; beverage, food and other liquid containers; thermoforming applications; and engineering resins often in combination...
covered the antenna. It was 160 feet (49 m) high, 210 feet (64 m) wide and weighed 30 tons. Since the satellite was not in a geosynchronous orbit
Geosynchronous orbit
A geosynchronous orbit is an orbit around the Earth with an orbital period that matches the Earth's sidereal rotation period...
like modern communication satellites, it passed overhead quickly, and the giant antenna had to be precisely steerable to track the satellite as it moved across the sky.
Telstar was launched on July 10, 1962 from the Cape Canaveral Air Force Station
Cape Canaveral Air Force Station
Cape Canaveral Air Force Station is an installation of the United States Air Force Space Command's 45th Space Wing, headquartered at nearby Patrick Air Force Base. Located on Cape Canaveral in the state of Florida, CCAFS is the primary launch head of America's Eastern Range with four launch pads...
and went into orbit at 4:46 a.m. The engineers at the Andover Earth Station would have to wait 15 hours for the 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....
, travelling at a rate of 5 miles per second (8 km/s), 3,000 miles (4,800 km) above the earth to reach within their "view". The engineers successfully sent a signal to Telstar, which amplified it 10 billion times and relayed it back to Andover.
Eugene F. O'Neill, Telstar Project Director and IEEE
Institute of Electrical and Electronics Engineers
The Institute of Electrical and Electronics Engineers is a non-profit professional association headquartered in New York City that is dedicated to advancing technological innovation and excellence...
Fellow, oversaw the success of this project at Andover. He noted that one of the challenges was pointing an extremely sharp beam very accurately at the satellite. At 7:17 p.m. he announced "We've acquired Telstar!" At 7:31 p.m. an American flag
Flag of the United States
The national flag of the United States of America consists of thirteen equal horizontal stripes of red alternating with white, with a blue rectangle in the canton bearing fifty small, white, five-pointed stars arranged in nine offset horizontal rows of six stars alternating with rows...
at Andover appeared on the television screen. Then at 7:47 p.m. engineers at Andover received word that the French site, Pleumeur-Bodou, had received the television picture.
The Large radome was torn down and land returned to nature in the mid-1990s.