The AN/FPS-133 Air Force Space Surveillance System, colloquially known as the Space Fence, was a
U.S. government multistatic radar system built to detect
orbit
In celestial mechanics, an orbit is the curved trajectory of an object such as the trajectory of a planet around a star, or of a natural satellite around a planet, or of an artificial satellite around an object or position in space such as ...
al objects passing over
America. It is a component of the
U.S. space surveillance network, and according to the
U.S. Navy
The United States Navy (USN) is the maritime service branch of the United States Armed Forces and one of the eight uniformed services of the United States. It is the largest and most powerful navy in the world, with the estimated tonnage o ...
was able to detect basketball sized () objects at heights up to .
The system ceased operation in September 2013. Plans for a
new space fence are underway with sites at the
Kwajalein Atoll in the
Marshall Islands
The Marshall Islands ( mh, Ṃajeḷ), officially the Republic of the Marshall Islands ( mh, Aolepān Aorōkin Ṃajeḷ),'' () is an independent island country and microstate near the Equator in the Pacific Ocean, slightly west of the Intern ...
, along with an option for another radar site in
Western Australia
Western Australia (commonly abbreviated as WA) is a state of Australia occupying the western percent of the land area of Australia excluding external territories. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to th ...
.
The operation's headquarters were at
Dahlgren, Virginia
Dahlgren is an unincorporated community and census-designated place (CDP) in King George County, Virginia, United States. The population was 2,946 at the time of the 2020 census, up from 2,653 at the 2010 census, and up from 997 in 2000.
History ...
, and
radar station
Radar is a detection system that uses radio waves to determine the distance (''ranging''), angle, and radial velocity of objects relative to the site. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, wea ...
s were spread out across the
continental United States
The contiguous United States (officially the conterminous United States) consists of the 48 adjoining U.S. states and the Federal District of the United States of America. The term excludes the only two non-contiguous states, Alaska and Hawaii ...
at roughly the level of the
33rd parallel north
The 33rd parallel north is a circle of latitude that is 33 degrees north of the Earth's equatorial plane. It is approximate at the midpoint between the equator (0 degrees) and the Arctic Circle (66.6 degrees North Latitude.) It crosses North ...
.
Description
There were three
transmitter
In electronics and telecommunications, a radio transmitter or just transmitter is an electronic device which produces radio waves with an antenna. The transmitter itself generates a radio frequency alternating current, which is applied to the ...
sites in the system:
* 216.983
MHz
The hertz (symbol: Hz) is the unit of frequency in the International System of Units (SI), equivalent to one event (or cycle) per second. The hertz is an SI derived unit whose expression in terms of SI base units is s−1, meaning that one he ...
at
Lake Kickapoo, Texas () (Master transmitter)
* 216.970 MHz at
Gila River, Arizona ()
* 216.990 MHz at
Jordan Lake, Alabama ()
The master transmitter at
Lake Kickapoo
Lake Kickapoo is a reservoir located on the North Fork Little Wichita River in the Red River Basin of Archer County, Texas. It is neighbored by Archer City, Texas (population of 1,834) and Wichita Falls, Texas (population of 104,553) which resid ...
was said to be the most powerful
continuous wave (CW) station in the world, at 768 kW
radiated power on 216.97927 MHz.
When the system became operational in 1961, the original frequency was 108.50 MHz (just above the FM broadcast band). In 1965, the "Fence" system was modernized with the operating frequency doubled to 216.98 MHz (just above Channel 13 in the VHF TV broadcast band) to obtain higher resolution and to locate smaller objects. This frequency was used until the Fence was decommissioned in 2013. Fill-in transmitter sites at Gila River and Jordan Lake used offset frequencies listed above from the early 1990s to 2013 to help better detect which transmitter "illuminated" an object in space, as multiple transmitters could have illuminated the same object at the same time. Overhead imagery (see coordinates given above) of the
Gila River and
Jordan Lake sites shows the original design at the lower frequency.
There were six receiving stations:
*
San Diego, California
San Diego ( , ; ) is a city on the Pacific Ocean coast of Southern California located immediately adjacent to the Mexico–United States border. With a 2020 population of 1,386,932, it is the eighth most populous city in the United Stat ...
()
*
Elephant Butte, New Mexico
Elephant Butte is a city in Sierra County, New Mexico, United States, located near Elephant Butte Reservoir and Elephant Butte Lake State Park. The population was 1,431 at the time of the 2010 census.
History
Elephant Butte was named from E ...
()
*
Red River, Arkansas ()
*
Silver Lake, Mississippi ()
*
Hawkinsville, Georgia
Hawkinsville is a city in and the county seat of Pulaski County, Georgia, United States. The population was 4,589 at the 2010 census.
Hawkinsville is known as the "Harness Horse Capital" of Georgia. The Lawrence Bennett Harness Horse Racing f ...
()
*
Tattnall, Georgia ()
The following receiving stations were placed in cold storage in April 2013:
*
Silver Lake, Mississippi ()
*
Tattnall, Georgia ()
The receiving stations at
Elephant Butte and
Hawkinsville
Hawkinsville is a city in and the county seat of Pulaski County, Georgia, Pulaski County, Georgia (U.S. state), Georgia, United States. The population was 4,589 at the 2010 census.
Hawkinsville is known as the "Harness Horse Capital" of Georgia. ...
were considered to be "High Altitude" stations with longer and more complex antenna systems that are designed to see targets at higher altitudes than the other four receiving stations.
History
Author
Curtis Peebles notes that the original "Space Fence" or Space Surveillance System began operations in 1959.
The system predated the formation of
NORAD and was known as the U.S. Navy Space Surveillance System (or SPASUR or NAVSPASUR). From 1960 until the early 1990s the system was used in conjunction with a network of
Baker-Nunn cameras that could see "an object the size of a basketball at ".
The system was formerly operated by the
U.S. Navy
The United States Navy (USN) is the maritime service branch of the United States Armed Forces and one of the eight uniformed services of the United States. It is the largest and most powerful navy in the world, with the estimated tonnage o ...
for
NORAD from 1961 until October 2004. Initially independent as NAVSPASUR, it was run by
Naval Space Command
The Naval Space Command (NSC) was a military command of the United States Navy and former component command of United States Space Command. It was headquartered at Dahlgren, Virginia, and began operations on 1 October 1983. Naval Space Command us ...
from 1993, and finally by Naval Network and Space Operations Command from 2002 until command was passed to the
U.S. Air Force
The United States Air Force (USAF) is the air service branch of the United States Armed Forces, and is one of the eight uniformed services of the United States. Originally created on 1 August 1907, as a part of the United States Army Sign ...
20th Space Control Squadron
The 20th Space Surveillance Squadron (20 SPSS) is a Space Delta 2 unit located at Eglin Air Force Base, Florida with the mission to execute multiplatform, tactical space warfighting domain characterization, recognition, and responsiveness to a ...
on 1 October 2004.
In 2009, the operations and maintenance contract for the day-to-day management and operation of the Fence was awarded to Five Rivers Services,
LLC, based in
Colorado Springs, Colorado. On 30 September 2011, Five Rivers Services was awarded a US$7,022,503 firm fixed price with cost reimbursable line items contract modification to manage, operate, maintain, and logistically support the nine Air Force Space Surveillance System field stations, presumably for Fiscal Year 2012.
Plans for system upgrade: 2009 — 2012
The 850th Electronic Systems Group,
Electronic Systems Center
The Electronic Systems Center was a product center of Air Force Materiel Command (AFMC) headquartered at Hanscom Air Force Base, Massachusetts. Its mission was to develop and acquire command and control, communications, computer, and intellige ...
awarded 3 US$30-million contracts to
Lockheed Martin,
Northrop Grumman
Northrop Grumman Corporation is an American multinational aerospace and defense technology company. With 90,000 employees and an annual revenue in excess of $30 billion, it is one of the world's largest weapons manufacturers and military techn ...
and
Raytheon Technologies
Raytheon Technologies Corporation is an American multinational aerospace and defense conglomerate headquartered in Arlington, Virginia. It is one of the largest aerospace and defense manufacturers in the world by revenue and market capitaliza ...
on 11 June 2009.
A new Space Fence is envisioned to be a system of two or three
S-band ground-based radars designed to perform uncued detection, tracking and accurate measurement of orbiting space objects. The Space Fence is intended to replace the Air Force Space Surveillance System, or VHF Fence, that was transferred from the
U.S. Navy
The United States Navy (USN) is the maritime service branch of the United States Armed Forces and one of the eight uniformed services of the United States. It is the largest and most powerful navy in the world, with the estimated tonnage o ...
to the
U.S. Air Force
The United States Air Force (USAF) is the air service branch of the United States Armed Forces, and is one of the eight uniformed services of the United States. Originally created on 1 August 1907, as a part of the United States Army Sign ...
in 2004. The shorter
wavelength
In physics, the wavelength is the spatial period of a periodic wave—the distance over which the wave's shape repeats.
It is the distance between consecutive corresponding points of the same phase on the wave, such as two adjacent crests, t ...
of the S-band Space Fence allows for detection of much smaller
satellite
A satellite or artificial satellite is an object intentionally placed into orbit in outer space. Except for passive satellites, most satellites have an electricity generation system for equipment on board, such as solar panels or radioi ...
s and
debris
Debris (, ) is rubble, wreckage, ruins, litter and discarded garbage/refuse/trash, scattered remains of something destroyed, or, as in geology, large rock fragments left by a melting glacier, etc. Depending on context, ''debris'' can refer to ...
.
The
10 February 2009, collision of a U.S.
Iridium communications satellite (
Iridium 33
Iridium 33 was a communications satellite launched by Russia for Iridium Communications. It was launched into low Earth orbit from Site 81/23 at the Baikonur Cosmodrome at 01:36 UTC on 14 September 1997, by a Proton-K rocket with a Block DM2 up ...
) and a
Russia
Russia (, , ), or the Russian Federation, is a transcontinental country spanning Eastern Europe and Northern Asia. It is the largest country in the world, with its internationally recognised territory covering , and encompassing one-eig ...
n
Cosmos 2251 communications satellite, which added hundreds more pieces of debris to the
atmosphere, highlighted the need for more precise
tracking of space objects.
Data collected from a new Space Fence's
sensors
A sensor is a device that produces an output signal for the purpose of sensing a physical phenomenon.
In the broadest definition, a sensor is a device, module, machine, or subsystem that detects events or changes in its environment and sends ...
would potentially feed into the
Joint Space Operations Center
The Combined Space Operations Center (CSpOC) is a U.S.–led multinational space operations center that provides command and control of space forces for United States Space Command's Combined Force Space Component Command. The CSpOC is located at ...
Mission System, which is used to track objects orbiting the
Earth
Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surfa ...
, monitor
space weather
Space weather is a branch of space physics and aeronomy, or heliophysics, concerned with the time varying conditions within the Solar System, including the solar wind, emphasizing the space surrounding the Earth, including conditions in the ...
and assess foreign launches. Used by operators at the
614th Air and Space Operations Center at
Vandenberg Air Force Base Vandenberg may refer to:
* Vandenberg (surname), including a list of people with the name
* USNS ''General Hoyt S. Vandenberg'' (T-AGM-10), transport ship in the United States Navy, sank as an artificial reef in Key West, Florida
* Vandenberg Sp ...
,
California
California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the m ...
, the 614 AOC's 24-hour-a-day, seven-day-a-week support provides vigilance of global and theater operations and equips the Joint Functional Component Command for space operations with the tools to conduct command and control of space forces.
Plans to award the final contract had been stalled by
U.S.
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territori ...
budget sequestration
Budget sequestration is a provision of United States law that causes an across-the-board reduction in certain kinds of spending included in the federal budget. Sequestration involves setting a hard cap on the amount of government spending with ...
in early 2013 and the AFSSS system was scheduled to be discontinued in October 2013 due to budget cuts.
2013 Shutdown
On 1 August 2013, General
William L. Shelton, commander of Air Force Space Command, directed that the Air Force Space Surveillance System (AFSSS) be closed and all sites vacated effective 1 October 2013. The main advantage of the system was its ability to provide uncued data on new objects as opposed to tracking objects based on existing information. However, the system was also said to be inherently inaccurate due to its dated design. Alternate operating modes for radars at
Cavalier Space Force Station and
Eglin AFB
Eglin Air Force Base is a United States Air Force (USAF) base in the western Florida Panhandle, located about southwest of Valparaiso in Okaloosa County.
The host unit at Eglin is the 96th Test Wing (formerly the 96th Air Base Wing). The 9 ...
were devised to fulfill the mission to provide uncued data for new objects. Shelton also noted the confusion between the planned new S-band space fence and the old UHF AFSSS, which was commonly called the "space fence". The AFSSS was turned off September first. "It appears they pulled the plug at 00:00
UTC (6 a.m. Local MDT) on September 1st", reports engineer Stan Nelson, who was monitoring the radar using an antenna in Roswell. The radar's final echoes came from a Russian satellite and a sporadic meteor". The shutdown only affects the original Space Fence, not the new one contracted to be built by
Lockheed Martin for deployment in
Australia and the
Marshall Islands
The Marshall Islands ( mh, Ṃajeḷ), officially the Republic of the Marshall Islands ( mh, Aolepān Aorōkin Ṃajeḷ),'' () is an independent island country and microstate near the Equator in the Pacific Ocean, slightly west of the Intern ...
.
New space fence
A
new space fence at
Kwajalein Atoll in the
Marshall Islands
The Marshall Islands ( mh, Ṃajeḷ), officially the Republic of the Marshall Islands ( mh, Aolepān Aorōkin Ṃajeḷ),'' () is an independent island country and microstate near the Equator in the Pacific Ocean, slightly west of the Intern ...
was declared operational on March 27, 2020.
In 2014
Lockheed Martin won the contract to build the new
S band space fence system at Kwajelein with an option for another radar site in
Western Australia
Western Australia (commonly abbreviated as WA) is a state of Australia occupying the western percent of the land area of Australia excluding external territories. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to th ...
.
See also
*
GRAVES
A grave is a location where a dead body (typically that of a human, although sometimes that of an animal) is buried or interred after a funeral. Graves are usually located in special areas set aside for the purpose of burial, such as grave ...
, in
France
France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of overseas regions and territories in the Americas and the Atlantic, Pacific and Indian Oceans. Its metropolitan area ...
*
Krona space object recognition station
Krona space object recognition station ( rus, Радиооптический комплекс распознавания космических объектов «Крона», Radiooptichesky Kompleks raspoznavaniya kosmicheskikh obektov "Krona ...
and
Krona-N, in
Russia
Russia (, , ), or the Russian Federation, is a transcontinental country spanning Eastern Europe and Northern Asia. It is the largest country in the world, with its internationally recognised territory covering , and encompassing one-eig ...
References
External links
Air Force uses invisible fence to protect skies- an article about the Gila River, Arizona installation - InMaricopa Magazine, March 10, 2012
20th Space Control Squadron, Det 1- Air Force Fact sheet about the Alternate Space Control Center and the AN/FPS-133 surveillance fence radar
at the
FAS website
Rural site part of USA's oldest sat-tracking systemfrom
USA Today
''USA Today'' (stylized in all uppercase) is an American daily middle-market newspaper and news broadcasting company. Founded by Al Neuharth on September 15, 1982, the newspaper operates from Gannett's corporate headquarters in Tysons, Virgi ...
Tattnall Space Surveillance Station shut down due to sequestration April 18, 2013, Ronald E. McCall, The Tatnall Journal
- Maxwell-Gunter AFB
* http://www.fiveriversservices.com/ - former contractor for AFSSS
{{USAF system codes
Radar networks
Radars of the United States Air Force
United States Space Surveillance Network
Military equipment introduced in the 1960s