The ''Space Fence'' is a second-generation

space surveillance Space domain awareness is the study and monitoring of satellites orbiting the earth. It involves the detection, tracking, cataloging and identification of artificial objects, i.e. active/inactive satellites, spent rocket bodies, or Space debris, ...

system operated by the

United States Space Force The United States Space Force (USSF) is the space service branch of the U.S. Armed Forces, one of the eight U.S. uniformed services, and the world's only independent space force. Along with its sister branch, the U.S. Air Force, the Space ...

in order to track

artificial satellites 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 radioisotope ...

and

space debris Space debris (also known as space junk, space pollution, space waste, space trash, or space garbage) are defunct human-made objects in space—principally in Earth orbit—which no longer serve a useful function. These include derelict spacec ...

Earth orbit Earth orbits the Sun at an average distance of 149.60 million km (92.96 million mi) in a counterclockwise direction as viewed from above the Northern Hemisphere. One complete orbit takes days (1 sidereal year), during which time E ...

. Contracts were issued for development and construction in 2014, and the Space Fence was expected to be operational in the fourth quarter of 2019.Indian anti-satellite test proves early test for Space Fence
by Debra Werner — April 11, 2019, SpaceNews.com, ''...Still in testing mode, the U.S. Air Force Space Fence on Kwajalein Atoll detected India’s March 27 anti-satellite test and issued a break-up alert...The Air Force is scheduled to begin initial operation...in the fourth quarter of this year...'' The budget is (FY15). The initial space fence facility was to be located at

Kwajalein Atoll Kwajalein Atoll (; Marshallese: ) is part of the Republic of the Marshall Islands (RMI). The southernmost and largest island in the atoll is named Kwajalein Island, which its majority English-speaking residents (about 1,000 mostly U.S. civilia ...

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 Inte ...

, 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 t ...

. The

U.S. Space Force The United States Space Force (USSF) is the space service branch of the U.S. Armed Forces, one of the eight U.S. uniformed services, and the world's only independent space force. Along with its sister branch, the U.S. Air Force, the Space ...

declared the system operational on March 28, 2020.

History

AFSPC Unveils Space Fence Model (3834946)

The initial plans to upgrade the legacy

Air Force Space Surveillance System 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 orbital objects passing over America. It is a component of the U.S. space surveillance n ...

were made in 2009. The USAF 850th Electronic Systems Group, Electronic Systems Center awarded three $30-million study contracts to

Lockheed Martin The Lockheed Martin Corporation is an American aerospace, arms, defense, information security, and technology corporation with worldwide interests. It was formed by the merger of Lockheed Corporation with Martin Marietta in March 1995. It ...

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 tech ...

, and

Raytheon 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 capitali ...

on 11 June 2009. The new ''Space Fence'' was envisioned to be a system of two or three

S-band The S band is a designation by the Institute of Electrical and Electronics Engineers (IEEE) for a part of the microwave radio band, band of the electromagnetic spectrum covering frequency, frequencies from 2 to 4 gigahertz (GHz). Thus it c ...

ground-based radars designed to perform uncued detection, tracking and accurate measurement of orbiting space objects, and was intended to replace the Air Force Space Surveillance System, or VHF Fence, that was transferred from the

US 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 ...

to the

US 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 Sig ...

in 2004. The shorter wavelength of the S-band ''Space Fence'' will allow for the detection of much smaller satellites 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 February 10, 2009 collision of the

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 Cosmos 2251 communications satellites, which added hundreds more pieces of debris in orbit, highlighted the need for more precise tracking of space objects. , data collected from the new ''Space Fence's'' sensors was planned to 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, 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 USAF

614th Air and Space Operations Center The 614th Air Operations Center (614 AOC) was a space operations center of the United States Space Force's Space Operations Command. It served as the core of the Combined Space Operations Center, as well as serving as the Space Force's primary f ...

at Vandenberg Air Force Base, Calif., 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 were delayed by the federal government's

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. In 2014,

awarded a contract for the Space Fence ground structures to

General Dynamics General Dynamics Corporation (GD) is an American publicly traded, aerospace and defense corporation headquartered in Reston, Virginia. As of 2020, it was the fifth-largest defense contractor in the world by arms sales, and 5th largest in the Uni ...

. The ground structures include the receive array, cooling equipment, radomes and other buildings. The primary Space Fence system, procured by the Air Force will be located on

in the Marshall Islands. The U. S. Space Force declared the system operational on March 28, 2020.

Technical characteristics

The Space Fence will use

radar and will track a larger number of small objects than previous space radars: "about 200,000 objects and make 1.5 million observations per day, about 10 times the number" made by existing or recently retired US assets.

Data-sharing agreements

, the

United States Strategic Command United States Strategic Command (USSTRATCOM) is one of the eleven unified combatant commands in the United States Department of Defense. Headquartered at Offutt Air Force Base, Nebraska, USSTRATCOM is responsible for strategic nuclear deter ...

had "announced data-sharing agreements with at least seven countries and 44 companies, but he details ofthose agreements have otbeen made public" and it is unclear how much of the new Space Fence data will be shared. Countries with space situational awareness data-sharing agreements in place with the USAF include Australia, Japan, Italy, Canada, France, South Korea, and the United Kingdom. It also "has agreements with the

European Space Agency , owners = , headquarters = Paris, Île-de-France, France , coordinates = , spaceport = Guiana Space Centre , seal = File:ESA emblem seal.png , seal_size = 130px , image = Views in the Main Control Room (120 ...

and Europe’s

Eumetsat The European Organization for the Exploitation of Meteorological Satellites (EUMETSAT) is an intergovernmental organisation created through an international convention agreed by a current total of 30 European Member States. EUMETSAT's primary ...

weather satellite organization."

Predecessor system

A previous system used by the USAF for the same purpose was the

, which ceased operation in September 2013.

References

{{Lockheed Martin 2020 establishments in the Marshall Islands Equipment of the United States Space Force Lockheed Martin Radar networks Raytheon Company United States Space Surveillance Network