The new Space Fence was 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, and was intended to replace the Air Force Space Surveillance System, or VHF Fence, that was transferred from the US Navy to the US Air Force in 2004. The shorter wavelength of the S-band Space Fence will allow for the detection of much smaller satellites and debris.[5]
As of 2009[update], data collected from the new Space Fence's sensors was planned to feed into the Joint Space Operations Center Mission System, which is used to track objects orbiting the Earth, monitor space weather, and assess foreign launches. Used by operators at the USAF 614th Air and Space Operations Center 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.[5]
Plans to award the final contract were delayed by the federal government's budget sequestration in early 2013[7] and the AFSSS system was scheduled to be discontinued in October 2013 due to budget cuts.[8]
In 2014, Lockheed Martin awarded a contract for the Space Fence ground structures to General Dynamics. The ground structures include the receive array, cooling equipment, radomes and other buildings. The primary Space Fence system is located on Kwajalein Atoll in the Marshall Islands. The U. S. Space Force declared the system operational on March 28, 2020.[2]
Technical characteristics
The Space Fence will use S-band 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.[1]
Data-sharing agreements
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 and Europe’s Eumetsat weather satellite organization."[1]
^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...