Америкалық орбиталық объектілерді анықтау рада жүйесі

U. S. government radar system to detect orbital objects

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 network, and according to the U. S. Navy was able to detect basketball sized objects at heights up to
The system ceased operation in September 2013. Plans for a new space fence began with sites at the Kwajalein Atoll in the Marshall Islands, along with an option for another radar site in Western Australia. It became operational on March 28, 2020. The operation's headquarters were at Dahlgren, Virginia, and radar stations were spread out across the continental United States at roughly the level of the 33rd parallel north.

The 850th Electronic Systems Group, Electronic Systems Center awarded 3 US$30 million contracts to Lockheed Martin, Northrop Grumman and Raytheon Technologies 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 to the U. S. Air Force in 2004. The shorter wavelength of the S band Space Fence allows for detection of much smaller satellites and debris. Data collected from a new Space Fence's sensors would potentially 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 614th Air and Space Operations Center at Vandenberg Air Force Base, California, 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. and the AFSSS system was scheduled to be discontinued in October 2013 due to budget cuts.

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 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.

A new space fence at Kwajalein Atoll in the Marshall Islands 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.