20th Space Surveillance Squadron
The 20th Space Surveillance Squadron, Site C-6, Eglin Air Force Base, FL, tracks more than 16,000 near-Earth and deep-space objects. Additionally the squadron has four Ground-based Electro-Optical Deep Space Surveillance detachments assigned to it: 20 SPSS, Detachment 1, Socorro NM, 20 SPSS, Detachment 2, Diego Garcia, 20 SPSS, Detachment 3, Maui HI, and 20 SPSS, Detachment 4, Kwajalein Atoll in the Marshall Islands. The squadron is a geographically separated unit of Space Delta 2, Peterson Space Force Base, CO.
MISSION
The 20th SPSS executes multiplatform, tactical space domain characterization and responsiveness to achieve Space Delta 2 and USSPACECOM warfighting intent.
FEATURES
The 20th SPSS Site C-6 operates and maintains the AN/FPS-85 Phased Array Radar, the only phased array radar dedicated to tracking more than 16,000 near-earth and deep-space objects. It is one of 29 sensors that comprise the global Space Surveillance Network, or SSN, and is the only phased array radar dedicated to space surveillance. It collects more than 16 million observations of satellites per year, accounting for 30 percent of the SSN's total workload. The unique aspect of this radar is the phased array antenna technology. Unlike a mechanical radar, which must be physically aimed at an object in space to track and observe it, the phased array antenna is steered electronically by controlling the timing, or phase, of incoming and outgoing signals. This increases capabilities and decreases response time which allows near simultaneous tracking of multiple targets throughout the system's area of coverage. The AN/FPS-85 can detect, track and identify any object down to the size of a basketball at a distance of more than 22,000 nm, and can track up to 200 satellites simultaneously.
In addition to operating and maintaining the phased array radar on site, the 20th SPSS now manages operations for the Space Fence radar, which is geographically located on Kwajalein Atoll in the Marshall Islands. Space Fence is now the world’s most advanced radar, and provides uncued detection of nanosatellites and debris as small as 10 centimeters due to its equatorial location and the Gallium Nitride (GaN) powered S-band radars that make up the fence. GaN transistors can operate at higher temperatures, frequencies and voltages, making them the highest efficiency amplifiers for the program’s ultimate function. In addition to tracking items, Space Fence monitors movement from low-Earth orbit (altitude of 400 to 1,200 miles) to geosynchronous orbit (altitude of 22,236 miles that allows satellites to match Earth’s orbit) as well as the spacing of objects.
The 20th SPSS AN/FPS-85 Phased Array Space Surveillance Radar and Space Fence dramatically increase the quality of known positional accuracy for space objects and provide actionable space situational awareness for USSPACECOM's Space Domain Awareness and human spaceflight safety.
HISTORY
Radar construction began in October 1962 and testing was scheduled for May 1965; but four months prior, the building and all equipment were destroyed in a fire caused by arcing electrical equipment. The Air Force took ownership of the site in September 1968 with the 20th Surveillance Squadron, or 20th SURS, as the primary operator. Space operations began in February 1969. Initially designed to track satellites, new software installed in 1975 enabled the unit to track submarine launched ballistic missiles, or SLBMs. This became the unit's primary mission, while space surveillance became secondary. From 1971 to 1984 the 20 SURS served as the Alternate Space Surveillance Center, providing computational support to the Space Surveillance Center at Cheyenne Mountain AS, Colorado. If the need arose, the squadron could assume command and control of worldwide SSN.
In 1979, the 20 SURS was renamed the 20th Missile Warning Squadron, or 20th MWS, and four years later, with deactivation of Strategic Air Command, the squadron was transferred to Air Force Space Command. During this time, the AN/FPS-85 was the proving ground for development of phased array radars designed specifically for early warning of SLBM attacks. These PAVE Phased Array Warning System radars assumed missile warning responsibilities from the 20th MWS and in 1987, the unit returned to its original mission of space surveillance with a corresponding name change to the 20th Space Surveillance Squadron. In February 2003, the unit was again re-designated, this time as the 20th SPCS. In April 2016, three Ground-based Electro-Optical Deep Space Surveillance (GEODSS) detachments were assigned under the 20th SPCS making this squadron the Department of Defense’s premiere space surveillance unit, responsible for a vast majority of all Deep Space object observations. 60 years after operational acceptance, the unit's mission is more robust and critical than ever with the addition of yet another detachment, weapons system, and name change back to the 20th Space Surveillance Squadron in a nod to heritage in 2022.
LOCATION
20 SPSS is located on site C-6 which is part of Eglin Air Force Base’s vast range complex. The site is located approximately 2 miles north of Highway-20 near Freeport, Florida.
Updated April 2022