Raytheon AN/FPS-120 Solid State Phased Array Radar at Thule with greater radar capabilities than the FPS-115 PAVE PAWS radars
Raytheon AN/FPS-126 Solid State Phased Array Radar at Fylingdales with three faces for 360 degree coverage
Raytheon AN/FPS-120 Solid State Phased Array Radar using an older antenna from the 1987 PAVE PAWS EWR in Texas
After the Fylingdales BMEWS radars had been replaced by Raytheon/Cossor AeroSpace and Control Data Corporation at a cost of US $100M, in February 1995 the "missile warning center at Cheyenne Mountain AS undergoing a $450 million upgrade program". The entire SSPARS became operational on January 31, 2001 when the "SSPARS Site" at Clear AFS had Initial Operational Capability. The Clear AN/FPS-120 was subsequently "upgraded to the AN/FPS-123 model" SSPA Radar, and the SSPARS was modified in the Early Warning Radar Service Life Extension Program The US approved sale of an AN/FPS-115 to Taiwan in 2000 and it was introduced in 2006.
The Solid State Phased Array Radar System began replacing PAVE PAWS when the first AN/FPS-115 face was taken off-line for the radar upgrade. New AN/FPS-123 Early Warning Radars became operational in and in each base's existing PAVE PAWS "Scanner Building". The UK and Alaska BMEWS stations became SSPARS radar stations when their respective AN/FPS-126 radar and 2001 AN/FPS-120 became operational. In 2007, 100 owners/trustees of amateur radio repeaters near AN/FPS-123 radars were notified to lower their power output to mitigate interference, and AN/FPS-123s were part of the Air Force Space Surveillance System by 2009. BAE Systems began a 2007 contract for SSPARS maintenance. The SSPARS radar electronics was subsequently upgraded, e.g., the Beale radar and the Fylingales FPS-126 each became an AN/FPS-132 Upgraded Early Warning Radar by Raytheon. The Beale AN/FPS-123 was upgraded to a Raytheon AN/FPS-132 with capabilities to operate in the Ground-based Midcourse Defense ABM system—the Beale UEWR included "Avionics", "T/R modules", "FEX/TTG", "BSG", "Signal Processor", and other changes. After additional UEWR installations for GMD at Thule Site J and the UK, a 2012 ESD/XRX Request for Information for replacement, and remote operation, of the remaining "PAVE PAWS/BMEWS/PARCS systems" at Cape Cod, Alaska, and North Dakota was issued. The Alaska AN/FPS-132 was contracted in fall 2012 and the Cape Cod installation in 2013.