AN/FPS-108 Cobra Dane

The AN/FPS-108 Cobra Dane was a large L-band, single-faced, phased-array radar which was developed by Raytheon in 1976, during the Cold War. The main function of the AN/FPS-108 was to provide intelligence on Soviet test missiles fired at the Kamchatka peninsula from locations in southwestern Russia. Operating in the 1215-1400 MHz band, the Cobra Dane originally utilized a Control Data Corporation Cyber 74 mainframe computer for data processing. Data from the radar was sent to the North American Aerospace Defense Command (NORAD) at Cheyenne Mountain Operations Center. The radar antenna face of the building measured about 90 feet in diameter and contained some 16,000 elements.

The AN/FPS-108 system provided 120-degree coverage of a 2,000-mile corridor that spanned the eastern Russian peninsula and northern Pacific Ocean. Its digital data and voice communication systems interfaced with the National Air Intelligence Center (NAIC) and the North American Aerospace Defense Command (NORAD). Aside from determining Soviet missile capabilities, Cobra Dane had the dual secondary role of tracking space objects and providing ballistic missile early warning as this L-band radar had a range of 2,000 miles and could track space objects as far as 25,000 miles away. A modernization effort extended the Cobra Dane’s operational life by 15 years and enhanced its performance to meet upgraded mission requirements. The upgrade featured new hardware, including the signal and data processing system, receivers and displays, and a transition to Ada software.