Sault Ste Marie Air Force Station
Sault Ste Marie Air Force Station (1952-1979) - A Cold War Air Force Radar Station first established as Sault Ste Marie Lashup Radar Site L-21 in 1951 near Sault Ste Marie, Chippewa County, Michigan. Named Sault Ste Marie Air Force Station after the location. Joined the Permanent System with a Permanent ID of LP-66, changed later to just P-66 and to a SAGE System ID of Z-66. Abandoned in 1979.
Became a permanent radar system site P-66 in 1952 and became operational in 1952 as Sault Ste Marie Air Force Station manned by the 753rd AC&W Squadron. The station initially had both a Ground-Control Intercept (GCI) and early warning mission. The early warning mission involved tracking and identifying all aircraft entering their airspace while the GCI mission involved guiding Air Force interceptors to any identified enemy aircraft. Controllers at the station vectored fighter aircraft at the correct course and speed to intercept enemy aircraft using voice commands via ground-to-air radio.
The transition of the manual GCI system to the automated SAGE system began with the installation of the FST-2 coordinate data transmitter and search radar upgrades. The FST-2 equipment digitized the radar returns and transmitted the digital returns to the SAGE direction center. Under the SAGE System, interceptor aircraft were directed to their targets by the direction center computers and controllers, greatly reducing the need for local controllers and equipment at every radar station.
The FST-2 was a very large digital system using vacuum tube technology. Over 6900 vacuum tubes were used in each FST-2 requiring 21 air-conditioned cabinets, 40 tons of air conditioning, 43.5 kva of prime power, and usually a large new addition to the operations building. The FST-2B modification added two more cabinets but with newer solid-state (transistor) technology to process coded responses from aircraft transponders.
SAGE System Operation
The site began operation as a SAGE System site in 1960, initially feeding the K.I. Sawyer SAGE Direction Center DC-14. The search radar was upgraded to an FPS-20A and a second FPS-6 height-finder radar was installed. The station switched to the Custer SAGE Direction Center DC-06 in 1963 and an FPS-35 search radar replaced the FPS-20A. One FPS-6 height-finder was removed and the other was modified to be an FPS-90 that same year. In 1964 an FPS-26A height-finder radar was installed.
Sault Sainte Marie AFS came under Tactical Air Command jurisdiction in October 1979 with the inactivation of Aerospace Defense Command and the formation of ADTAC. Sault Ste Marie AFS and the 753rd were deactivated on 1 Oct 1979.
Gap Filler Radar Sites
Sault Ste Marie Air Force Station AFS was responsible for the maintenance of one remote unattended gap-filler radar site. The gap-filler sites were placed in locations where the main search radar lacked coverage. These sites sent digitized radar target data directly to a direction center. Maintenance teams were dispatched from Sault Ste Marie AFS for regularly scheduled maintenance or when fault indicators suggested the site had problems. The Sault Ste Marie AFS gap-filler radar was located at Grand Marais, MI.
The physical plant of the site was divided into the main site, a cantonment area, a housing area and a radio site. The main site housed the operations buildings, the radar towers, and the backup generators. The cantonment area housed the enlisted barracks, the bachelor officer's quarters, the orderly room, the dining hall, the motor pool and other support buildings. Apart from the main site was a small 16 unit housing area for critical married personnel. A separate Ground to Air Transmitter/Receiver (GATR) radio site housed the radio equipment for directing aircraft intercepts.
Abandoned in Sault Ste Marie, Chippewa County, Michigan.
Visited: 5 Jul 2016