- Ballistic Missile Early Warning System
United States Air ForceBallistic Missile Early Warning System (BMEWS) was the first operational ballistic missiledetection radar. The original system was built in 1959 and could provide long-range warning of a ballistic missile attack over the polar regionof the northern hemisphere. They also provided satellite tracking data. The three installations are:
*Site I- A
United States Air Forcefacility at Thule Air Base, Greenland,
(coord|76.569|N|68.318|W) operated by the 12th Space Warning Squadron. [ [http://www.thule.af.mil/ Thule AB, Greenland] ]
*Site II - A second USAF facility at
Clear Air Force Station, Alaska,
(coord|64|17|19|N|149|11|22|W|region:US) [https://www.clear.af.mil/mission.htm Clear AFS Mission] See alternate Clear AFS site]
*Site III - A
Royal Air Forcefacility of Fylingdales, in the United Kingdom
The three facilities operated their original 1950s vintage radars for more than four decades, but all have been upgraded with more modern
phased array radars. The facility at Clear Air Force Station was the last to be upgraded, and now operates a PAVE PAWSradar that was moved from Texas in 2001. [ [http://www.fas.org/spp/military/program/track/pavepaws.htm Pave PAWS System] ] Information received from the BMEWS radars is forwarded to Cheyenne Mountain Air Station, Coloradowhere it is coordinated with data from other sensors, including other Pave PAWS sites.
The original sites used two types of radars, the
L bandAN/FPS-50, with three fence antennas for initial detection, each 165 feet tall and 400 feet wide, and an AN/FPS-92 fully steerable tracking dish, 85 feet in diameter, installed in a large radome. One fence antenna covered a 40 degree sector of the horizon, for a total site coverage of 120 degrees. A prototype of BMEWS, located in Trinidad, began providing surveillanceand tracking of ballistic missiles by 1958, and went operational on February 4, 1959, to gather data on missiles fired at the Atlantic Missile Range, as well as satellites and meteors. The full BMEWS radar network became operational in the early 1960s. Each site had dual IBM 7094computers for signal processing and impact prediction.
Soviet Uniondeveloped a Fractional Orbital Bombardment System(FOBS) in part to counteract the network of sensors covering the northern hemisphere, including BMEWS, which was only able to point in a fixed direction. FOBS placed a warhead in low earth orbit, reducing the line-of-site ranges tremendously compared to the traditional "lofted" trajectories of a conventional ICBM. Additionally, the FOBS could be launched southward, overflying most of the globe and then approaching the US from the south, where it would be invisible to BMEWS. Submarine-launched ballistic missilesalso avoided detection by BMEWS, developing into a credible threat in the 1970s. The Defense Support Program(DSP) early warning satellites were developed in part to counter this threat, detecting the infrared"bloom" from the launch rockets no matter where they occurred.
On October 5, 1960, the
moonrise occurred directly in the path of the Thule detection radar, producing a strong signal return. While the computer system never generated an impact prediction, the large amount of data caused enough concern that the equipment was subsequently modified to reject moon returns based on their long (2 second) delay.
The Thule and Fylingdales sites were upgraded with
phased arrayradars in the 1990s. BMEWS 3, located in RAF Fylingdales, was upgraded by Raytheon/ Cossor AeroSpaceand Control Data Corporationat a cost of US $100M. The new antenna was a 3 faced phased array antenna providing 360 degrees of coverage. The embedded computer was a CDC-Cyber running JOVIAL.The Clear, Alaska site was upgraded in 2001 with a PAVE PAWSradar that was originally located at Eldorado Air Station, Texas. The phased array radars operate in the 420-450 MHz(UHF) frequencyrange.
Along with the PAVE PAWS radar sites at
Cape Cod Air Force Stationon Cape Cod, Massachusettscoord|41.7524|N|70.5386|W|, Beale Air Force Base, Californiacoord|39.1361|N|121.3506|W| and the PARCS radar at Cavalier AFS, North Dakotacoord|48.7246|N|97.8998|W|, the BMEWS sites provide continual ground-based missile warning for the United States and Canada, with satellite surveillance as a secondary role.
Nuclear weapons and the United States
Missile Defense Alarm System
Defense Support Program
*Specific US radar and locations
Cobra Dane, Eareckson Air Station, Alaska
Thule Air Base, Greenland
Clear Air Force Station, Alaska
RAF Fylingdales, United Kingdom
Cape Cod Air Force Station, Massachusetts
Beale Air Force Base, California
Cavalier Air Force Station, North Dakota
* Alternate Clear AFS, See [http://www.globalsecurity.org/space/facility/clear.htm Global's Clear AFS]
* [http://hdl.loc.gov/loc.pnp/hhh.ak0486 Historic American Engineering Record (Library of Congress)] (HAER AK-30-A) - Clear Air Force Station, Ballistic Missile Early Warning System Site II
* [http://www.bwcinet.com/thule/1intro.htm A detailed personal account of BMEWS]
* [http://www.globalsecurity.org/space/systems/bmews.htm Global's Space Systems information with pictures]
* [http://www.fas.org/spp/military/program/nssrm/initiatives/bmews.htm BMEWS Program overview from 1997]
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