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Ballistic Missile Early Warning System
BMEWS Central Computer and Display Facility in United States
Sketch of Clear Air Force Station BMEWS radars.[a]
TypeRadar network
Site history
Built1958–1961[4] (complete FOC was January 15, 1964)[5]
Built byRCA Defense Electronics Products[6]: 29 [b]
FateReplaced in 2001 by SSPARS

The RCA 474L Ballistic Missile Early Warning System (BMEWS, 474L System,[17] Project 474L) was a United States Air Force Cold War early warning radar, computer, and communications system,[18] for ballistic missile detection. The network of twelve radars,[12] which was constructed beginning in 1958 and became operational in 1961, was built to detect a mass ballistic missile attack launched on northern approaches [for] 15 to 25 minutes' warning time[19] also provided Project Space Track[20] satellite data (e.g., about one-quarter of SPADATS observations).[21]

It was replaced by the Solid State Phased Array Radar System in 2001.[22]


The Ballistic Missile Early Warning System (BMEWS) was a radar system built by the United States (with the cooperation of Canada and Denmark on whose territory some of the radars were sited) during the Cold War to give early warning of a Soviet intercontinental ballistic missile (ICBM) nuclear strike, to allow time for US bombers to get off the ground and land-based US ICBMs to be launched, to reduce the chances that a preemptive strike could destroy US strategic nuclear forces.

The shortest (great circle) route for a Soviet ICBM attack on North America is across the North Pole, so the BMEWS facilities were built in the Arctic at Clear Air Force Station in central Alaska, and Site J near Thule Air Force Base, Thule, Greenland. When it became clear in the 1950s that the Soviet Union was developing ICBMs, the US was already building an early-warning radar system in the Arctic, the DEW line, but it was designed to detect bombers and did not have the capability of tracking ICBMs.

The challenges of designing a system that could detect and track a massive strike of hundreds of ICBMs were formidable. The radar sites were located as far north in the Arctic as possible, to give maximum warning time of an attack. However, the time between when a Soviet missile would rise above the horizon and be detected and when it would reach its target in the US was only 10 to 25 minutes.


BMEWS consisted of two types of radars and various computer and reporting systems to support them. The first type of radar consisted of very large, fixed rectangular partial-parabolic reflectors with two primary feed points. They produced two fan-shaped microwave beams that allowed them to detect targets across a very wide horizontal front at two narrow vertical angles. These were used to provide wide-front coverage of missiles rising into their radar horizon, and by tracking them at two points as they climbed, enough information to determine their rough trajectory.

The second type of radar was used for fine tracking of selected targets, and consisted of a very large steerable parabolic reflector under a large radome. These radars provided high-resolution angular and ranging information that was fed to a computer for rapid calculation of the probable impact points of the missile warheads. The systems were upgraded several times over their lifetime, replacing the mechanically scanned systems with phased array radar that could perform both roles at the same time.

Three of the huge AN/FPS-50 radars, BMEWS Site 2, near Anderson, Alaska, in 1962.

BMEWS equipment included:[23]

To predict when parts might break down,[42] the contractor also installed RCA 501 computers[43] with 32k high-speed memory, 5-76KC 556 bpi 3/4" tape drives, & 200 track random access LFE drums.[citation needed] The initially-replaced portions of BMEWS included the Ent CC&DF by the Burroughs 425L Missile Warning System at the Cheyenne Mountain Complex[44] (FOC July 1, 1966.)[5] The original Missile Impact Predictors were replaced (IOC on August 31, 1984),[5] and BMEWS systems were entirely replaced by 2001 (e.g., radars were replaced with AN/FPS-120 SSPARS) after Satellite Early Warning Systems had been deployed (e.g., 1961 MIDAS, 1968 Project 949, and 1970 DSP satellites).

Classification of radar systems

Further information: Joint Electronics Type Designation System

Under the Joint Electronics Type Designation System (JETDS), all U.S. military radar and tracking systems are assigned a unique identifying alphanumeric designation. The letters “AN” (for Army-Navy) are placed ahead of a three-letter code.[45]

Thus, the AN/FPS-49 represents the 49th design of an Army-Navy “Fixed, Radar, Search” electronic device.[45][46]

Early tests

The Thule site J BMEWS station's detection arcs.[f]

On June 2, 1955, a General Electric AN/FPS-17 "XW-1" radar at Site IX[50] in Turkey that had been expedited was completed by the US in proximity to the ballistic missile launch test site at Kapustin Yar in the Soviet Union[12] for tracking Soviet rockets[49] and to demonstrate the feasibility of advanced Doppler processing, high-power system components, and computerized tracking needed for BMEWS [sic].[12]

The first missile tracked was on June 15, and the radar's parabolic reflector was replaced in 1958,[50] and its range was extended from 1000 to 2000 nautical miles[51] after the 1957 Gaither Commission identified that because of expected Soviet ICBM development, there would be little likelihood of SAC's bombers surviving since there was no way to detect an incoming attack until the first warhead landed.[52]

BMEWS' General Operational Requirement 156 was issued on November 7, 1957 (BMEWS was designed to go with the active portion of the WIZARD system) and on February 4, 1958; the USAF informed Air Defense Command (ADC) that BMEWS was an "all-out program" and the "system has been directed by the President, has the same national priority as the ballistic missile and satellite programs and is being placed on the Department of Defense master urgency list."[53] By July 1958 after NORAD manning began, ADC's 1954 blockhouse for the Ent AFB command center had inadequate floor space; and Ent's "requirement for a ballistic missile defense system display facility...brought renewed action...for a new command post"[7] (the JCS approved the nuclear bunker on February 11, 1959).

Planning and development

BMEWS tracking monitors in the Thule Tactical Operations Room, which were upgraded in 1987.[54][g]

On January 14, 1958, the US announced its decision to establish a Ballistic Missile Early Warning System[56] with Thule to be operational in 1959—total Thule/Clear costs in a May 1958 estimate were ~$800 million (an October 13, 1958, plan for both estimated completion in September 1960.)[57] The Lincoln Laboratory's radar at Millstone Hill, Massachusetts, was built and provided data to a 1958[58] for trajectory estimates, e.g., Cape Canaveral missiles, and an adjunct high-power UHF test facility employed the Millstone transmitter to stress-test the components that were candidates for the operational BMEWS.[12] (A twin of the Millstone Hill radar was dedicated at Saskatchewan's Prince Albert Radar Laboratory on June 6, 1959.)[12] A prototype AN/FPS-43 BMEWS radar[13] completed at Trinidad in 1958 went operational on February 4, 1959, the date of an Atlas II B firing from Cape Canaveral Launch Complex 11[59] (lunar reflection was tested January–June 1960).[60] On June 30, 1958, NORAD emphasized that the BMEWS could not be considered as a self-contained entity separate from the Nike Zeus, or vice versa.[61]

On March 18, 1959, the USAF told the BMEWS Project Office[where?] to proceed with an interim facility[62]: 93  for the "AICBM control center" with an anti-ICBM C3 computer[48]: 148  (e.g., for when the USAF Wizard[48]: 157  and/or Army Nike Zeus[63] ABMs became operational), and the basement of the 1954 ADC blockhouse was considered for the interim center.[48]: 158  A "satellite prediction computer" could be added to the planned missile warning center if Cheyenne Mountain's "hardened COC slipped considerably beyond January 1962"[62]: 93  (tunneling began in June 1961.) In early 1959 for use at Ent in September 1960, a BMEWS display facility with "austere and economical construction with minimum equipment" was planned in an "annex to the current COC building".[62] In late 1959, ARPA opened[where?] the 474L System Program Office,[17] and BMEWS' "12th Missile Warning Squadron at Thule...began operating in January 1960."[64] Following a Nike ABM intercept of a test missile, the planned Cheyenne Mountain mission was expanded in August 1960 to "a hardened center from which CINCNORAD would supervise and direct operations against space attack as well as air attack"[65] (NORAD assumed "operational control of all space assets with the formation of" SPADATS in October 1960.)[52] The 1st Aerospace Surveillance and Control Squadron (1st Aero) was activated at Ent AFB on February 14, 1961; and Ent's Federal Building was completed c. 1960-1.


4 AN/FPS-50 detection reflectors at Thule Site J.[h] The concrete foundation included a large refrigeration system to prevent the curing concrete's heat from melting the permafrost.

Clear AFS construction began in August 1958[42] with 700 workers[42] and was completed July 1, 1961,[42] and Thule Site J construction began by May 18, 1960,[67] with radar pedestals complete by June 2.[63] Thule testing began on May 16, 1960,[68] IOC was completed on September 30,[57] and the initial operational radar transmission was in October 1960[69] (initially duplex vacuum tube IBM 709s occupied two floors).[citation needed]

On October 5, 1960, when Khrushchev was in New York,[70] radar returns during moonrise at Thule[71] produced a false alarm. On January 20, 1961, CINCNORAD approved two-second FPS-50 frequency hoping to eliminate reception of echoes beyond artificial satellite orbits.[12] On November 24, 1961, an AT&T operator failure at their Black Forest microwave station northeast of Colorado Springs[72][unreliable source?] caused a BMEWS communications outage to Ent and Offutt – a B-52 near Thule confirmed the site still remained.[73]

Training for civilian technicians included a February 1961 RCA class in New Jersey for a Tracking Radar Automatic Monitoring class.[74] The "Clear Msl Early Warning Stn, Nenana, AK" was assigned to Hanscom Field, Massachusetts, by the JCA on April 1, 1961.[75] By May 16, 1961, Ent's "War Room at NORAD" had a glass map for plotting aircraft and had a "map [that] lights up" to show multiple impact ellipses and times "before the huge missile[s] would burst"[70] (separate from Ent's BMEWS CC&DF building, the 2 story blockhouse had a war room with, left of the main NORAD region display, a BMEWS display map and "threat summary display" with a count of incoming missiles.)[76][i] The Trinidad Test Site transferred from Rome AFB to Patrick AFB on July 1, 1961 (closed as "Trinidad Air Station" in 1971)[75] and the same month, the 1st Aero began using Ent's Space Detection and Tracking System (SPADATS) operation center in building P4's annex[77] (Cheyenne Mtn's Space Defense Center became fully operational in 1967.)[56] The BRCS undersea cable was cut "presumably by fishing trawlers" in September, October, and November 1961 (the BMEWS teletype and backup SSB substituted);[40] and in December 1961, Capt. Joseph P. Kaufman was charged "with giving [BMEWS] defense data to ... East German Communists."[78]

BMEWS surveillance wing

The 71st Surveillance Wing, Ballistic Missile Early Warning System, was activated on December 6, 1961, at Ent AFB (renamed 71st Missile Warning Wing on January 1, 1967, at McGuire AFB July 21, 1969 – April 30, 1971).[75] Syracuse's BMEWS Test Facility at GE's High-Power Radar Laboratory[79] became the responsibility of Rome Air Development Center on April 11, 1962[80] (Syracuse's Eagle Hill Test Annex closed in 1970)[75] and on July 31, 1962, NORAD recommended a tracking radar station at Cape Clear to close the BMEWS gap with Thule for low-angle missiles (vice those with the 15-65 degree angle for which BMEWS was designed.)[40] By mid-1962, BMEWS "quick fixes" for ECCM had been installed at Fylingdales Moor, Thule and Cape Clear AK[40] and by June 30, integration of BMEWS and SPADATS at Ent AFB was completed.[5] During the Cuban Missile Crisis, the Moorestown AN/FPS-49 radar on October 24 was "withdrawn from SPADATS and realigned to provide missile surveillance over Cuba."[40] 1962 "strikes and walkouts" delayed Fylingdales' planned completion from March until September 1963 and on November 7, the Pentagon BMEWS display subsytem installation was complete.[5] At the end of 1962, NORAD was "concerned over BMEWS' virtual inability to detect objects beyond a range of 1500 nautical miles."[40] The Moorestown FPS-49 completed a BMEWS "signature analysis program" on scale models by January 1963.[15]

Air Defense Command / Aerospace Defense Command

Fylingdales AN/FPS-49 radomes in 1986[j]

Operations transferred from civilian contractors (RCA Government Services)[6]: 29  to ADC on January 5, 1962[69] (renamed Aerospace Defense Command in 1968.) Fylingdales became operational on September 17, 1963,[84][69] and Site III transferred to RAF Fighter Command on January 15, 1964. [85] Remaining BMEWS development responsibilities transferred to the "Space Track SPO (496L)" when the BMEWS SPO closed on February 14, 1964[5]—e.g., the AN/FPS-92 with "66-inch panels"[86] was added to Clear in 1966[87] (last of the 5 tracking radars),[88] and in 1967, BMEWS modification testing was complete on May 15, when the system cost totaled $1.259 billion,[5] equivalent to $8.78 billion in 2023.[89] In 1968, Ent's 9th Division HQ had a Spacetrack/BMEWS Maintenance Section.[90]

In 1975, SECDEF told Congress that Clear would be closed when Cobra Dane and the Beale AFB PAVE PAWS became operational.[91] By 1976, BMEWS included IBM 7094, CDC 6000, and Honeywell 800 computers.[92]

USAF Space Command

On October 1, 1979, Thule and Clear transferred to Strategic Air Command when ADCOM was broken up[93] then to Space Command in 1982. By 1981 Cheyenne Mountain had been averaging 6,700 messages per hour[94] compiled via sensor inputs from BMEWS, the JSS, the 416N SLBM "Detection and Warning System, COBRA DANE, and PARCS as well as SEWS and PAVE PAWS" for transmission to the NCA.[95] To replace AN/FSQ-28 predictors, a late 1970s plan for processing returns from MIRVs[96] installed in new Missile Impact Predictor computers was complete by September 1984.[5][54]


The BMEWS was replaced by the Solid State Phased Array Radar System in 2001.[22]

See also


  1. ^ Replaced by a Solid State Phased Array Radar System[1] constructed April 16, 1998 – February 1, 2001.[2][3]
  2. ^ RCA was contracted in January 1958[7] and employed 485 large companies and 2415 smaller firms spread over 29 states[8] ($474,831,000 contract in February 1960)[9]
  3. ^ a b Air Defense Command radar stations (cf. ADC general surveillance stations)
  4. ^ site for FPS-50 prototype[12] (AN/FPS-43)[13]
  5. ^ site for 1959–76[16][unreliable source?] FPS-49 prototype[13] and test/training[6]
  6. ^ The Thule site J BMEWS station's detection arcs of 200°[47] were a missile warning "fence" created by 4 radars' separate arcs: each AN/FPS-50 created 2 arcs (shown) centered at 3.5° and 7° elevation[13] (exaggerated in illustration.) Each arc was created by a smaller radar beam ~1° wide x 3.5° high at a "horizontal sweep enough that a missile or satellite cannot pass through...undetected".[13] Concerns in 1962 of "ERBM's (Extended Range Ballistic Missiles)" were that missile speeds after burnout would be higher than the initially-deployed Soviet ICBMs[48] and prevent the sweeping "Lower Fan" and then the "Upper Fan" (with "revisit time of 2 sec")[49] from detecting the missiles. A missile within the lower arc (~1.75-5.25° elevation) would be detected at a "Lower Fan Q Point" (black dot) and then by the upper fan (black dot with jagged outline), which allowed the impact area to be estimated from "where the object crossed the two fans and the elapsed time interval between fan crossings"[13] (displays showed the uncertain impact point as an elliptical area.) The free flight range of the missile outside the atmosphere (burnout to reentry) depends on the flight path angle and on the missile's parametric value of Q calculated from altitude and speed—additional ballistic range within the atmosphere to an estimated burst altitude was determined from computerized look-up tables in the Missile Impact Predictor.[13]
  7. ^ (renamed "Missile Warning Operations Center"[55])
  8. ^ replaced by an AN/FPS-120 with "two-faced...phased array 2QFY87."[66]
  9. ^ The p. 4 command post photo caption does not identify if it is in the Ent blockhouse (1954–1963) or in the Chidlaw Building, where war room operations moved to the NORAD/CONAD Combined Operations Center in 1963.
  10. ^ 2 of 3 radars were "constantly swinging back and forth in preset arcs to the east and north, looking 4,800 kilometres into space, from just above the horizon to nearly straight overhead".[81] Fylingdales radars were replaced by Raytheon/Cossor AeroSpace and Control Data Corporation, at a cost of US $100M (3-faced phased array antenna and embedded CDC-Cyber computer)[citation needed] and later changed to an Upgraded Early Warning Radar by Boeing Integrated Defense Systems[82] with 3 faces built August 1989-October 1992.[83]


  1. ^ "Raytheon wins Air Force Contract for Radar and Communications Sites (Press Release)". Raytheon via September 7, 1994.
  2. ^ "AN/FPS-120 Solid State Phased-Array System [SSPARS]: Clear Radar Upgrade". Retrieved March 8, 2014.
  3. ^ "Clear AFS, AK". Retrieved March 5, 2014.
  4. ^ "HAER AK-30-A - Clear Air Force Station, Ballistic Missile Early Warning System Site II". Historic American Engineering Record. 2003.
  5. ^ a b c d e f g h i Del Papa, Dr. E. Michael; Warner, Mary P (October 1987). A Historical Chronology of the Electronic Systems Division 1947–1986 (PDF) (Report). Archived (PDF) from the original on December 24, 2013. Retrieved March 8, 2014. 7 November [1984] Installation of [SSPARS] radar hardware at Site I, Thule, Greenland, for the Ballistic Missile Early Warning System (BMEWS) was begun.
  6. ^ a b c d e Shore, Bruce (Spring 1963). "the fourth state of matter". Electronics Age. RCA. Several hundred RCA management, technical, and engineering personnel run the 80 control stations that make up White Alice, the country's largest over-the-horizon communications system. The stations, mostly on mountaintops, employ two types of antenna – one a 30-foot, disc-shaped structure and the other a 100-ton scoop-shaped unit 60 feet tall. The antennas relay signals from one to the other, sometimes over distances up to 170 miles. … In 1952, Mr. Heller led a group of RCA field engineers to a minor military installation at Cape Canaveral. From this simple beginning, the RCA Service Company became a subcontractor to Pan American for the planning, systems engineering, operation, and maintenance of the vast complex instrumentation systems that constitute the Atlantic Missile Range.
  7. ^ a b c Preface by Buss, L. H. (Director) (October 1, 1958). North American Air Defense Command Historical Summary: January–June 1958 (Report). Directorate of Command History: Office of Information Services. NORAD looked at the Zl portion of the BMEWS not only as an integral portion of the system, but as the heart of the entire ballistic missile defense system.
  8. ^ Engstrom, E.W. (February 1984). "The years 1958-1962" (PDF). 100 Years With IEEE In The Delaware Valley, Part 1. Philadelphia Section of IEEE. p. 16.
  9. ^ "Big Missile-Warning System Outlay". The Age. Melbourne. Australian Associated Press. February 16, 1960.
  10. ^ "Remembering Our Heritage 25 June - 1 July" (PDF). Office of History, Elmendorf AFB via Retrieved November 5, 2016. ...facilities to accommodate the radar came to $62 million. More than 1,100 workers worked on the project. It involved excavating 185,000 cubic yards of dirt and gravel and the pouring of 65,000 yards of concrete. Materials totaled 4,000 tons of structural steel, 2,600 tons of reinforcing steel and 900,000 square feet of fabricated panels.
  11. ^ "FYLINGDALES: Home of the Number One BMEWS Detachment" (image copy at Q Point. 9th Aerospace Defense Division. August 1967. Retrieved March 5, 2014.
  12. ^ a b c d e f g h Stone & Banner. Radars for the Detection and Tracking of Ballistic Missiles, Satellites, and Planets (PDF) (Report). Archived from the original (PDF) on May 12, 2013. Retrieved March 5, 2014. The Millstone radar served as a development model for RCA's AN/FPS-49, AN/FPS-49A, and AN/FPS-92 radars, all of which were used in the BMEWS. Millstone was used to develop a fundamental understanding of several important environmental challenges facing the BMEWS. These challenges included the measurement of UHF propagation effects in the ionosphere, the impact of refraction close to the horizon, the effect of Faraday rotation on polarization, and the impact of backscatter from meteors and the aurora on the detection performance of the radar and its false-alarm rate [15–17]. In the early 1960s, the Millstone radar was converted from a UHF to an L-band system. The Air Force in the 1960s sponsored the development of Haystack, a versatile facility in Tyngsboro, Massachusetts, that supports radar- and radio-astronomy research and the national need for deep-space surveillance.
  13. ^ a b c d e f g h i Bate; Mueller & White (1971) [origyear tbd]. Fundamentals of Astronautics (Google books). Courier Corporation. ISBN 9780486600611. Retrieved March 5, 2014. fan-shaped beams, about 1° in width and 3½° in elevation… The horizontal sweep rate is fast enough that a missile or satellite cannot pass through the fans undetected.
  14. ^ "USS Rancocas: The Cornfield Cruiser". Retrieved March 10, 2014. Originally owned by the Air Force, the building was constructed in the 1950s. For years it was an Air Force-operated radar site, operating a ballistic missile early warning system. The warehouse-like gray building was topped by a radome...
  15. ^ a b Scale Model Radar Cross Section Data (PDF) (Report). BLDG 116-20, RCA, Moorestown NJ: Detachment 3, 9th...Division. January 10, 1963. Archived from the original (PDF) on March 11, 2014. Retrieved March 9, 2014. eventual transfer to a Spacetrack Analysis Center at Colorado Springs.((cite report)): CS1 maint: location (link)
  16. ^ Flack, John S. Jr. "Moorestowns Giant Golf Ball" (personal anecdote w/ photos). Personal web page on Retrieved March 10, 2014. It was taken out of service in December, 1974 and dismantled in early 1976. After this, RCA built a replica of a US Navy cruiser deckhouse atop the building that the golf ball sat on for testing its Aegis Combat System and for training Navy personnel. The Aegis facility is still located here, operated jointly by Lockheed Martin (which now operates the radar plant) and the Navy.
  17. ^ a b "Ballistic Missile Early Warning System (BMEWS): AN/FPS-50 Detection Radar AN/FPS-92 Tracking Radar". Retrieved March 5, 2014.
  18. ^ Edwards, Paul N. (1997). The Closed World: Computers and the Politics of Discourse in Cold War America (Google Books). MIT Press. p. 107. ISBN 9780262550284. SAGE—Air Force project 416L—became the pattern for at least twenty-five other major military command-control systems… These were the so-called "Big L" systems and included 425L, the NORAD system; 438L, the Air Force Intelligence Data Handling System; and 474L, the Ballistic Missile Early Warning System (BMEWS). … Project 465L, the SAC Control System (SACCS)
  19. ^ McNamara, Robert (November 3, 1961). Report to the US Senate Preparedness Investigating Subcommittee on Warning and Detection systems (PDF) (Report). National Archives via p. 5.
  20. ^ "Archived copy" (PDF). Archived from the original (PDF) on March 11, 2014. Retrieved March 11, 2014.((cite web)): CS1 maint: archived copy as title (link)
  21. ^ Peebles, Curtis (June 1997). High Frontier: The U.S. Air Force and the Military Space Program. DIANE. p. 39. ISBN 9780788148002.
  22. ^ a b Chapman, Bert (2008). Space Warfare and Defense: A Historical Encyclopedia and Research Guide (Google books). Bloomsbury Academic. ISBN 9781598840063. Retrieved March 13, 2014. BMEWS was replaced by the Solid State Phased Array Radar System (SSPARS) in 2001. ... CINCAD (Command in Chief, Aerospace Defense Command)
  23. ^ a b "Annual Report of the Secretary of Defense, The Armed Forces, pp. 14-15 ("Continental Air Defense" section)" ( excerpt). Department of Defense Annual Report (Report). 1960. Retrieved March 6, 2014. The imminent shift in the air threat to our security from aircraft alone to ballistic missiles and aircraft led to [require] a reduction in the programs for the BOMARC missile and the hardened "supercombat" centers for the Semi-Automatic Ground Environment (SAGE) system, and an acceleration in the modernization of the fighter interceptor forces and in the construction of the Ballistic Missile Early Warning System (BMEWS) [with] three widely dispersed, long-range radar stations, a central computer and display facility in the United States, and a communications network to link the separate elements.
  24. ^ Fay, Elton C. (May 18, 1960). "Radar Net Nearing Completion". Register-Guard. Eugene, Oregon. AP.
  25. ^ "FPS-50".
  26. ^ "AN/FPS-49, 49A". Retrieved March 5, 2014. The prototype unit operated at Moorestown, New Jersey
  27. ^ "Thule's Electronic Sentinel" (Google news archive). The Milwaukee Journal. January 4, 1961. Retrieved March 9, 2014.
  28. ^ "FPS-92". Retrieved June 25, 2023.
  29. ^ "MONITORING SET, RADAR - continued - TM-11-487C-10192". Archived from the original on March 11, 2014. Retrieved March 11, 2014.
  30. ^ "Cold War Comms Group forum". Archived from the original on March 11, 2014.
  31. ^ title tbd (PDF) (Report). Retrieved March 7, 2014. Missile Impact Predictor Set AN/FSQ-28 accepts output of Radar Set AN/FPS-19 or AN/FPS-19A and Radar Set AN/FPS-50(V) to determine the trajectory of space objects and predicts the point of impact. Furnishes designation data to tracking Radar for enhancing target data accuracy. The AN/FSQ-28 is a duplex, general purpose computer (IBM-709-TX with real-time terminal and control equipment added).
  32. ^ "Archived copy". Archived from the original on March 11, 2014. Retrieved March 11, 2014.((cite web)): CS1 maint: archived copy as title (link) the USA and UK agreed to be separately responsible for their own rearward data handling systems.’ [46] The UK systems were to meet Air Staff Requirement 2208 and called for ‘display of processed IRBM data at the Air Defence Operations Centre (ADOC), the Bomber Command Operations Centre (BCOC), the Air Ministry Operations Centre and, for standby purposes, at the Air Defence Main Control Centre and Headquarters No. 1 Group. The processed data will also be passed to NORAD over the USA rearward data handling system and this system
  33. ^ a b Gandy, A. (November 30, 2012). The Early Computer Industry: Limitations of Scale and Scope. Springer. p. 48. ISBN 9780230389113.
  34. ^ Moora, Robert L (Autumn 1960). "BMEWS Takes Shape…On Schedule: Greenland radar site begins early warning operations…" (PDF). Electronic Age. Retrieved March 6, 2014. a "data takeoff" computer translates the visual image into digital form, calculating distance, range, angle of flight, speed and direction. In split seconds, this data is on its way to a high-speed "missile impact predictor" computer. … prime system contractor is the Radio Corporation of America, with headquarters at the Missile and Surface Radar Division, Moorestown… Principal subcontractors to RCA include General Electric Company…
  35. ^ "ABMWSP Summary - 23 Apr 1960". World War III wargame alternative reality website. Progress is satisfactory on the establishment of rearward communications from the forward sites to the Zone of the Interior display facilities at Colorado Springs, Colorado. On 1 December, through communication was established between the switchboard at Thule and the BMEWS Project Office in New York City. This tie line, together with a similar one between Thule and Westover Air Force Base, Massachusetts, represents the first use to be made of the submarine cable completed this last summer between Thule and Cape Dyer.
  36. ^ Olsson, Tom (October 31, 1969). Report of the Economic Committee on Domestic Satellites (PDF) (Report). US Office of Telecommunications Management via
  37. ^ Mitchell, Walt. "Memories of Troposcatter at Resolution Island". Archived from the original on March 11, 2014. Retrieved March 9, 2014. he BMEWS Rearward link came from Thule to Dye to ResX1 to ResX on Resolution and then on to Goose Bay. I suspect that was the link maintained by Canadian Marconi under contract in the 1961 to 1974 period.
  38. ^ "DEWDROP Troposheric Scatter AM Communications Link between Thule BMEWS and Cape Dyer". Archived from the original on March 11, 2014. Retrieved March 11, 2014.
  39. ^ Bubb, John. "Tropospheric Scatter Communications Site Saglek Labrador Canada Circa 1969/70". Personal Webpage at Archived from the original on March 11, 2014. Retrieved March 11, 2014.
  40. ^ a b c d e f "1962 NORAD/CONAD Historical Summary, July-December" (PDF). Retrieved June 25, 2023.
  41. ^ SAC Command Post, Reel 2. National Archives Motion Pictures Unit, Record Group 342 via Retrieved March 10, 2014.
  42. ^ a b c d "Watchful eye of BMEWS turns toward Soviets" (Google news archive). Ellensburg Daily Record. June 18, 1961. Retrieved March 9, 2014.
  43. ^ "RCA501". Archived from the original on July 2, 2012.
  44. ^ "NORAD's Information Processing Improvement Program: Will It Enhance Mission Capability?" (Report to Congress). Comptroller General. September 21, 1978. Retrieved January 24, 2013. The 496L Spacetrack system uses a Philco 212 computer as its primary processor. … The off-line utility processors are two Philco 1000 computers which can also serve as backup processors for the 496L system and the Automatic Digital Relay Switch, if necessary. … The NCS segment will replace the Burroughs 425L Command and Control system including the Univac 1218s, the 425L Back-up system, the Command Center Processing system, and the Display Information Processor.
  45. ^ a b Avionics Department (2013). "Missile and Electronic Equipment Designations". Electronic Warfare and Radar Systems Engineering Handbook (PDF) (4 ed.). Point Mugu, California: Naval Air Warfare Center Weapons Division. p. 2-8.1.
  46. ^ Winkler, David F. (1997). "Radar Systems Classification Methods". Searching the Skies: The Legacy of the United States Cold War Defense Radar Program (PDF). Langley AFB, Virginia: United States Air Force Headquarters Air Combat Command. p. 73. LCCN 97020912.
  47. ^ Hanley, Charles J (August 17, 1987). "Soviets, Eskimos protest Thule radar" (Google news archive). Morning Star. Wilmington, North Carolina. Associated Press. Retrieved March 9, 2014. The radar, a Phased Array Warning System…can "see" 3,200 miles, 200 miles farther than the old system, and has a 240-degree arc…40 degrees more than the old.
  48. ^ a b c d Preface by Buss, L. H. (Director) (April 14, 1959). North American Air Defense Command and Continental Air Defense Command Historical Summary: July–December 1958 (Report). Directorate of Command History: Office of Information Services.
  49. ^ a b Skolnik, Merrill. "Oral-History" (audio transcript). IEEE Global History Network. Retrieved March 10, 2014.
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  53. ^ USAF memo to Air Defense Command cited in 1958 NORAD/CONAD Historical Summary, Jan-Jun
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  71. ^ Sampson, Curt (January 25, 2010). "The Moon as a Soviet Missile Attack". Retrieved March 5, 2014.
  72. ^ "AT&T caused NORAD blackout". EVER WONDER?. Colorado Springs Gazette. August 26, 2011. Retrieved March 10, 2014. an engineer we'll call "Q" didn't follow instructions "for routining a TD2 transmitter and receiver." He enclosed diagrams showing what went wrong. There was no "500A termination on the Channel Dropping Network when he was running the Radio Frequency (RF) Sweep Generator to adjust the equipment." That generator leaked RF into the Channel Separating Filter "interfering with all the other transmitters in the Black Forest Microwave Station, causing a complete failure of all channels going to Ent. SAC scrambled all aircraft. Later SAC billed AT&T for all the fuel used."
  73. ^ Philips, Alan F. "20 Mishaps That Might Have Started Accidental Nuclear War". Retrieved March 5, 2014.
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  76. ^ "NORAD Center Located At Colorado Springs Site" (Google news archive). The Othello Outlook. November 26, 1964. p. 3. Retrieved March 9, 2014. COMMAND POST – The main battle staff position in the Combat Operations Center (COC)...fronts a display area which allows observers to see the positions of airborne objects thousands of miles away.
  77. ^ [full citation needed]1961–1969 Historical reports from the Squadron on file at the Air Force Historical Research Agency, Maxwell AFB AL, AFHRA Microfilm reel KO363
  78. ^ "Captain Faces Secrets Count". The Deseret News. HTNS. December 22, 1961. p. A3.
  79. ^ "Of current interest: Surveillance radar subsystem for Air Force's BMEWS, Site 1". Electrical Engineering. 79 (5): 430–431. 1960. doi:10.1109/EE.1960.6432626.
  80. ^ Forty Years of Research and Development at Griffis Air Force Base: June 1951-June 1991 (PDF) (Report). Rome Laboratory. Archived from the original on April 8, 2013. Retrieved March 10, 2014.
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  84. ^ "Early Warning System has Important Role in NORAD". The Othello Outlook. Othello, Washington. November 26, 1964. p. 6.
  85. ^ Wilson, B.C.F. (January 1, 1983). A History - Royal Air Force Fylingdales. Royal Air Force Flyingdales (January 1, 1983). ISBN 0950852104. [plaque in the Tactical Operations Room] This plaque commemorates the commissioning of Royal Air Force Fylingdales as Site III of the Ballistic Missile Early Warning System on 17 September 1963. This site is a joint enterprise of the United States of America and Great Britain for the protection of both the North American Continent and the United Kingdom.
  86. ^ Radome is maze of wires, girders. March 29, 1962. p. 17. ((cite book)): |newspaper= ignored (help)
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  88. ^ "Electronic Eye Watches For Sneak Missile Attack" (Google news archive). Herald-Journal. July 8, 1966. Retrieved March 9, 2014. rotating 84-foot parabolic radar dish antenna…weighing 185 tons, can detect and track a 16-inch piece of wire 1-32nd of an inch in diameter, at a distance of 2,500 miles… The electronic dishes, each costing $19 million…
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  91. ^ Schlesinger, James R. (February 5, 1975). Report of the Secretary of Defense to the Congress on the FY 1976 and Transition Budgets... (PDF) (Report). Archived from the original (PDF) on November 27, 2011.
  92. ^ "Electronic Technicians BMEWS" (PDF). p. 27. Archived from the original (job advertisement) on March 11, 2014. Retrieved March 6, 2014. FELEC Services…a subsidiary of Federal Electric…newly awarded contract at Thule…IBM 360-7090 and 7094; CDC 6000; Honeywell 800
  93. ^ compiled by Johnson, Mildred W (December 31, 1980) [Feb 1973 original by Cornett, Lloyd H. Jr]. A Handbook of Aerospace Defense Organization 1946–1980 (PDF). Peterson AFB: Office of History, Aerospace Defense Center. Archived from the original (PDF) on November 23, 2006. Retrieved March 26, 2012.
  94. ^ Failures of the North American Aerospace Defense Command's (NORAD) attack warning system (minutes of "hearings before a subcommittee of the Committee on Government Operations, House of Representatives, Ninety-seventh Congress; May 19 and 20, 1981") (Report). United States Government Printing Office. Retrieved January 23, 2013. at Norad is the establishment of a Systems Integration Office
  95. ^ Modernization of the WWMCCS Information System (WIS) (ADA095409) (Report). United States House Committee on Armed Services. January 19, 1981. Archived (PDF) from the original on December 24, 2013. Retrieved August 29, 2012.
  96. ^ Aldridge, Robert C. (1983). First Strike!: The Pentagon's Strategy for Nuclear War. South End Press. p. 197. ISBN 9780896081543.