<P> On March 18, 1959, the USAF told the BMEWS Project Office to proceed with an interim facility for the "AICBM control center" with an anti-ICBM C computer (e.g., for when the USAF Wizard and / or Army Nike Zeus ABMs became operational), and the basement of the 1954 ADC blockhouse was considered for the interim center . A "satellite prediction computer" could be added to the planned missile warning center if Cheyenne Mountain's "hardened COC slipped considerably beyond January 1962" (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". In late 1959, ARPA opened the 474L System Program Office, and BMEWS' "12th Missile Warning Squadron at Thule...began operating in January 1960 ." 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" (NORAD assumed "operational control of all space assets with the formation of" SPADATS in October 1960 .) 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 . </P> <P> Clear AFS construction began in August 1958 with 700 workers (completed July 1, 1961), and Thule Site J construction began by May 18, 1960, with radar pedestals complete by June 2 . Thule testing began on May 16, 1960, IOC was on September 30, and the initial operational radar transmission was in October 1960 (initially duplex vacuum tube IBM 709s occupied 2 floors). </P> <Dl> <Dt> False alarm </Dt> <Dd> On October 5, 1960, when Khrushchev was in New York, radar returns during moonrise at Thule produced a false alarm (on January 20, 1961, CINCNORAD approved 2 - second FPS - 50 frequency hopping to eliminate reception of echoes beyond artificial satellite orbits .) </Dd> </Dl> <Dd> On October 5, 1960, when Khrushchev was in New York, radar returns during moonrise at Thule produced a false alarm (on January 20, 1961, CINCNORAD approved 2 - second FPS - 50 frequency hopping to eliminate reception of echoes beyond artificial satellite orbits .) </Dd>

Bmews detects an unidentified object with the following parameters