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Semi-Automatic Ground Environment - Wikipedia, the free encyclopedia Page 1 of 11 Semi-Automatic Ground Environment From Wikipedia, the free encyclopedia The Semi-Automatic Ground Environment (SAGE) was a system of large computers and associated networking equipment that coordinated data from many Semi-Automatic Ground Environment radar sites and processed it to produce a single unified image of the airspace over a "Ground Environment of the CONUS wide area. SAGE directed and controlled the NORAD response to a Soviet air attack, Air Defense Systems" (1953)[1] operating in this role from the late 1950s into the 1980s. Its enormous computers and "Electronic Air Defense Environment" (1950)[2] huge displays remain a part of cold war lore, and a common prop in movies such as military C3 human-computer interface Dr. Strangelove and Colossus. Powering SAGE were the largest computers ever built, IBM's AN/FSQ-7. Each SAGE Direction Center (DC) contained two FSQ-7's for redundancy, filling two floors of a large cube-shaped concrete building. The upper two floors contained offices, operator stations, and a single two-story radar display visible to most of the DC's personnel. Information was fed to the DC's from a network of radar stations as well as readiness information from various defence sites. The computers, based on the raw radar data, developed "tracks" for the reported targets, and automatically calculated which defences were within range. Subsets of the data were then sent to the many operator consoles, where the operators used light guns to select targets onscreen for further information, select one of the available defences, and issue commands to attack. These commands would then be automatically sent to the defence site via teleprinter. Later The 4-story SAGE blockhouses with 3.5 acres (1.4 ha) additions to the system allowed SAGE's tracking data to be sent directly to CIM-10 [3] Bomarc missiles and some of the US Air Force's interceptor aircraft in-flight, directly of floor space "were hardened [for] overpressures of" [4]:264 updating their autopilots to maintain an intercept course without operator intervention. 5 psi (34 kPa). A shorter adjoining building (left) Each SAGE DC also forwarded data to a Combat Center (CC) for "supervision of the had generators below the 4 intake/exhaust structures on the roof.[5] several sectors within the division"[9] ("each combat center [had] the capability to coordinate defense for the whole nation").[10]:51 Connecting the various sites was an Countries United States, Canada enormous network of telephones, modems and teleprinters. Combat CC-01: NY (Hancock Field), Centers CC-02: WI (Truax Field), SAGE became operational in the late 1950s and early 1960s at a combined cost of CC-03: WA (McChord AFB)[6], billions of dollars. It was noted that the deployment cost more than the Manhattan CC-04: NY (Stewart AFB), Project, which it was, in a way, defending against. Throughout its development there CC-05: CA (Hamilton AFB)**, CC-06: MO (Richards-Gebaur AFB)*, were continual questions about its real ability to deal with large attacks, and several CC-xx: tests by Strategic Air Command bombers suggested the system was "leaky". ND Minot AFB* CC-yy: AZ Luke AFB* Nevertheless, SAGE was the backbone of NORADs air defence system into the 1980s, by which time the tube-based FSQ-7's were increasingly costly to maintain and Project Office USAF Air Material Command completely outdated. Today the same command and control task is carried out by Coordination Western Electric[7] Design microcomputers, based on the same basic underlying data. System Development Corporation[7] Equip. contract Burroughs Corporation [7] Operational 1958 June 26 — DC-01 Contents 1958 December 1 — DC-03 1959 (early) — CC-01 ◾ 1 Background 1966 April 1 — CC-05 ◾ 2 Development AN/FSQ-7 IBM Military Products Division [8] ◾ 3 Deployment *Combat Center not completed since AN/FSQ-8 ◾ 4 Description production was halted c. Nov 1958 when Super Combat The AN/FSQ-7 had 100 system Centers were planned[6]:26 with AN/FSQ-32s. ◾ 4.1 SAGE System consoles, including the OA-1008 **CC-05 at Hamilton AFB, CA utilized a 3-string Situation Display (SD) with a light ◾ 4.2 Radar stations AN/GSA-51 computer system and was active from Apr 1/66 to Dec 31/69. gun (at end of cable under plastic ◾ 4.3 Interceptors museum cover), cigarette lighter, and ash tray (left of the light gun). ◾ 5 Improvements ◾ 6 Replacement and disposition ◾ 7 Historiography ◾ 8 References ◾ 9 Further reading Background Computerized command and control for United States air defense was conceived in July 1945 during the Signal Corps' Project 414A contracted to Bell Laboratories[11]:207 after "employment of an American version of CDS", the British air defense C2 system, had been identified for air defense command and control on June 12.[12] The Priority Permanent System with the initial (priority) radar stations was http://en.wikipedia.org/wiki/Semi-Automatic_Ground_Environment 2-11-2014 Semi-Automatic Ground Environment - Wikipedia, the free encyclopedia Page 2 of 11 completed in 1952[4]:223 as a "manual air defense system"[7] (e.g., NORAD/ADC used a "Plexiglas plotting board" at the Ent command center.) The Permanent System radar stations included 3 subsequent phases of deployments and by June 30, 1957, had 119 "Fixed CONUS" radars, 29 "Gap-filler low altitude" radars, and 23 control centers".[13] At "the end of 1957, ADC operated 182 radar stations [and] 17 control centers … 32 [stations] had been added during the last half of the year as low-altitude, unmanned gap-filler radars. The total consisted of 47 gap-filler stations, 75 Permanent System radars, 39 semimobile radars, 19 Pinetree stations,…1 Lashup -era radar and a single Texas Tower".[4]:223 "On 31 December 1958, USAF ADC had 187 operational land-based radar stations" (74 were "P-sites", 29 "M-sites", 13 "SM-sites", & 68 "ZI Gap Fillers").[6] The December 1949 "Air Defense Systems Engineering Committee" led by Dr. George Valley had recommended computerized networking[14] for "radar stations guarding the northern air approaches to the United States"[15] (e.g., in Canada). After a January 1950 meeting, Valley and Jay Forrester proposed using the Whirlwind I (completed 1951) for air defense. On August 18, 1950, when the "1954 Interceptor" requirements were issued, the USAF "noted that manual techniques of aircraft warning and control would impose “intolerable” delays"[16]:484 (AMC published Electronic Air Defense Environment for 1954 in December .)[2] During February–August 1951 at the new Lincoln Laboratory, the USAF conducted Project Claude which concluded an improved air defense system was needed. The "Summer Study Group" of scientists in 1952 recommended "computerized air direction centers…to be ready by 1954."[17] IBM's "Project High" assisted under their October 1952 Whirlwind subcontract with Lincoln Laboratory,[18]:210 and a 1952 USAF Project Lincoln "fullscale study" of "a large scale integrated ground control system" resulted in the SAGE approval "first on a trial basis in 1953". [11]:128 The USAF had decided by April 10, 1953, to cancel the competing ADIS (based on CDS), and the University of Michigan’s Aeronautical Research Center withdrew in the spring.[19]:289 ARDC planned to "finalize a production contract for the Lincoln Transition System".[4]:201 Similarly, the July 22, 1953, report by the Bull Committee (NSC 159) identified completing the Mid-Canada Line as the top priority and "on a second-priority-basis: the Lincoln automated system"[20] (the decision to control Bomarc with the automated system was also in 1953.)[21] Development The 2 computers in each AN/FSQ-7 were based on the IBM 701,[22] used an improved version of the Whirlwind I magnetic core memory. On October 28, 1953, the Air Force Council recommended 1955 funding for "ADC to convert to the Lincoln automated system"[4]:193 ("redesignated the SAGE System in 1954").[4]:201 The "experimental SAGE subsector, located in Lexington, Mass., was completed in 1955… with a prototype AN/FSQ-7…known as XD-1"[9] (single computer system[23] in Building F).[19] In 1955, Air Force personnel began IBM training at the Kingston, New York, prototype facility,[5] and the "4620th Air Defense Wing (experimental SAGE) was established at Lincoln Laboratory" On May 3, 1956, General Partridge presented CINCNORAD’s Operational Concept for Control of Air Defense Weapons to the Armed Forces Policy Council,[11] and a June 1956 symposium presentation identified advanced programming methods of SAGE code.[27] For SAGE consulting Western Electric and Bell Telephone Laboratories formed the Air Defense Engineering Service (ADES),[28] which was contracted in January 1954.[19] IBM delivered the FSQ-7 computer's prototype in June 1956,[8] and Kingston's XD-2 with dual computers[23] guided a Cape Canaveral BOMARC to a successful aircraft intercept on August 7, 1958.[4]:197 Initially contracted to RCA, the AN/FSQ-7 production units were started by IBM in 1958 (32 DCs were planned[4]:207 for networking NORAD regions.)[29] IBM's production contract developed 56 SAGE computers for $½ billion (~$18 million per computer pair in each FSQ-7)[23]—cf. the $2 billion WWII Manhattan Project. General Operational Requirements (GOR) 79 and 97 were "the basic USAF documents guiding development and improvement of [the semi- automatic] ground environment.[30]:97 Prior to fielding the AN/FSQ-7 centrals, the USAF initially deployed "pre-SAGE semiautomatic intercept systems" (AN/GPA-37) to Air Defense Direction