Experimental SAGE Subsector
{{For|the subsequent computer system with different peripherals and IBM's Kingston XD-2 computer; and for the late 1960s system for discerning incoming ICBM warheads|AN/FSQ-7|CDC 6600{{!}}Lexington Discrimination System}}
The Experimental Semi-Automatic Ground Environment (SAGE) Sector (ESS, Experimental SAGE Subsector{{cite web|url=http://www.dtic.mil/cgi-bin/GetTRDoc?AD=AD0419183 |archive-url=https://web.archive.org/web/20150103070657/http://www.dtic.mil/cgi-bin/GetTRDoc?AD=AD0419183 |url-status=dead |archive-date=January 3, 2015 |title=Data Reliability of Three Bell A1 Magnetic Tape Recording Systems |publisher=Defense Technical Information Center |access-date=2015-05-18}} until planned Sectors/Subsectors were renamed NORAD Regions, Divisions, and Sectors){{Cite NORAD Historical Summary |year=1958 |period=January–June}} was a prototype Cold War Air Defense Sector for developing the Semi Automatic Ground Environment. The Lincoln Laboratory control center in a new building{{Cite book |last1=Wildes |first1=Karl L. |last2=Lindgren |first2=Nilo A. |orig-year=1985 |year=1986 |title=A Century of Electrical Engineering and Computer Science at MIT, 1882-1982 |publisher=MIT Press |url=https://archive.org/details/centuryofelectri0000wild |url-access=registration |page=[https://archive.org/details/centuryofelectri0000wild/page/299 299] |access-date=2014-08-07 |quote=The first experimental subsector was a square approximately 400 nautical miles on a side and centered at Sourh Truro, Massachusetts. A new building was constructed at Lincoln Laboratory to house the XD-1 computer [which] was received from IBM in January|isbn=9780262231190 }} was at Lexington, Massachusetts.
ESS Computer System
The network's Direction Center was completed in a new 1954 building{{r|WildesNilo}} (Building F,{{r|RedmondSmith}} {{Coord|42|27|37|N|071|16|04|W|notes={{cite web|url=http://www.radomes.org/museum/showsite.php?site=Lincoln+Lab+ESS,+MA|title=Display site|publisher=radomes.org|access-date=2015-05-18}}}}) with prototype peripherals and a single IBM XD-1 computer,{{cite web |title=Introduction |url=http://ed-thelen.org/SageIntro.html |publisher=Ed-Thelen.org}} (p. 7) a successor to Lincoln Lab's Whirlwind I computer (WWI).{{cite web |year=1998 |title=Vigilance and Vacuum Tubes: The SAGE System 1956-63 |url=http://ed-thelen.org/Sage-Talk.html |format=SAGE Talk Transcript |publisher=Ed-Thelen.org |access-date=2013-02-16 |quote=the Whirlwind computer, which was a digital version of the ASCA, was about five million dollars, in {{sic|1950’s}} dollars … For the 1949 fiscal year, MIT requested 1.5 million dollars for the Whirlwind project. … one [SAGE computer] was at Lincoln Lab, …the XD-1, and the other one was at Kingston, the XD-2. So we used both those sites for development. … The XD-1 was a simplex system…not duplex … the original vacuum-tube computers—the last one was finally taken down in 1983, still operating. … IBM got…about 500 million dollars…to build the 56 computers.}} In 1955, Air Force personnel began IBM training at the Kingston, New York, prototype facility,{{Cite journal |last=Edwards |first=Benj |date=January 24, 2013 |title=…World's First Computer Art… |url=https://www.theatlantic.com/technology/archive/2013/01/the-never-before-told-story-of-the-worlds-first-computer-art-its-a-sexy-dame/267439/ |journal=The Atlantic |access-date=2013-02-16 }} and the "4620th Air Defense Wing (experimental SAGE) was established{{When|date=August 2014}} at Lincoln Laboratory"—its "primary mission was computer programming".{{Cite report |last=Schaffel |first=Kenneth |year=1991 |title=Emerging Shield: The Air Force and the Evolution of Continental Air Defense 1945-1960 |url=https://archive.org/details/TheEmergingShield/page/283 |format=45MB pdf |work=General Histories |publisher=Office of Air Force History |isbn=0-912799-60-9 |page=[https://archive.org/details/TheEmergingShield/page/283 283 (pdf)] |access-date=2011-09-26 }}
ESS had a capacity of 48 tracks and used a pre-SAGE ground environment in a "prototype intercept monitor room [at] MIT's Barta building" with "track situation displays, which geographically showed Air Defense Identification Zone lines and antiaircraft circles [and] each console also had a 5-inch CRT for digital information display. Audible alert signals were used, with a different signal for each symbol on a situation display."{{r|CCS-ESS}}
Radar stations
Initial service test models of the Burroughs AN/FST-2 Coordinate Data Transmitting Set were placed with radars at South Truro and West Bath, Maine; followed by Texas Tower#2 (TT2) in the Atlantic Ocean, which provided a "triangular pattern with overlap" radar coverage https://dome.mit.edu/bitstream/handle/1721.3/40551/MC665_r15_M-3832.pdf?sequence=1 |quote=ADES JPO initial Burroughs service test models of FST-2…would be placed at South Truro and Bath, respectively, in order to have an operational experimental subsector containing two heavy radars by 1 April 1956 [and] the third FST-2 on Texas Tower #2 [for] a triangular pattern providing overlap. XD-1 display system External Environment of XD-1…XD-1 Direction Center (TT2 later had a connection from the XD-1 via the GE G/A Data Link Output Subsystem through North Truro Air Force Station.){{Cite report |format=synopsis (MC665_r14_6M-3797.pdf) |title=Biweekly Report For Period Ending 23 March 1956 |url=http://dome.mit.edu/bitstream/handle/1721.3/46009/MC665_r14_6M-4263.pdf?sequence=1 |publisher=Lincoln Laboratory Division 6 |number=Memorandum 6M-4263 |access-date=2014-08-02}} By August 1955, 13 radar stations were networked by the subsector,{{r|CCS-ESS}} e.g.:
- Chatham{{cite web|url=http://www.radomes.org/museum/showsite.php?site=Chatham+ESS,+MA |title=Display site|publisher=radomes.org|access-date=2015-05-18}}
- Clinton, Massachusetts with gap-filler radar{{cite web|url=http://67.69.104.76:84/Pinetreeline/misc/equip/misc12aa.html|title=Pinetree Line Miscellaneous - Radar Equipment|publisher=67.69.104.76:84|access-date=2015-05-18|archive-url=https://web.archive.org/web/20140815204636/http://67.69.104.76:84/Pinetreeline/misc/equip/misc12aa.html|archive-date=2014-08-15|url-status=dead}}
- Great Boars Head{{cite web|url=http://www.northamericanforts.com/East/New_Hampshire/Towers/Great_Boars_Head.html |title=Download Mozilla Firefox Optimized for Yahoo|publisher=northamericanforts.com|access-date=2015-05-18}}
- Halibut Point{{cite web|url=http://www.northamericanforts.com/East/New_Hampshire/Towers/Halibut_Point.html |title=Download Mozilla Firefox Optimized for Yahoo|publisher=northamericanforts.com|access-date=2015-05-18}}
- Killingly, Connecticut ({{Coord| 41.865734|-71.820958}}).with gap-filler radar [https://archive.today/20140806141358/http://virtualglobetrotting.com/map/abandoned-radar-site-13.kml] (see also [http://www.radomes.org/museum/showsite.php?site=MITRE+Test+Site,+West+Bath,+ME Radomes.org listing for West Bath]
- Rockport Air Force Station
- Scituate, Massachusetts{{cite web|url=http://www.radomes.org/museum/recent/ScituateESSMA.html |title=Recent photos of Scituate (MA) Experimental SAGE Subsector (ESS) Radar Site|publisher=radomes.org|access-date=2015-05-18}}
- South Truro{{cite web|url=http://www.radomes.org/museum/equip/MITRESouthTruroMA.html|title=MITRE Radar Test Sites South Truro, Cape Cod, MA; Jug Handle Hill, West Bath, ME; Montauk LI, NY|publisher=radomes.org|access-date=2015-05-18}}
- West Bath, Maine ({{Coord|43|54|7|N|69|50|43|W}}) with AN/FPS-31{{cite web|url=http://wikimapia.org/17058280/West-Bath-MITRE-AN-FPS-31-Radar-Test-Site |title=West Bath MITRE AN/FPS-31 Radar Test Site|publisher=wikimapia.org|access-date=2015-05-18}} on Jug Handle Hill:{{cite web|url=http://www.ll.mit.edu/about/History/earlywarningradars3.html|title=MIT Lincoln Laboratory: History: SAGE Radars (part 3)|publisher=ll.mit.edu|access-date=2015-05-18|archive-url=https://web.archive.org/web/20130312152819/http://www.ll.mit.edu/about/History/earlywarningradars3.html|archive-date=2013-03-12|url-status=dead}} ("Lincoln Laboratories experimental radar station"){{cite web|url=https://newspaperarchive.com/us/maine/bath/bath-independent/1956/05-10/page-5 |title=Bath Independent, May 10, 1956|date=10 May 1956|publisher=newspaperarchive.com|access-date=2015-05-18}}
Required by 21 November 1955 were 44 consoles: 38 for the operations floor, 3 on the computer floor for display maintenance, and 3 near the maintenance console (program checkout).{{cite web|url=http://dome.mit.edu/bitstream/handle/1721.3/40520/MC665_r15_M-3857.pdf?sequence=1|publisher=dome.mit.edu|access-date=2015-05-18}} WWI was connected to the Experimental SAGE Subsector to verify crosstelling (collateral communication) with the ESS DC, and WWI was also used for a Ground-to-Air (G/A) experiment using a transmitter of the GE G/A Data Link Output Subsystem on Prospect Hill, Waltham, MA sending data to simulated airborne equipment at Lexington.{{r|M-4263}} Transmissions from the WWI SAGE Evaluation (WISE) computer system{{r|WildesNilo}} to XD-1 and back were without error by December 1955{{r|WildesNilo}} when operational software specifications were frozen.{{Cite book |last=Johnson |first=Stephen B. |title=The United States Air Force and the culture of innovation 1945-1965 |url=https://books.google.com/books?id=3HgQp6f9yGQC&q=%22Master+Direction+Center%22&pg=PA156 |format=Google Books |publisher=Air Force History Support Office |page=159 |isbn=9781428990272 }} Operating procedures for the ESS external sites were complete in March 1956,Memorandum 6M-4071 "Requirements for Operating Procedures for External Sites in the Experimental SAGE Subsector (ESS)" by M. DiCarlo-Cottone. (cited by Lincoln memo 6M-3797) and
System Operation Testing
From November 15, 1955, to November 7, 1956, three System Operation Tests were conducted{{r|CCS-ESS}} which used voice "Ground-to-Air" communication from the Barta control room to aircraft outfitted with SAGE receivers{{cite book|title=From Whirlwind to MITRE: The R&D Story of the SAGE Air Defense Computer|publisher=MIT Press|isbn=9780262264266|url=https://books.google.com/books?id=dxZVbxcf_IoC|page=374|access-date=2015-05-18|date=2000-10-10}} (F-86 interceptors modified to F-86L models in "Project FOLLOW-ON".){{r|NORAD1956-7}} Test teams included employees of Bell Telephone Laboratories, Western Electric-ADES, IBM, the RAND Corporation, and Lincoln Labs' Division 6, Division 3, & Division 2{{r|RedmondSmith}} (Division 6 had been created for ESS support.){{cite book|title=The United States Air Force and the culture of innovation 1945-1965|author=Stephen B. Johnson|publisher=DIANE Publishing|isbn=9781428990272|url=https://books.google.com/books?id=3HgQp6f9yGQC|page=151|access-date=2015-05-18}}
The North Truro P-10 AN/FST-2 was moved to Almaden Air Force Station (M-96){{circa|lk=no|1957-8}}Cite NORAD Historical Summary |year=1956-7 |quote=Project FOLLOW-ON provided the third improved model -the F-86L --which was an F-86D with modernized electronic gear and wings with slatted leading edges. … Project FOLLOW-ON was to make the F-86D compatible with the new [pre-SAGE] AN/GPA-37. … Eleven squadrons were meeting Project FOLLOW-ON schedules by 30 June 1957. and on August 7, 1958, control of an airborne BOMARC missile that had malfunctioned transferred from the "Experimental SAGE Sector" to a Westinghouse AN/GPA-35 Ground Environment system{{Where|reason=Cape Canaveral or Santa Rosa Island BOMARC launch?|date=August 2014}} and the missile crashed into the Atlantic Ocean.{{Cite report |last=McMullen |first=R. F. |date=15 Feb 1980 |title=History of Air Defense Weapons 1946–1962 |volume=ADC Historical Study No. 14 |publisher=Historical Division, Office of information, HQ ADC |page=312 }} By December 31, 1958, ADC Manual 55-28 described the Model 3 SAGE System. http://www.airforcehistoryindex.org/data/000/461/733.xml |quote=SAGE SYSTEM DESCRIPTION, MODEL 3, ADCM 55-28 COMPLETED AND PUBLISHED
{{External media
|image1=[http://www.ieeeghn.org/wiki/index.php/Milestones:Semi-Automatic_Ground_Environment_(SAGE)_1951-1958 Military operators at ESS consoles]
|image2="[http://www.ll.mit.edu/about/History/capecodprototype-2.html "Prototype intercept monitor room in the SAGE direction center in MIT's Barta building.]" [dated February 19, 1955 at archive[dot]today[slash]tPdY2]
}}
1959 Experimental Testing
"To prove out the revised SAGE computer program" for Automatic Targeting and Battery Evaluation and ADDC-AADCP crosstelling, a "SAGE/Missile Master" test was conducted beginning in September 1959 with communications between the ESS XD-1 and Martin AN/FSG-1 Antiaircraft Defense System equipment at Fort BanksCite NORAD Historical Summary |year=1958 |period=July–December planned for the CONAD Joint Control Center at Fort Heathlst Ind, (ADC to CONAD, "Site Adaptation Plans for CONAD Joint Direction Centers,"
22 Oct 1957), CINCNORAD to C/S USAF, 1 Nov 1957 [cited by the NORAD Historical Summary for 1957 July–December)—a "SAGE ATABE Simulation Study" (SASS) was also completed 1959–60 by MITRE Corporation.{{cite web|url=http://deepblue.lib.umich.edu/bitstream/handle/2027.42/4298/bab9742.0001.001.pdf?sequence=5|publisher=deepblue.lib.umich.edu|access-date=2015-05-18}}