Chavez 1

An Analysis of the Semi-Automatic Ground Environment System in North America

Christopher A. Chavez

Collin County Community College

Chavez 2

Abstract

During the Cold War, the United States & Canada developed an air defense system for

protection against air attack by the Soviet Union. The goal of this research is to examine the

overall designing of this air defense system, and by doing so, it looks at the research, and

development of this air defense system: The Semi-Automatic Ground Environment System. Not

only is SAGE system explained, but also the reasoning behind why the necessity for such a

system. This research takes from context of multiple books for the overall timeline of the

development of the system from its preliminary stages at MIT during the Whirlwind Project

towards its final use with the North American Air Defense Command, and how the SAGE

system has impacted different technologies for personal/commercial use.

Chavez 3

Christopher Chavez

Doctor Kyle Wilkison

Honors History 1302 – S1H

22 February 2015

An Analysis of the Semi-Automatic Ground Environment System in North America

SAGE: The Semi-Automatic Ground Environment System. A military system expanding

all of North America that is capable of detecting enemy and domestic aircraft, directing combat

over the skies, and preventing harm to the American public. Developed by top American and

Canadian research scientists, companies, and engineers, this system was one of the marvels of

20th century. Costing more than the Manhattan project itself, what is it that makes SAGE such a

remarkable tool in the cold war? Why was there a necessity for it? How and why was this

developed? To understand the subject at hand, we need to understand why the United States’

needed to build such a system from the beginning: World War II.

The end of World War II changed the world drastically. Europe, along with the world

order previously held by it, was demolished. With virtually all of the European and Asian

continents in ruin, the world had only two super powers left to look towards: the United States

and the Soviet Union. Both civilizations had differentiating opinions, resulting in both Moscow

and Washington escalating towards inevitable international conflict. The Americans knew that in

order to combat the Soviets, they would need to turn to key military strategists in order to fight

the red menace.

Chavez 4

American military strategists were convinced that technology, especially air power,

could circumvent the globe from any nation. After the Japanese bombing of Pearl Harbor, the

safety that the Atlantic Ocean and Pacific Ocean previously provided was no longer considered,

and the United States would need to develop a plan for security both onshore and offshore. With

the Roosevelt and Truman administrations establishing a global network of US-controlled air and

naval bases, the United States could now detect and deter enemies long before reaching the

mainland. With the United States military now at its height of power both in the air and sea, this

left the United States with more opportunity to research new technologies to further increase

America’s security. This would lead to the development of SAGE.

The end of the 1940’s was the beginning push for a powerful air defense in the

continental United States. On April 8th, 1947, Colonel John B. Carey, one of the Army Air

Force’s most knowledgeable officers in air defense command, predicted that the Soviet Union

would be able to develop the means to have long-range bombers and atomic weaponry by 1955.

Warning that such a formidable enemy could be a threat to the security of the United States, he

proposed that project begin in November 1946 to have air defense capabilities by 1948.

However, because of the limited technological capabilities related to radar, as well as using the

outdated and expensive World War II defense systems, his plan was denied. The United States

did however use some of the World War II defense systems to protect strategic areas of interest

in the United States, but this defense was much weakened since it did not cover the whole

continental United States. This led way to the development of the Radar Fence Plan. (Schaffel

62)

The Douglas Aircraft Company was given the project of Research and Development.

Known as “RAND,” they would be given the task of creating an air defense system suitable for

Chavez 5

immediate needs but would still be flexible towards the adaptation of new technological

advances. RAND immediately began working at the end of 1946, they had a preliminary report

available in July 1947. Recommending a large investment of funding for the research and

development of air defense was the key point of their report, but could not estimate how much

funding was necessary towards this size of a project.

That same month, on July 16th, 1947, Congress passed the National Security Act

authorizing the establishment of an independent United States Air Force, separating itself from

the Army Air Force. This newly founded military branch’s main objective was to develop an air

defense plan. The plan was headed by the Air Force Communications Directorate, Major General

Francis L. Ankenbrandt. The primary goal was to design a system that would “prove a strong

deterrent to enemy air attack with conventional bombers by providing the best air defense system

available today.” The report create by General Ankenbrandt would call for the Radar Fence Plan,

otherwise known as “Project Supremacy.” (Schaffel 7)

Project Supremacy, if the Air Force received funding immediately, a radar warning and

control system could be operational as soon as 1953. The system would have 411 radar stations,

18 control towers in the continental United States that would be serviced 24/7 by 25,000 US Air

Force personnel and 14,000 Air National Guard radar specialists. It would cost over $600 million

over a 5 year period. They construction and purchase of radars and other equipment would cost

$388 million, while the remainder would cover expansion and other modifications. This plan

conflicted with the RAND project, but was approved on November 21st, 1947 by Air Chief of

Staff Spaatz. The Radar Fence Plan was sidetracked by the Bureau of Budgets as such a huge

appropriation of funding could only be enacted by a congressional vote.

Chavez 6

On September 3rd, 1949, an Air Force B-29 jet reported that there was unusually high

radioactivity over the northern Pacific Ocean near the Soviet Union’s Kamchatka Peninsula.

American and British scientists alongside the Atomic Energy Commission and Pentagon officials

confirmed that the Soviets tested, and successfully detonated, an atomic bomb on August 29th,

1949, nearly 6 years before Colonel John B. Carey’s prediction. This gave both a public and

congressional huge concern about the safety and air defense the United States provided against

the Soviet Union. (Schaffel 111)

The Air Defense System Engineering Committee (ADSEC) was created in December

1949 to study the technical aspects of continental air defense. The main purpose of the

committee was to study and make recommendations that were necessary to a U.S. air defense

system as well as designing a model of the best way possible to implement one with emphasis to

both the present technological capabilities and being economically stable. They immediately

began working on a solution, and in January of 1950, the committee chair, George Valley, found

that the Massachusetts Institute of Technology was working on Project Whirlwind, a system that

could interpret radar signals. (Smith 27)

Project Whirlwind was lagging however, as MIT’s research and development was not

suitable for the present military air defense needs. After eight months of ADSEC research into

Project Whirlwind, the committee found that a digital computer was necessary for air defense,

and that most of the system’s capabilities should be automated for fast response times. This led

to a partnership between the Air Force and MIT, and the research to push the Whirlwind system

into military applications was pushed further. (Smith 77)

The first testing of the Whirlwind system took place in the early summer of 1950, known

as the Bedford Tests. The Air Force implemented a microwave early warning (MEW) radar at

Chavez 7

Bedford Airport. The way the system was implemented is that once the MEW radars picked up

signals, it would send its data over telephone to the Whirlwind system. Data from the MEW

radars would be in binary numbers in frequency-multiplexed form and the narrow-band filters

inserted at the end of the Whirlwind’s system would demultiplex them so that the computer

could interpret the data. Once the data was interpreted, the Whirlwind computers would then

save the data to the buffer storage in microseconds, the fastest interpretation of radar data over

any hand plotting system used during World War II. (Smith 99)

The MEW Bedford radar was considered a failure, as it had repeated issues with testing

and successfully identifying any air craft, especially during less than favorable weather

conditions. The Bedford MEW radar would be implemented until May 15th, 1953, where it was

then dismantled. The Bedford MEW radar testing did however open new possibilities to even

better radar equipment, and the Whirlwind computer was upgraded at this time to 12-inch

diameter cathode-ray tube displays and being able to use a light gun versus the preliminary 5-

inch oscilloscopes displays. (Smith 79)

The Air Defense System Engineering Committee was created to find a solution to

the air defense problem, but it was never given the capabilities to put the actual solution into

effect. This led to ADSEC recommending that a new air defense project be put into effect, and

they categorized it into three phrases. First, Project Charles, an appointed study group, would

analyze the whole issue of air defense for the American continent at hand. Project Charles was to

be led by Dr. F. Wheeler Loomis of the University of Illinois, and was to primarily examine the

feasibility of an air defense laboratory. Second, the experimental radar tests would remain under

the management of MIT’s Research Laboratory of Electronics. Third, a new research and

Chavez 8

development lab would be put into function to bring together the first two aspects of the new air

defense project. (Smith 100)

Project Charles created a report stating that the present technology the United States and

Canada had were feasible for an air defense system, and proposed that MIT construct a

laboratory specifically for the purpose of air defense research. The Research and Development

(RAND) project as well as the Weapons System Evaluation Group (WSEG) supported the

conclusions made by the Project Charles report. Around December 1951, MIT instituted the

Lincoln Project. (Smith 102)

In autumn 1952, the Air Force was studying how to create an Air Defense system (known

as the Air Defense Automation Project) suitable for the continent. Basing their research on the

British Royal Navy’s Comprehensive Display System (CDS), the Air Defense Automation

Project could become true. (Packer 180 – 184) The CDS worked by using several radar systems,

and that hundreds of planes could be tracked and displayed to their respective locations where

radar feedback was analyzed. The British have used the CDS system since 1946, but it was not

connected to any network that could relay all radar information to each other – a system that the

Air Force wanted. The Air Force approached both the University of Michigan’s Willow Run

Research Center to correct the deficiencies the CDS system showed and apply it for a new

system: the Air Defense Integrated System (ADIS). While doing so, MIT’s Lincoln Laboratory

adamantly opposed such a project. (Schaffel 197-199)

ADIS’s original prospects were to design a network where rather than having a

centralized location for radar feedback, each respective combat center that received radar

feedback would exchange data amongst one another. The Lincoln Laboratory’s substitute for

ADIS was to instead use a centralized digital computer to receive the data from all radar

Chavez 9

locations rather than exchanging it amongst multiple locations. This system could be built by

1955, rather than ADIS’s 1956 prospects and could also work with newer advanced radar

technology and Boeing’s BOMARC intercept missiles (meaning the Lincoln system could

defend against both ballistic missiles and air bombers). The main threat during 1952 was the

Soviet Union using manned bombers since Soviet development and use of the Intercontinental

Ballistic Missile (ICBM) would not be available until the 1960s, the Air Force believed that the

Lincoln Project was ahead of its time. (Schaffel 199)

The RAND project considered the Michigan ADIS project to be much better for their

short term needs and could be improved after being placed in operation whereas MIT’s Lincoln

System was most promising for the 1960s after the Soviets develop the ICBM technology. The

RAND project wanted to have a dual-development effort by both MIT and the University of

Michigan, but the Air Force needed to support only one project. On April 10, 1953, the

University of Michigan’s efforts were canceled and the Air Force went along with MIT’s

Lincoln Transition System (redesignated as SAGE in 1954). (Schaffel 200-201)

The initial work used in designing the SAGE radar systems and computing technology

would be derived from the same work used by MIT’s Digital Computer Laboratory in the late

1940s – the Whirlwind Computer (as used in the MEW Bedford Tests). The new computing

technology, the AN/FSQ-7 (dubbed the Whirlwind II), was creating by the Lincoln Laboratory,

the Air Force Cambridge Research Laboratory, and the International Business Machines

corporation (IBM) for the air defense of the American Continent. (Schaffel 203-204)

The AN/FSQ-7 proved to be much better than the redundant Ground-Controlled Intercept

methods used during World War II. Instead of the old plotting board method that used airmen to

locate enemy and friendly aircraft, which was obviously too slow for high-speed air combat, the

Chavez 10

AN/FSQ-7 could process radar data instantaneously. The AN/FSQ-7 could also display all

weapons available for the sector that it supervised, whereby allowing airmen to coordinate air

combat in that sector. (Schaffel 203-204)

Overall, the SAGE system was remarkable for the time in its use. By presenting a clear

picture of the speed, location, and direction of all the planes (both enemy and friendly), using the

available signals from the radars, along with the Texas Towers, picket ships, early-warning

aircraft, and the Ground Observers Corps. There was some fault in the system at the time, as the

system could only provide the radar information and what weapons could be used but not

coordinate combat directly. The combat was left to the airmen operator, hence the semi-

automatic in Semi-Automatic Ground Environment. (Schaffel 204-206)

While the Lincoln Laboratory and IBM continued to build and improve the AN/FSQ-7,

there was a need for new operations the SAGE system could undergo (done via new programs

that could be used with SAGE.) The new influx of programmers were needed, so RAND created

an entity for the programmers, the System Development Corporation (SDC.) Although a part of

the Lincoln Laboratory, majority of these programmers were stationed in Santa Monica,

California. These programmers created programs that allowed SAGE to link with new

supersonic fighters, antiaircraft artillery, and Surface-to-Air Missiles. The Army had an issue

with the Air Force overseeing the use of antiaircraft and SAM missiles which are used by the

Army only. (Schaffel 207)

The Army staunchly opposed the SAGE system’s use of the Army’s new Missile Master

System, a semi-automatic fire-direction system intended to improve coordination in missile-

firing units. This Missile Master was a near duplication of SAGE, and the Air Force found the

Missile Master system to be unnecessary, even conflicting, with the SAGE system. The

Chavez 11

Secretary of Defense decided on June 1956 that SAGE would control all weapons for Air

Defense (including the Army’s antiaircraft artillery and SAM missiles) but the Army would still

have control and deploy their Missile Master system. This meant that SAGE would command the

Missile Master system in how it would coordinate the artillery and SAM missiles. (Schaffel 207)

The layout of SAGE’s air defense is by dividing the United States into eight air defense

regions, each commanded by a combat operations center. Each region would then be divided

(depending on region) and have sectors commanded by direction centers. SAGE used a three-

early warning line system to detect aircraft from afar. The lines were called: the Pinetree Line,

the Mid-Canada (McGill) Line, and the Distant Early Warning (DEW) Line. (MIT Lincoln

Laboratory) Each line worked in distance so that the DEW line would detect any aircraft from

the oceans surrounding the North American continent, the McGill Line on the border between

Alaska/Russia and America/Canada, and the Pinetree line would divide the United States up into

eight air defense regions.

The SAGE system was remarkable for its time. While this system never reached its full

potential due to the United States not being attacked by the Soviets, as well as the new threat of

Soviet ICBMs in the early-mid 1960s (making SAGE redundant near its deployment), it was

nevertheless a remarkable piece of machinery that could demonstrate the full capabilities

American research scientists and military operatives could pioneer in new technologies. This

system has led to many technological advances along the way, expanding the knowledge of the

internet, radar technology for commercial use, microwaves for personal use, and so much more.

Chavez 12

Works Cited

McMahon, Robert J. The Cold War: A Very Short Introduction. Oxford: Oxford University

Press. 2003. Print.

Schaffel, Kenneth. The Emerging Shield: The Air Force and the Evolution of Continental Air

Defense 1945 – 1960. Washington, D.C.: CreateSpace Independent Publishing Platform. 1991.

Print.

Redmond, Kent C. & Smith, Thomas M. From Whirlwind to MITRE: The R&D Story of the

SAGE Air Defense Computer. Cambridge: The MIT Press. 2000. Print.

Packer, J. (2013). Screens in the sky: SAGE, Surveillance, and the Automation of Perceptual,

Mnemonic, and Epistemological Labor. Social Semiotics, 23(2), 173-195.

"Semi-Automatic Ground Environment Air Defense System." MIT Lincoln Laboratory: History:

SAGE. Massachusetts Institute of Technology, 2014. Web. 15 Feb. 2015.