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Lincoln Laboratory Origins
The story of Lincoln Laboratory begins with George Valley. An associate professor in the MIT Physics Department, Valley was well known for his concern over nuclear weapons. In 1949, after learning of the Soviet atomic bomb, Valley became worried about the quality of U.S. air defenses. Conversations with other professors led him to conclude that the United States had virtually no protection against nuclear attack.
In his concern over the possibility of nuclear attack, George Valley was like many Americans. But in his desire to address the problem, he was unique. Valley decided to make the task of securing U.S. air defenses his personal responsibility.
Valley was in an excellent position to evaluate U.S. air defenses. As a member of the Air Force Scientific Advisory Board (SAB), he was able to arrange a visit to a radar station operated by the Air Force Continental Air Command. What he saw appalled him. The equipment had been brought back from World War II and was inappropriate for detecting long-range aircraft. Moreover, the operators had received only minimal instruction in the problems of air defense. He was particularly struck by the site's use of high-frequency (HF) radios; the quality of HF communications is dependent on the state of the ionosphere, which can vary over time and would be severely disturbed in the event of a nuclear explosion.
Following his visit to the radar station, Valley collected more information on U.S. air defenses, none of it reassuring, and then called Theodor von Karman, chairman of the SAB. Von Karman asked Valley to put his concerns in writing, which he did in a letter dated November 8, 1949.
Von Karman relayed Valley's concerns to General Hoyt Vandenberg, the Air Force chief of staff. Vandenberg instructed his vice chief of staff, General Muir Fairchild, to take immediate action. By December 15, Fairchild had organized a committee of eight scientists, with Valley as the chair, to analyze the air defense system and to propose improvements. On January 20, 1950, the committee, officially named the Air Defense Systems Engineering Committee (ADSEC) but informally known as the Valley Committee, began to meet weekly.
The Valley Committee
The members of the Committee agreed to begin their study with a set of basic assumptions about hostile aircraft and U.S. air defenses. They agreed that a Soviet bomber would most likely fly over the north polar region at high altitude and then descend as it approached its target. While the aircraft flew at high altitude, it would be able to detect ground radar before the radar could detect the aircraft. The bomber could then descend to a low altitude, where it could fly under the beam of the radar and be virtually undetectable. The committee determined that, to attack a city in the United States, a Soviet bomber would need to fly at low altitude for only about 10% of its journey. Therefore, the range penalty for low-altitude flight would be small. If aerial refueling were performed near the Arctic Circle, the entire United States could be vulnerable to a Soviet attack. Spaced as they were, the then-existing GCI radars gave virtually no protection. A low-flying aircraft could find a clear path to almost every city in the United States.
The Committee determined that the weakest link in the nation's air defenses was the radars that were supposed to detect low-flying aircraft. Each radar's range was limited by its horizon. By flying at low altitude, aircraft could hide from the widely spaced GCI radars. Since air-based or space-based surveillance was not an option in 1950, the only solution was to install ground-based radar systems close together.
In 1950, this solution was ambitious. But fortunately for the future Lincoln Laboratory, the Committee continued to evaluate the problem and reduced it to two major issues. First, in order to interpret the signals from a large number of radars, there had to be a way to transmit the radar data to a central computer at which the data could be aggregated. Second, since the objective was to detect and intercept the hostile aircraft, the computer had to analyze the data in real time.
When Valley called several computer manufacturers to inquire about the possibility of using one of their systems to test his ideas, he was dismissed as a crackpot. Real-time operation was simply inconceivable in 1950. However, the answers to the problems of data transmission and of real-time operation were waiting to be addressed nearby. At the Air Force's Cambridge Research Laboratory, John Harrington had developed an early form of modem known as the digital radar relay, which was capable of converting analog radar signals into digital code that could be transmitted over telephone lines. Also, at the Servomechanisms Laboratory on the MIT campus, Jay Forrester was heading up a group that was developing the world's first real-time computer.
Valley needed a computer fast enough to handle real-time data analysis. As he began his search, Valley ran into Professor Jerome Wiesner, then associate director of the Research Laboratory of Electronics, and learned that the computer he required was already on the MIT campus. It was in the Servomechanisms Laboratory, and it was about to be abandoned by its sponsor.
During World War II, the emphasis in the Servomechanisms Laboratory had been on developing gun-positioning instruments. After the end of the war, the laboratory had begun a program to demonstrate a flight simulator for the Office of Naval Research. Plans had called for this device to simulate virtually every aircraft then in existence. Because this would require a powerful computer, the Servomechanisms Laboratory had begun to develop its own computer, code-named Whirlwind.
From his talk with Forrester, Valley was convinced that Whirlwind was suited to the ADSEC project. From then on, Forrester was a regular participant in ADSEC. Whirlwind was in a relatively early stage of its construction, with only 5 words of random-access memory and 27 words of programmable read-only memory. Yet its high speed and 16-bit word length made it adequate for ADSEC to test the feasibility of the concept that radar data could be transmitted to a computer via the digital radar relay, and that the computer could respond to the information in real time and direct an interception.
Forrester promptly began preparing to receive and process digitized radar signals. The feasibility demonstration of the radar/digital-data concept took place at Hanscom Field in September 1950. The radar, which was an original experimental model of a microwave early-warning unit built by the wartime MIT Radiation Laboratory, closely resembled the radars used in the D-Day invasion of Normandy. While military observers watched closely, an aircraft flew past the radar, the digital radar relay transmitted the signal from the radar to Whirlwind via a telephone line, and the result appeared on the computer's monitor. The demonstration was a complete success and proved the feasibility of ADSEC's air defense concept.
The demonstration at Hanscom Field signaled the end of the first phase of ADSEC's work. The committee's focus shifted from evaluation to implementation; a laboratory dedicated to air defense problems began to be discussed.
On November 20, 1950, Louis Ridenour, chief scientist of the Air Force, wrote in a memo to Major General Gordon Saville, deputy chief of staff for development in the Air Force, "It is now apparent that the experimental work necessary to develop, test, and evaluate the systems proposals made by ADSEC will require a substantial amount of laboratory and field effort."
Ridenour's memo was the first document to propose a laboratory dedicated to air defense research. He estimated that such a laboratory would require a staff of about 100 and a budget of about $2 million per year. (During the 1950s, Lincoln Laboratory actually would have a staff of about 1800 and an annual budget in excess of $20 million.)
A few weeks later, on December 15, Valley joined Ridenour for lunch at the Pentagon. Ridenour persuaded Valley that they should ask MIT to set up the electronics laboratory that could develop ADSEC's air defense ideas. Valley later recalled that he wrote a letter in about an hour and that Ridenour recast it in "appropriate general officer's diction." By four o'clock, the letter had been signed by General Vandenberg and was on its way to James Killian, Jr., president of MIT.
The Vandenberg letter to Killian contained the following text:
The Air Force feels it is now time to implement the work of the part-time ADSEC group by setting up a laboratory which will devote itself intensively to air defense problems…
The Massachusetts Institute of Technology is almost uniquely qualified to serve as contractor to the Air Force for the establishment of the proposed laboratory. Its experience in managing the Radiation Laboratory of World War II, the participation in the work of ADSEC by Professor Valley and other members of the MIT staff, its proximity to AFCRL [Air Force Cambridge Research Lab] and its demonstrated competence in this sort of activity have convinced us that we should be fortunate to secure the services of MIT in the present connection.
The air defense problem which faces the Air Force is of great importance to the people of this country. The problem is technically complicated and difficult. The Air Force must urgently increase its research and development effort in this area and in this we ask your help. I sincerely hope that you will be able to give the matter serious consideration.
Adapted from E.C. Freeman, ed., Technology in the National Interest, Lexington, Mass.: MIT Lincoln Laboratory, 1995.top of page