MIT Radiation Laboratory
World War II radar research organization at the Massachusetts Institute of Technology
Radiation Laboratory
Radiation Laboratory device depicting cavity magnetron and radar scope view of eastern Massachusetts
Emblem from the Rad Lab Series (1946)
EstablishedOctober 24, 1940 (1940-10-24)
Research typeClassified research on radar
BudgetUS$106.8M in total contract value ($1.87 billion in 2024)
Field of research
  • Microwave radar
  • Radar systems
Directors
Staff3,897 (Aug. 1945)
Alumni6,200
LocationCambridge, Massachusetts, United States
42°21′39″N 71°05′30″W / 42.3608°N 71.0917°W / 42.3608; -71.0917
Disbanded
December 31, 1945 (1945-12-31)
NicknameRad Lab
Affiliations
9 (2 from lab projects)
[1]

The Radiation Laboratory, commonly called the Rad Lab, was a microwave and radar research laboratory located at the Massachusetts Institute of Technology (MIT) in Cambridge, Massachusetts. It was created in October 1940 and operated until 31 December 1945 when its functions were dispersed to industry, other departments within MIT, and in 1951, the newly formed MIT Lincoln Laboratory.

The use of microwaves for radio and radar was highly desired before the war, but existing microwave devices like the klystron were far too low powered to be useful. Alfred Loomis, a millionaire and physicist who headed his own private laboratory, organized the Microwave Committee to look for improvements for these devices. In early 1940, Winston Churchill organized what became the Tizard Mission to introduce U.S. researchers to several new technologies the UK had been developing.

Loomis arranged for funding under the National Defense Research Committee (NDRC) and reorganized the Microwave Committee at MIT to study the magnetron and radar technology in general. Lee A. DuBridge served as the Rad Lab director. The lab rapidly expanded, and within months was larger than the UK's efforts which had been running for several years by this point. By 1943 the lab began to deliver a stream of ever-improved devices, which could be produced in huge numbers by the U.S. industrial base. At its peak, the Rad Lab employed 4,000 at MIT and several other labs around the world, and designed half of all the radar systems used during the war.

By the end of the war, the U.S. held leadership in a number of microwave-related fields. Among their products were the SCR-584, the finest gun-laying radar of the war, and the SCR-720, an aircraft interception radar that became the standard late-war system for both U.S. and UK night fighters. They also developed the H2X, a version of the British H2S bombing radar that operated at shorter wavelengths in the X band. The Rad Lab also developed Loran-A, the first worldwide radio navigation system, which originally was known as "LRN" for Loomis Radio Navigation.[2]

Origins

Pre-war radar development

During the 1930s, Britain, Germany, the United States, and other nations developed radio detection systems independently and under tight secrecy. Each country guarded its work as a potential war-winning advantage, unaware that rivals had reached similar capabilities.[3] Germany fielded sophisticated systems earliest: the Freya early warning radar, Seetakt shipborne sets, and the Würzburg gun-laying radar. One historian judged German equipment "generally about a year ahead of the Americans."[4] Britain established the first operational network, with Chain Home stations along its east coast providing aircraft detection at ranges exceeding 100 miles by 1939.[5] More importantly, Britain developed an integrated system for directing fighter interceptors that no other nation matched. When British and American officials compared notes in September 1940, they discovered that their longwave systems were virtually identical: Chain Home Low and the U.S. Navy's CXAM operated on the same frequency and shared key technical features.[6]

American radar development had split between two services with distinct priorities. The Naval Research Laboratory pursued detection on relatively long wavelengths, achieving the first American pulse radar detection of aircraft in December 1934 and installing production sets on capital ships by 1940.[7] The Army Signal Corps, under Major William Blair, took a different path. Blair was convinced that the precision required for anti-aircraft fire demanded the narrow beams that only microwave wavelengths could provide, and he directed his laboratory at Fort Monmouth to concentrate on this approach.[8] Using available microwave generators like the Barkhausen–Kurz tube and split-anode magnetron, Signal Corps researchers detected ships at 1,000 yards and vehicles at 250 feet, results far inferior to what the Navy obtained on longer wavelengths.[9] By 1936, the effort had reached a dead end, and researchers reluctantly adopted the Navy's pulse techniques.[10]

The advantages of microwaves were well understood by the British, German, and American programs: compact antennas that could fit in aircraft, narrow beams for precise tracking and clearer displays, and better detection of low-flying planes that slipped beneath longer-wavelength radars. But none had solved the fundamental problem of generating adequate power at centimeter wavelengths.[11] The klystron, the most promising American generator, generated roughly one watt at ten centimeters, insufficient for practical radar.[12]

The breakthrough came in February 1940, when British physicists John Randall and Harry Boot at Birmingham University invented the resonant cavity magnetron, generating kilowatts of microwave power at ten-centimeter wavelengths and representing a thousandfold improvement over competing technologies.[13] By August 1940, British researchers had demonstrated the magnetron tracking aircraft in flight.[13]

Mobilization of civilian science

The outbreak of war in Europe in September 1939 prompted discussions among leading American scientists about organizing civilian researchers for national defense. Vannevar Bush, president of the Carnegie Institution, James Conant of Harvard, Karl Compton of MIT, and Frank B. Jewett of the National Academy of Sciences met repeatedly during the winter of 1939–1940 to consider how to bring American scientific and engineering talent to bear on military problems.[14] In spring 1940, Britain sent physicist A. V. Hill to explore scientific cooperation with the United States and Canada, but Hill found his hands tied without authorization to disclose British secrets. He returned to London to press for formal exchange.[15] The rapid German offensives in Norway and the Low Countries, followed by the fall of France in June, transformed these preliminary discussions into urgent action.[16] As the Rad Lab's official historian observed, the collapse "shook Washington with only slightly less violence than London."[16]

First NDRC meeting among leaders of the U.S. Army, Navy, MIT, Caltech, and Harvard (June 1940)

Bush secured a fifteen-minute meeting with President Roosevelt on June 12, 1940, presenting a single-page proposal for a new agency to coordinate civilian research on military devices. Roosevelt approved immediately, and the National Defense Research Committee (NDRC) was established by executive order on June 27.[17][16] Senior military leaders welcomed the initiative: Army Chief of Staff George C. Marshall told Bush that approaching war would force military laboratories to concentrate on procurement, leaving critical research gaps that NDRC could fill.[16] The committee organized into five divisions, with Division D covering detection, controls, and instruments under Compton's direction.[18]

Compton established a microwave section in mid-1940, headed by Alfred Lee Loomis, a lawyer-turned-physicist who operated a private laboratory at Tuxedo Park where microwave experiments were already underway.[19][20] The section, known as the Microwave Committee, included industry representatives from Bell Labs, General Electric, RCA, Westinghouse, and Sperry, as well as Ernest O. Lawrence from Berkeley.[20] During summer 1940, committee members surveyed American radar efforts and concluded that microwave techniques offered significant potential, though they encountered the same fundamental obstacle British researchers had faced: the lack of a suitable high-power source.[21]

The Tizard Mission

1940 cavity magnetron

The fall of France in June 1940 made Allied scientific interchange urgent. Before July was out, President Roosevelt approved an exchange of military secrets based on a diplomatic proposal from British Ambassador Lord Lothian.[15] A British scientific mission headed by Henry Tizard, a university rector and scientific adviser to the Ministry of Aircraft Production, reached Washington in late August and early September 1940.[22] The mission members brought a black box containing blueprints and technical data, with authorization to disclose any secret information the British government possessed in exchange for American secrets.[23] Among their cargo was one of the Birmingham cavity magnetrons, which one official history later called "the most valuable cargo ever brought to our shores."[24]

The mission arrived before the Army and Navy had authorized NDRC to disclose information to them. The Army granted permission on September 12, and the Navy, in more limited form, four days later.[23] On September 19, E.G. "Taffy" Bowen, a radar scientist from Britain's Telecommunications Research Establishment, demonstrated the magnetron to members of the Microwave Committee. Subsequent tests at Bell Telephone Laboratories confirmed the device generated approximately 15 kilowatts at 10-centimeter wavelength—far exceeding any American microwave source.[25] On September 28–29, members of the British mission joined the Microwave Committee as guests of Loomis at Tuxedo Park, where they established priorities for microwave radar development: airborne interception radar for night fighters was designated the most urgent task.[24][26]

Laboratory establishment

A March 1940 meeting in Berkeley including Lawrence, Bush, Karl Compton, and Loomis

The committee concluded that exploiting the magnetron required establishing a dedicated central laboratory staffed by research physicists. Initial plans to locate the facility at Bolling Field in Washington encountered delays, and it became clear that NDRC lacked authority to operate laboratories directly but could contract with existing institutions.[27] Independent surveys by Bush and the Microwave Committee both identified MIT as the institution best positioned to provide the necessary space, scientific staff, and capacity for rapid expansion.[28][n 1] On October 17, 1940, they secured Compton's agreement to host the laboratory at MIT, though Compton had reservations and recused himself from the formal decision.[29][30]

NDRC's Steering Committee approved the contract on October 25, 1940, with initial funding of $455,000.[31][n 2] The laboratory was named "Radiation Laboratory," a title selected to suggest similarity to Ernest Lawrence's nuclear physics facility at Berkeley rather than reveal its radar mission.[32] Recruitment began immediately, drawing primarily on nuclear physicists familiar with high-frequency techniques from accelerator work. Lawrence declined the directorship but used his extensive network to recruit researchers, including Kenneth Bainbridge from Harvard and Lee DuBridge from the University of Rochester, whom NDRC appointed as director.[33]

In late October 1940, approximately 600 scientists gathered in Boston for a conference on applied nuclear physics. Loomis and Bowles organized laboratory visits and special seminars on microwave techniques. At an October 30 luncheon at the Algonquin Club, Loomis and Compton briefed about two dozen recruits who signed secrecy agreements before receiving details on the laboratory's mission.[34] Within weeks, the effort had attracted Isidor Rabi from Columbia, who brought students Jerrold Zacharias and Norman Ramsey, as well as Luis Alvarez and Edwin McMillan from Berkeley. On November 11, 1940, the laboratory held its first group meeting in Room 4-133 on the MIT campus, a secure 10,000-square-foot space surrounded by the institute's electrical engineering program.[35] By mid-December, approximately 30 physicists were at work, and a wooden penthouse laboratory had been erected on the roof of Building 6.[35][36]

Organization

Governance

Director Lee DuBridge in his Building 24 office

The laboratory operated as a civilian contractor under OSRD's Division 14, which was reorganized from the original Microwave Committee in November 1942.[37] Alfred Loomis chaired Division 14, which supervised the laboratory's work and coordinated radar research across multiple contractors. Lee DuBridge directed the laboratory itself, supported by two associate directors: Isidor Rabi oversaw scientific and technical matters, while F. Wheeler Loomis managed administrative operations beginning in January 1941.[38] One laboratory member characterized the division of labor succinctly: DuBridge said "Yes." Loomis said "No."[39]

DuBridge maintained a collegial management style, operating the laboratory as what he termed a "scientific republic" rather than imposing hierarchical control. A steering committee met weekly to review general tasks and set priorities, leaving implementation to individual research teams.[40] The steering committee drew members from leading universities across the country, reflecting the laboratory's role in aggregating top researchers at MIT.[41] MIT handled facilities, security, and fiscal administration, while technical direction remained with the laboratory's scientific leadership.[41]

The laboratory initially organized work around radar components. Early recruits chose specializations collaboratively, selecting transmitters, receivers, or antennas in what Rabi characterized as choosing sides "just like a baseball team."[42] This component-based structure evolved as specific system development projects grew in scale. As projects multiplied, the laboratory developed a functional division structure addressing different applications: airborne interception, fire control, navigation, blind bombing, and early warning systems. The steering committee established priorities among conflicting projects after consultation with service representatives.[43]

The laboratory's status as a civilian contractor managing classified military research represented a novel organizational model. OSRD maintained relationships with both Army and Navy through liaison officers who resided at the laboratory. The laboratory worked directly with military commands to understand operational requirements and deployed personnel to battlefronts and bases to refine systems and train operators.[44] Ed Bowles, the Microwave Committee's first secretary, served as expert consultant to Secretary of War Henry Stimson beginning in April 1942, advising on all radar matters including procurement, training, and operations.[44][45] Tizard Mission members Taffy Bowen and Denis Robinson remained at the laboratory as liaisons from its British counterpart, the Telecommunications Research Establishment.[46]

As the Rad Lab started, a laboratory was set up to develop electronic countermeasures (ECM), technologies to block enemy radars and communications. With Frederick E. Terman as director, this soon moved to the Harvard University campus (just a mile from MIT) and became the Radio Research Laboratory (RRL). Organizationally separate from the Rad Lab, but also under the OSRD, the two operations had much in common throughout their existences.

Personnel

Technical staff for radio frequency components (Group 53), led by Albert G. Hill

The laboratory grew from approximately 20 scientists in November 1940 to a peak of 3,897 employees in August 1945, comprising 1,189 staff members (scientists and engineers), 1,301 nonstaff men, and 1,407 nonstaff women.[47] Over the course of the war, the laboratory employed a cumulative total of more than 6,200 people.[47] The Rad Lab was the largest laboratory operated under OSRD, and comparable in scientific staffing to Los Alamos, the research laboratory of the Manhattan Project.[48][n 3]

Recruitment drew primarily on university physics departments, exploiting networks established through prewar accelerator research. Ernest Lawrence proved an effective headhunter, using his connections to attract researchers familiar with high-frequency techniques.[33] By 1945, sixty-nine academic institutions were represented on the staff.[49] Although physicists predominated, recruits came from fields including physiology, political science, architecture, music, optics, mathematics, anthropology, and astronomy.[40] Nevertheless, one observer noted, the laboratory remained "a physicist's world, run for, and as completely as possible by, physicists."[40]

Salary administration posed its own challenges: staff members on academic leave received salaries tied to their home institutions, while those recruited from industry commanded higher pay. Discrepancies grew pronounced enough that a 1942 restructuring authorized selective merit increases to prevent what administrators feared would be a collapse in morale.[50]

Microwave radar development depended heavily on young scientists whose training in the new techniques older researchers often lacked.[51] This created recurring tensions with Selective Service. In spring 1944, the Massachusetts State Selective Service Director demanded fifty men from the laboratory, which would have disrupted a substantial portion of its work. MIT President Karl Compton protested directly to Undersecretary of War Robert P. Patterson, writing that "nine tenths of the worries of my most effective colleagues have been spent on this subject" and that morale had reached "an all-time low."[51] Intervention by Vannevar Bush and OSRD secured the retention of the selected staff.[51]

As the draft depleted male technicians, draftsmen, and mechanics, the laboratory increasingly recruited and trained women. By war's end, roughly as many women worked in technical positions as in secretarial and clerical roles.[52] Although women comprised more than a third of the laboratory's nonstaff workforce by 1945, comparatively few held staff research positions.[n 4] Among the women working in research groups were:

  • Pauline Morrow Austin, who worked on LORAN after completing her MIT doctorate;[53]
  • Yael Dowker, who worked in the antenna group;
  • Monica Healea of the Vassar physics department;[53]
  • Wang Ming-chen, who conducted noise research;
  • Henrietta Hill Swope, who computed LORAN navigation tables and later directed the Navy Hydrographic Office's LORAN division.[54]

Government contracts

MIT received $106.8 million in OSRD research contracts, making it the largest university contractor and accounting for 23.1% of all OSRD research spending; 94% of MIT's government contracts supported radar research at the Radiation Laboratory.[55] OSRD contracts operated on a cost-reimbursement basis, covering direct expenses plus overhead calculated proportionally to the contractor's overall operations.[56] The laboratory operated under OSRD's "short form" patent clause, giving the government title to inventions rather than merely licensing them.[57]

OSRD's Division 14 supervised a broader network of radar research beyond the Radiation Laboratory itself, managing 136 contracts with 18 academic or private research institutions and 110 contracts with 39 industrial organizations for fundamental research, component development, systems development, and training equipment.[58] The radar program consumed $156.9 million across 183 contracts, with the Radiation Laboratory representing 64.9% of this total.[59]

Industrial collaboration

Industrial collaboration proved central to the Rad Lab and OSRD operations. From its inception, the laboratory worked closely with Bell Labs, General Electric, RCA, Westinghouse, and Sperry Gyroscope, who supplied components, collaborated on systems development, and exchanged technical staff.[60] As the laboratory expanded, it contracted research and development work to other institutions when projects required distinct expertise, placing liaison staff with these contractors.[60]

The transition from laboratory prototype to factory production proved more elaborate than initially anticipated. Physical duplication of a laboratory model did not assure duplication of laboratory performance; extensive engineering modifications were often necessary before equipment could function under field conditions.[61] The laboratory maintained contact with hundreds of manufacturers, subcontractors, and vendors. A producer of automobile locks went into production on waveguide elements; an automobile manufacturer built precision antenna mounts.[62] Each required indoctrination, detailed specifications, test equipment, and often assistance developing production methods before Army or Navy procurement could begin.

The laboratory also organized limited "crash" production of experimental units through the Research Construction Company, enabling rapid fielding of prototypes before full military procurement began.[60][63] This "red ticket" program addressed a gap neither military research groups nor procurement agencies were equipped to fill: the need for small quantities of new equipment in the months before production lines could deliver.[64] Between 1943 and 1945, crash procurements delivered over $30 million worth of equipment to the Army and Navy, representing approximately 22% of Division 14's total allocations.[65]

Facilities

The laboratory began operations in November 1940 in modest quarters: approximately 10,000 square feet in MIT's Building 4 and rooftop space atop Building 6.[66] Within months, the laboratory had spread across MIT's campus and into nearby buildings. Flight testing commenced at the National Guard Hangar at East Boston Airport in July 1941.[66][67]

The laboratory's dispersal accelerated through 1941. By early 1942, operations spanned five separate locations: the original spaces in Buildings 4 and 6, laboratories and shops borrowed from the Mechanical Engineering Department in Building 3, Building 24 (a permanent fireproof structure erected in autumn 1941), and the old Hood Milk Company Building on Massachusetts Avenue two blocks from the main campus.[68][66] This fragmentation across 111,000 square feet of scattered space created coordination challenges as the laboratory's work intensified following Pearl Harbor.[68]

MIT built aggressively to keep up with personnel growth. Construction began in April 1942 on Building 22, a three-story temporary wooden frame structure that connected to Building 24 by an overpass, while Building 24 itself gained four additional floors and a penthouse.[69] Yet the laboratory continued to outpace available space. President Compton protested the ongoing practice of renting rooms in scattered Cambridge buildings and pushed for a third major structure.[70] Building 20, hastily designed and constructed of mill lumber with transite interior walls, rose in three wings in 1943, ready for occupancy in early 1944. Two additional wings followed as personnel continued to arrive.[70]

Flight operations similarly outgrew their initial quarters. Larger aircraft and the need for longer runways drove relocation from East Boston to Bedford Army Air Base in May 1944, where the laboratory occupied 43,000 square feet of hangar space.[67] The Army and Navy each established dedicated flight units to support testing operations: by war's end, the Navy's Special Project Unit Cast operated 35 aircraft with 138 personnel, while the Army's 1st Electronics Experimental Detachment maintained 60 aircraft with 166 personnel.[71] At its August 1945 peak, the laboratory's 3,897 employees worked across more than 400,000 square feet of laboratory and office space, a forty-fold expansion from its November 1940 origins.[71]

1
2
3
4
5
6
Rad Lab complex on MIT's main campus (1945)
1
Room 4-133 (Nov. 1940)
2
Roof Lab, Building 6 (Dec. 1940)
3
Building 24 (Nov. 1941–Jul. 1942)
4
Hood Milk (Mar. 1942)
5
Building 22 (May 1942)
6
Building 20 (Dec. 1943)

Field operations

The laboratory's crash production programs required sending personnel to combat theaters. Devices shipped before systematic testing needed scientists who had built them to handle installation and develop techniques for operational use.[72]

In September 1943, the laboratory established the British Branch of the Radiation Laboratory (BBRL) at Great Malvern, England, alongside the British Telecommunications Research Establishment. The official OSRD historian characterized BBRL as "pools of personnel, equipment, shop, and know-how" for modification, debugging, and field assistance rather than a laboratory in the traditional sense.[73] John Trump directed BBRL through most of its existence, reorganizing and expanding the operation in early 1944 to meet growing demands from the Eighth Air Force.[74] The branch eventually numbered approximately 100 personnel, with most deployed to air bases across Britain and the continent. Following the liberation of Paris in summer 1944, BBRL established an Advanced Service Base there.[75]

Plans for a similar field operation in the Pacific took shape in spring 1945, when OSRD organized a Pacific Branch under Karl Compton's direction. General Douglas MacArthur's headquarters approved the arrangement, but Japan's surrender came before the organization became fully operational.[76]

Early development

Early radar tests

The laboratory's founding mission comprised three projects, each addressing a critical gap exposed by the Battle of Britain. Airborne interception radar held first priority: the British considered a ten-centimeter set for nightfighters essential to stopping Luftwaffe bombing raids. Second came a long-range navigation system to guide bombers without requiring a signal from the aircraft itself. Third was a microwave gunlaying radar to direct anti-aircraft fire.[77] Staff members christened their Friday evening drinking sessions at the Commander Hotel "Project Four," after these three charter goals.[78]

The laboratory's first months tested whether microwave radar could work at all. Staff members spent November and December 1940 in an intensive effort to meet a self-imposed January deadline: build a working radar system around the British cavity magnetron.[79] The device presented formidable challenges. No American had built a microwave radar, and the short wavelengths required entirely new components. The laboratory's initial staff—physicists, not radar engineers—improvised as they went. On January 4, 1941, two days ahead of schedule, the first test system came to life on the roof of MIT's Building 6. An unwieldy transmitting antenna occupied one end of the rooftop, with the receiving aerial on the other, shielded from its counterpart by a loose screen cage. Within minutes of being switched on, the system registered echoes from the Boston skyline across the Charles River.[n 5]

The rooftop success proved microwave radar feasible but left critical engineering challenges unsolved. The test system used separate transmitting and receiving antennas, an arrangement impossible in aircraft. A practical airborne radar required a single antenna that could both transmit pulses and receive echoes. This demanded a transmit-receive (TR) switch that could shield the delicate crystal detector from the outgoing pulse's energy, then recover within microseconds to let in the faint returning signals. Jim Lawson, one of the few staff members with a strong amateur radio background, attacked the problem. By January 10, his team had fashioned a workable TR box using a klystron tube as a buffer. A second rooftop test that day demonstrated the first single-antenna microwave radar, prompting DuBridge to telegram Washington: "have succeeded with one eye."[80] Luis Alvarez later asserted that "if we had been paid in proportion to our contributions to the success of the first microwave radar program, Jim Lawson would have earned more than half the monthly payroll."[81]

Flight tests followed. On March 10, the experimental airborne interception equipment flew for the first time in a B-18 bomber equipped with a Plexiglas nose transparent to microwave radiation.[82] Results improved steadily over the following weeks. On March 27, Edwin McMillan's team flew again with Taffy Bowen and other scientists aboard. The equipment performed admirably, detecting aircraft and ships—and when the plane diverted to the submarine base at New London, Connecticut, it picked up surfaced submarines at three miles.[82][83] The discovery pointed toward a capability the laboratory had not originally prioritized.

Gunlaying

Work on the second charter project—anti-aircraft gunlaying—proceeded in parallel. In May 1941, officers from the Coast Artillery Board visited the laboratory and expressed keen interest in microwave fire control.[84] The following month, DuBridge approved purchase of a truck, and work began under Ivan Getting in an old hangar where the laboratory's Building 20 would later rise.[85]

The truck arrived in mid-July; by September, a 48-inch paraboloid dish with a spinning dipole had been mounted on an aircraft machine-gun turret supplied by General Electric.[85] The system used conical scanning and automatic tracking—techniques that allowed the radar to lock onto a target and follow it without human intervention. A rooftop demonstration on May 31 had already shown the approach worked; the mobile truck system, designated XT-1, aimed to package these capabilities for field use.[86]

XT-1 was not originally intended as a military weapon but as an experimental platform for further research.[84] Service trials changed that assessment. In late November 1941, the truck traveled to Fort Hancock, New Jersey, for initial tests. It returned to Cambridge after Pearl Harbor interrupted the schedule, then proceeded to Fort Monroe, Virginia, in February 1942 for formal evaluation by the Coast Artillery Board.[87] There it was coupled to the T-10 director, an electronic analog computer designed by Bell Telephone Laboratories that predicted where a target would be when shells arrived. The combination proved devastating. Over sixty tracking runs showed probable errors of less than one mil in angle and about twenty yards in range.[88] In firing tests against tugged targets, guns directed by XT-1 and the Bell predictor "shot down targets with as few as eight rounds, all without human intervention or visual contact with the target."[89]

The Coast Artillery Board concluded that XT-1 "is superior to any radio direction finding equipment yet tested... for the purpose of furnishing present position data to an anti-aircraft director."[88] On April 2, 1942, the Signal Corps ordered 1,256 copies, designating the production version SCR-584.[88] The order eventually grew to nearly 1,700 sets.[90]

Anti-submarine warfare

The laboratory's founding projects had emphasized aircraft interception and anti-aircraft fire control, reflecting the Battle of Britain's lessons about the threat of night bombing. By mid-1941, however, Britain had defeated the Luftwaffe's daylight offensive, and a different crisis demanded attention. German U-boats operating from French ports were sinking merchant ships faster than Allied shipyards could replace them. Longwave air-to-surface-vessel radar (ASV) existed but performed poorly against submarines: sea clutter cut detection ranges, and the radar's meter-length waves allowed U-boats to detect approaching aircraft in time to submerge before attack.[91]

In July 1941, Denis Robinson arrived from Britain's Telecommunications Research Establishment with instructions to redirect the laboratory toward anti-submarine radar. Robinson, whose family had already evacuated to Massachusetts, brought firsthand knowledge of the submarine war's urgency.[92] DuBridge began phasing out the original aircraft interception project and raising the priority of air-to-surface-vessel work.[93]

By fall 1941, the laboratory carried at least five ASV projects on its books, each tailored to different aircraft types.[93] Trials aboard the destroyer USS Semmes demonstrated shipboard potential: a prototype radar incorporating the Plan Position Indicator guided the vessel and three submarines safely into harbor through heavy fog, detecting buoys that visual lookouts could not see.[94] The Navy placed a production order with Raytheon for what became the SG radar, later called "one of the most widely used and effective of all shipboard radars."[95]

The shift from research to production accelerated after Pearl Harbor. In early 1942, German U-boats began Operation Paukenschlag, attacking virtually undefended American coastal shipping. In January and February, Army Air Forces planes without radar managed attacks against only four U-boats in 8,000 flying hours.[96] DuBridge made ASV his top priority. Ten B-18 bombers arrived at East Boston Airport for crash installation of microwave radar. The laboratory's model shop, the Research Construction Company, built fifty ground-based sets by hand for the Signal Corps; five of these became the first microwave ground equipment to see combat, deployed during the North Africa invasion in November 1942.[95][97]

Research Construction Company

Bridging the gap between laboratory prototype and factory production required an intermediary. Physical duplication of a breadboard model did not assure duplication of laboratory performance; extensive engineering modifications were often necessary before equipment could function under field conditions.[61] Yet neither military research groups nor procurement agencies were equipped to produce the small quantities of new equipment needed in the months before production lines could deliver.[64]

In September 1941, NDRC authorized a $300,000 contract for a Radar Model Shop, choosing the Research Corporation—a nonprofit organization devoted to supporting scientific research—as contractor.[98] The Cambridge Division of the Research Construction Company opened at 230 Albany Street with Ely Hutchinson as manager. Normal model shop work gave way to emergency production almost immediately. On December 17, 1941—ten days after Pearl Harbor—the Signal Corps ordered fifty sets of the SCR-582, a ground-based microwave radar. This "crash" order marked a departure from the original program and established a pattern that became the Research Construction Company's most useful function.[98] The laboratory's model shop built fifty ground-based sets by hand for the Signal Corps; five became the first microwave ground equipment to see combat, deployed during the North Africa invasion in November 1942.[95][97]

1942 reorganization

Pearl Harbor forced a reconsideration of the laboratory's purpose. During the last months of 1941 and the first months of 1942, staff debated whether the Radiation Laboratory should remain a small research organization or expand into engineering development and limited production. Some industrial representatives on the Microwave Committee opposed further growth, arguing that the laboratory was encroaching on industry's legitimate sphere and was not properly constituted for engineering work.[99] Alfred Loomis led the opposing view, believing firmly in the necessity of a "follow through" policy; the Microwave Committee ultimately recommended "a severalfold increase in the number of scientists and engineers engaged in its research and development program."[99]

Expansion demanded reorganization, and several proposals circulated. Taffy Bowen proposed reorganizing to match the British Telecommuniations Research Establishment: three independent laboratories devoted to ground, shipboard, and airborne systems respectively.[100] The components groups opposed this "vertical" organization, preferring to remain intact under a "horizontal" structure. They argued that separating their work from systems development would remove the stimulus that came from seeing results go into practical use.[100]

DuBridge's compromise, adopted in March 1942, combined both approaches. Related components groups and basic research efforts were brought together into divisions, while systems groups working on related applications came under single divisional heads. The number and scope of divisions were determined not by abstract considerations but by available leadership: the Director and Steering Committee analyzed the available personnel, decided who the top scientists were, and built the organizational structure around them.[101]

The reorganization created ten divisions. Rabi headed Division 4 (Research); Robert Bacher took Division 6 (Receiver Components); Luis Alvarez led Division 7 (Special Systems); Kenneth Bainbridge directed Division 8 (Ground and Ship Systems); Louis Ridenour ran Division 9 (Airborne Systems); and Lauristen C. Marshall managed Division 10 (Systems Engineering and Production).[101] The Loran navigation group under Melville Eastham, initially listed as a special project, soon became Division 11.[102]

By the end of 1942, staff had grown from the original thirty to over a thousand, and the laboratory occupied fifteen buildings across the MIT campus.[24] The pattern established in these months—identify an operational problem, develop a prototype solution, support field deployment while handing production to industry—defined the laboratory's approach throughout the war.

Radar navigation and control systems

The laboratory developed several systems that, while not weapons themselves, enabled combat operations that would otherwise have been impossible. These ranged from navigation aids covering much of the globe to precision landing systems and the surveillance radars that coordinated air operations over entire theaters.

Long-range navigation (LORAN)

Long-range navigation the last of the three original projects assigned to the Radiation Laboratory. In October 1940, Alfred Loomis proposed a hyperbolic navigation system in which synchronized radio pulses from pairs of ground stations would enable ships and aircraft to fix their position by measuring the difference in arrival times. The scheme was identical in principle to the British Gee system, about which members of the Tizard Mission were only imperfectly informed; Loomis appears to have arrived at the concept independently.[88]

The navigation group, established in January 1941 under Melville Eastham, initially planned to work at 30 MHz. During the summer, however, the group discovered that waves reflected from the ionosphere at lower frequencies were stable enough for accurate fixes at ranges exceeding a thousand miles—far beyond what direct ground-wave propagation could achieve.[103] By September 1941 the group had shifted to 2 MHz and developed the precision timing circuits that became the system's foundation. The name emerged from "long-range navigation," first abbreviated LRN and later expanded to Loran.[104]

The first full-scale test came in June 1942, when a Navy blimp carried an experimental receiver over the Atlantic. The results aroused intense service interest. Laboratory engineers, traveling through U-boat-infested waters without waiting for escort, supervised installations at stations in Nova Scotia, Newfoundland, Labrador, and Greenland during the fall and winter of 1942.[105] The four southernmost stations began regular service on October 1, 1942, inaugurating the first Loran chain. By July 1943 the system had been turned over to the U.S. Coast Guard and the Royal Canadian Navy.[106]

The discovery that sky-wave signals could synchronize stations as far as 2,000 kilometers apart led to SS (sky-wave synchronized) Loran, which extended coverage deep into Central Europe for RAF Bomber Command night operations beginning in October 1944.[107] During 1944 and 1945, Coast Guard installations covered a large area of the Pacific at the direction of the Joint Chiefs of Staff. By war's end, 70 Loran stations and 75,000 receivers provided navigation for approximately 30 percent of the Earth's surface.[107] The navigation group that accomplished this never exceeded 73 people.[106]

Loran remained in service longer than any other wartime radio navigation system. The 150-meter band system continued as the postwar standard, designated Loran A. A low-frequency successor, Loran C, became operational in 1957 and served marine and aviation users into the twenty-first century.[107]

Blind landing (GCA)

Before the war, several agencies had developed instrument landing systems, none satisfactory for military purposes. Existing approaches required special equipment in the aircraft and demanded interpretation by pilots returning fatigued from combat.[108]

In August 1941, Luis Alvarez watched a rooftop demonstration of the gun-laying radar and realized that if a radar could track aircraft accurately enough to direct anti-aircraft fire, it should be able to guide pilots to safe landings. He envisioned a system in which ground controllers would "talk" pilots down by comparing the aircraft's radar-measured position against an ideal glide path.[109] Initial tests with the XT-1 prototype failed: the radar beam sometimes detected the aircraft's reflection off the ground, placing it below the runway without warning.[110]

Alvarez and Alfred Loomis worked out the solution. The resulting Ground Controlled Approach system used three separate radars: a 10-centimeter search set feeding a Plan Position Indicator to manage traffic, and two 3-centimeter sets with narrow fan-shaped beams—one scanning vertically for elevation, the other horizontally for azimuth.[110] The shorter wavelength eliminated ground reflections. Lawrence Johnston served as project engineer, with Gilfillan Brothers manufacturing the sets.[110]

A single Mark I system, tested under field conditions in England in 1943, proved so successful that demands came from all theaters. By the time the Mark III appeared, crews had made more than 2,000 successful blind landings.[110] Sets saved numerous bombers returning damaged from Germany. GCA operated on Iwo Jima, Leyte, Okinawa, and other Pacific bases; the Iwo Jima installation saved several B-29s returning from raids on Japan.[111]

The system's greatest demonstration came after the war. During the Berlin Blockade of 1948–1949, continuous flights supplying the city would have been impossible without GCA to handle landings in persistent poor weather.[112] Ground-controlled approach remains the basis for tower-assisted approaches at airports worldwide.

Microwave early warning (MEW)

In the months following Pearl Harbor, when Japanese air attack on the West Coast seemed possible, Alvarez conceived a high-power microwave radar for long-range early warning. Microwave Early Warning sets would combine the detection range of existing meter-wave systems with the resolution and low-altitude coverage that only microwaves could provide.[113]

The design centered on an innovative antenna. A horizontal parabolic reflector 7.6 meters wide, fed by a linear array of 106 dipoles, produced a beam only 0.8 degrees wide that could detect aircraft at ranges exceeding 175 miles.[114] Alvarez solved the problem of unwanted side lobes by reversing alternate dipoles along the array, an arrangement that became standard in postwar search radars.[115] The complete system weighed 66 tons and required eight trucks to transport.[114]

Only a few MEWs were built, all hand-crafted at the laboratory. Set number one began operating at Start Point, Devon, in January 1944 and quickly demonstrated its value to both air forces.[114] Shortly after installation, operators detected a large formation 270 kilometers out over the Atlantic: fourteen B-17s with 140 men, hopelessly lost and preparing to ditch. A telephone call to a nearby station that could not see the aircraft allowed controllers to advise the bombers of their true position and vector them home.[116]

During the D-Day operations, the Start Point MEW performed three types of missions: maintaining fighter patrols off the Brest peninsula, directing fighter-bombers to targets, and aiding rescue of pilots downed in the Channel.[117] A second MEW, converted to a mobile configuration in eleven days, landed on Omaha Beach six days after the invasion and accompanied advancing armies into France.[118] When V-1 attacks began, the English MEW relocated to Hastings, where it detected incoming bombs at 130 miles—more than twenty miles beyond any other radar. This provide crucial minutes for aircraft interceptors in Operation Diver.[119]

In the Pacific, MEW number four reached Saipan in late 1944. After low-flying Japanese fighters surprised the B-29 base in November, telegrams from Washington ordered immediate installation. Established atop Mount Tapochau by New Year's Eve, the set picked up a January 3 raid at 200 kilometers and enabled interception.[120] General Orvil Anderson declared: "Within the range of MEW every one of my fighters is worth two outside its range."[121]

Airborne early warning (Project Cadillac)

Shipboard search radar could not see beyond the horizon. Japanese pilots exploited this limitation by approaching American task forces at low altitude, beneath the beams of long-wave search sets; in 1944, this technique enabled the kamikaze attacks that made extending the fleet's radar range a top-priority Navy problem.[122]

The solution was to put the radar in an aircraft flying high enough to see over the horizon. An interservice committee had recommended such a system in June 1942, but competing priorities kept the effort modest until the kamikaze threat emerged. In February 1944, the Bureau of Aeronautics formally requested the NDRC to establish what became Project Cadillac, named for the Maine mountain where experimental equipment was tested.[123] Jerome Wiesner led the effort at the laboratory.[124]

The project required integrating several types of electronic equipment into a functioning system—the word began to take on its modern meaning.[120] A TBM-3 torpedo bomber was redesigned to carry 2,300 pounds of equipment. An 8-foot bulbous radome housing the antenna was mounted between the aircraft's wheels; the ball turret, armor, and armament were removed.[123] The radar operated at 10 centimeters with peak power of one megawatt. A television-derived relay link transmitted the radar picture to a Combat Information Center aboard a ship, where operators could monitor aircraft over a wide area.[120]

Cadillac became the largest undertaking in the laboratory's history. Nine of eleven divisions contributed; at the summer 1945 peak, approximately 20 percent of all technical staff time went to Cadillac, along with 160 Navy officers and enlisted men.[123] Direct outside purchases for the project constituted 12 percent of total laboratory expenditures over its entire five-year existence.[125]

The first production system was delivered in March 1945, thirteen months after the initial request. Trials aboard the carrier Ranger established the system's value: single aircraft flying at 500 feet could be detected at 45 to 70 miles, roughly twice the range of the best shipboard sets. Destroyers were detected at 200 miles with the aircraft at 20,000 feet, a sixfold improvement.[126]

Cadillac arrived too late to affect the war's outcome. In June 1945, with the first system reaching the fleet, the Navy requested a second version: Cadillac II placed a combat information center in a four-engine bomber, eliminating the need for a ship.[127] Seventeen systems were delivered by October 1945. The project was the direct forerunner of the Airborne Warning and Control System (AWACS).[124]

Major combat systems

Anti-submarine warfare

German U-boats nearly severed Britain's Atlantic lifeline in the winter of 1942–43. Wolf packs attacked convoys at night, surfacing to use their high speed for pursuit and escape. Existing longwave radar could detect surfaced submarines, but the meter-length waves also triggered receivers aboard U-boats, giving crews warning to submerge before aircraft arrived.[91] In the first twenty days of March 1943, U-boats sank ninety-five Allied ships—more than half a million tons—while the Allies destroyed only twelve submarines, barely half Germany's monthly production.[128]

SG radar console, including Plan Position Indicator (PPI) display

Microwave radar changed the equation. The laboratory's 10-centimeter ASV (air-to-surface-vessel) sets detected surfaced submarines before U-boat receivers could warn of approaching aircraft; German technology could not yet detect the shorter wavelengths. The SG radar provided similar capability for escort vessels, displaying targets on a Plan Position Indicator that showed bearing and range at a glance.[95] At the end of March 1943, Liberators equipped with extra fuel tanks and microwave radar, navigating by Loran, established a shuttle service between Britain, Iceland, and Newfoundland, closing the mid-Atlantic gap where wolf packs had operated beyond the reach of shore-based aircraft.[129] By war's end, Loran stations covered approximately 30 percent of the Earth's surface and served 75,000 aircraft and surface vessels.[130]

The results were immediate. In May 1943, the Allies destroyed forty-one U-boats while losing forty-five merchant ships—a ratio unthinkable two months earlier.[131] Admiral Karl Dönitz withdrew his submarines from the North Atlantic on May 24.[131] British naval historian Stephen Roskill later judged that centimetric radar "stands out above all other achievements because it enabled us to attack at night and in poor visibility."[132]

Blind bombing

The Eighth Air Force's strategic bombing campaign faced a simple problem: weather. Cloud cover over Germany was persistent and thick. Severe storms swept the corridor between London and Berlin every three days on average.[133] During the winter of 1942–43, heavy bombers could operate only one or two days per month.[134]

The British had developed H2S, a 10-centimeter radar that displayed terrain on a scope, allowing bombers to navigate and release weapons through overcast. The Radiation Laboratory built H2X, a 3-centimeter version with sharper resolution and immunity from German detection equipment.[135] On November 3, 1943, nine B-17 Pathfinders equipped with H2X led sixty bombers against the Wilhelmshaven docks—a target that eight previous visual missions had missed entirely.[134][136]

8th Air Force bombing through clouds in Bremen, Germany, Nov. 1943

H2X increased the tempo of operations. In November 1943, no day's weather forecast would have warranted a visual attack on Germany, yet the Eighth attacked German targets nine times.[137] In December, the Eighth dropped more bombs than in any previous month and for the first time exceeded RAF Bomber Command's tonnage.[137] By year's end, the original twelve H2X aircraft were leading 90 percent of American bombing missions; bomb tonnage dropped via H2X in the last two months of 1943 exceeded the total dropped by visual sighting over the entire year.[134] From mid-October 1943 to mid-February 1944, the official Army Air Forces history notes, "the story of daylight strategic bombing from the United Kingdom is essentially the story of an experiment in radar bombing."[133]

H2X accuracy was poor by precision-bombing standards: it had a circular error probable of roughly two miles.[138] However, air planners concluded that "it seemed better to bomb low-priority targets frequently, even with less than precision accuracy, than not to bomb at all."[133] General James Doolittle acknowledged the limitations but remained committed: he "was willing to send 100 planes to do a 10 plane job" rather than wait for better equipment.[138]

H2X radar allowed B-24s to bomb refineries through smoke

The radar proved essential when strategic bombing turned to oil. On June 8, 1944, General Carl Spaatz ordered that denying oil to Germany would be the primary strategic aim—an order that remained in force until the war ended.[139] German defenders responded with smoke screens that made visual bombing of refineries "almost impossible."[140] The Fifteenth Air Force relied on H2X to attack the Ploești refineries through artificial smoke, eventually flying twenty daylight missions that denied the Germans an estimated 1,800,000 tons of crude oil.[141] By September 1944, German oil production had fallen to 23 percent of pre-campaign levels; of ninety-one installations still in German hands, only three were in full production.[142]

The linear array antenna developed for MEW found a second application in Eagle (AN/APQ-7), a blind bombing radar that used a 16-foot version to achieve a beam width of 0.4 degrees, narrow enough to resolve individual city blocks. Delayed by competing priorities and skepticism about the unconventional antenna, Eagle reached combat too late for extensive use in Europe, but equipped an entire wing of B-29s in the Pacific. On July 6–7, 1945, Eagle-equipped aircraft destroyed 95 percent of the Maruzen oil refinery, prompting General LeMay to call the strike "the most successful radar bombing of this command to date."[143][144]

Anti-aircraft fire control

Existing anti-aircraft systems in 1941 relied on searchlights to illuminate targets and human operators to track them. The process was slow and inaccurate; guns fired static barrages hoping bombers might fly into the flak.[145] German chaff and jamming rendered longwave fire-control radars nearly useless.[146]

Technician with SCR-584 dish

The laboratory's physicists proposed something more ambitious. While parallel British and Canadian programs aimed merely to add microwave radar to existing manual tracking, Louis Ridenour pushed for a fully automatic system. He assembled a team including Ivan Getting and Lee Davenport to develop a radar that would lock onto targets and follow them through evasive maneuvers without human intervention.[145]

The cornerstone was conical scanning, a technique in which a rotating antenna beam traced a cone in space. A target on axis returned a constant signal; any deviation produced amplitude variations that servomotors converted into corrections, automatically realigning the radar.[145] To test the concept, the team conscripted a servo-driven gun turret from General Electric's B-29 program and mounted their prototype in the Building 6 Roof Lab. Local air traffic was too sparse to provide reliable test targets, so Harvard geologist Dave Griggs agreed to fly his personal Luscombe Aircraft around Cambridge for $10 an hour, simulating an enemy.[147] On May 31, 1941, with Davenport in the back seat radioing observations, the team achieved the first automatic tracking of an aircraft by radar.[148]

When tested at Fort Monroe in February 1942, the prototype located objects within six-hundredths of a degree and twenty yards in range.[149] The Army ordered over 1,200 units, designating the radar SCR-584.[150] Connected to the Bell Labs M-9 predictor, which calculated where targets would be when shells arrived, the system transformed anti-aircraft gunnery. Nearly 1,700 sets were produced.[151]

The SCR-584's most dramatic success came against the V-1 flying bomb. Beginning in June 1944, Germany launched thousands of pilotless weapons against London. The SCR-584, combined with the proximity fuze—a miniature radar in the shell nose that detonated when near a target—eliminated the need for direct hits.[151] Before this combination entered service, anti-aircraft guns destroyed fewer than one V-1 in four; afterward, they destroyed approximately 85 percent of targets engaged.[152][153]

Flak, a 1945 Army Air Forces film explaining SCR-584 fire control

The SCR-584 proved equally versatile in offense. Modified versions guided tactical aircraft to targets that pilots could not see. In the system developed at the British Branch of the Rad Lab, ground controllers tracked incoming fighters and radioed corrections that put them onto camouflaged targets with near-infallibility, eliminating the problems of target recognition that had plagued close air support.[154] A demonstration on June 25, 1944 made the case dramatically. At a site near Malvern, observers watched through a loudspeaker system as a controller directed Typhoon pilots by radio. Just as the countdown reached zero, the squadron leader wheeled into a 120-degree turn and led his flight in a steep dive directly toward the watching party—having located the target solely through radar guidance.[155]

The first operationally modified SCR-584 reached Normandy on July 9.[156] During the Ardennes counteroffensive, with the ground covered in snow and friend indistinguishable from foe, MEW and SCR-584 working together provided aircraft with the navigational control to attack German armor through overcast skies.[157]

Demobilization and legacy

Postwar transition

When the Radiation Laboratory closed on December 31, 1945, the armed services moved quickly to preserve its capabilities. The laboratory's Basic Research Division continued under OSRD funding through the spring of 1946, then became part of MIT on July 1 as the Research Laboratory of Electronics (RLE).[158] The Joint Services Electronics Program provided $600,000 annually for basic, unclassified research, with the services seeking "a laboratory from which the military services can draw competent technical help at critical times."[159] RLE opened with seventeen faculty members, twenty-seven staff, and graduate students formerly employed by the Rad Lab, occupying the temporary wooden structure of Building 20.[160] MIT's Laboratory for Nuclear Science was founded simultaneously, and both laboratories remained in Building 20 until 1957.[158]

The pattern established at MIT was replicated elsewhere: the Office of Naval Research, drawing on millions of dollars from canceled procurement contracts, became the dominant patron of academic research before the National Science Foundation existed. By August 1946, ONR had issued 177 contracts worth $24 million to eighty-one universities and laboratories.[161]

In 1951, MIT established Lincoln Laboratory to develop air defense systems, building directly on RLE's expertise in radar and digital computing. Located adjacent to Hanscom Air Force Base, which had hosted the Radiation Laboratory's flight tests during the war's final year, Lincoln grew rapidly to a staff of two thousand and an annual budget approaching $20 million.[162] Its first major project, the SAGE air defense network, became the largest military R&D enterprise since the Manhattan Project, eventually costing $8 billion.[163]

The laboratory's technical knowledge was preserved in the MIT Radiation Laboratory Series, a 28-volume compilation edited by Louis Ridenour and published by McGraw-Hill between 1947 and 1953. Rabi had initiated the project in fall 1944, concerned that without systematic documentation "there would only be one group who would know all this technology—the Bell Telephone Laboratories."[164] Some 250 staff members stayed after the war's end to work as authors and editors, and Rabi termed the completed effort "the biggest thing since the Septuagint."[161] The series served as the standard reference for a generation of physicists and engineers. The physicist Louis Brown observed that volumes "would be found on the bookshelves of almost every electronics engineer and experimental physicist for more than a generation."[165]

Organizational influence

The Radiation Laboratory demonstrated what MIT physicist John Slater called the "complementarity of basic and applied research"—the productive integration of physics and electrical engineering that the postwar RLE sought to perpetuate.[166] Slater argued that scientists and engineers working together in an interdisciplinary setting could accomplish far more than either could alone, and that such laboratories should supplement the traditional departmental structure of universities.[167]

The wartime contracting model pioneered by OSRD shaped postwar arrangements. Cost-reimbursement contracts covering direct expenses plus overhead, and the short-form patent clause granting the government title to inventions, became standard features of federal research funding.[168] MIT, as the largest OSRD university contractor at $106.8 million (23.1 percent of all OSRD research spending), was the principal beneficiary of these innovations.[55] By 1946–47, MIT's research budget of $8.3 million dwarfed its academic budget of $4.7 million, a relationship that would persist.[166] Leslie has argued that this "golden triangle" of military agencies, defense industry, and research universities reshaped American science in ways that extended well beyond budgets, channeling research toward military applications at the expense of other priorities.[169]

The laboratory also influenced research style. Buderi characterized the wartime approach as "interdisciplinary, cooperative, hard-driven," and noted that this manner of working shaped postwar academic, industrial, and government laboratories.[161] Rabi and Norman Ramsey drew on their Rad Lab experience when organizing Brookhaven National Laboratory in 1946 as a shared facility for East Coast universities.[161] Two former RLE directors emerged from the Rad Lab, Julius Stratton and Jerome Wiesner, and later became MIT presidents; Wiesner also served as science advisor to President Kennedy.[170]

Technological and regional impact

The Boston area was not an electronics center before the war. The Radiation Laboratory and the smaller Harvard Radio Research Laboratory transformed it into one.[171] Middlesex County experienced what Gross and Sampat describe as a "nearly thirtyfold increase in electronics patenting during the war," with patenting in 1960 remaining ten times prewar levels.[172] The Rad Lab has been widely credited with jump-starting the Route 128 technology corridor by establishing an ecosystem of universities, government laboratories, and firms.[172]

RLE gave rise to fourteen companies in its first two decades, most specializing in microwave electronics and devices.[173] Lincoln Laboratory spawned additional spinoffs. A 1961 Boston bank study suggested replacing the textile spindle with the Hawk missile as the symbol of the local economy.[173]

Commercial applications proliferated. Raytheon, General Electric, and Westinghouse built marine radar and air traffic control systems derived from wartime designs. The SG radar became the basis for postwar navigation systems, and the Microwave Early Warning radar influenced civilian air traffic control.[174] Loran was adopted by commercial shipping and aviation; by war's end the system covered approximately 30 percent of the Earth's surface.[130] Microwave techniques opened roughly two hundred times more radio channels than had previously existed, enabling the postwar expansion of telecommunications.[175]

The laboratory's influence extended through its personnel. Director Lee DuBridge left in 1946 to become president of the California Institute of Technology, a position he held for twenty-three years; he subsequently served as science advisor to Presidents Truman, Eisenhower, and Nixon. Several laboratory members moved between the major wartime research centers: Kenneth Bainbridge and Luis Alvarez, among others, worked at both the Rad Lab and Los Alamos before the war ended.[165] Nine laboratory members later won Nobel Prizes:

At least two Nobel Prizes—for nuclear magnetic resonance and the maser—can be traced directly to wartime radar work.[176] Denis Robinson, who had come from Britain in 1941 to redirect the laboratory toward anti-submarine radar, found after the war that mentioning his Radiation Laboratory experience was "like an 'open sesame' to leading physicists in the United States and Britain."[177]

With the cryptographic work at Bletchley Park and Arlington Hall and the Manhattan Project, the Radiation Laboratory represents what Baxter called one of "the most significant, secret, and outstandingly successful technological efforts" of the Anglo-American wartime alliance.[178] The laboratory was designated an IEEE Milestone in 1990.

See also

Notes

  1. ^ Frank Jewett of Bell Labs proposed locating the laboratory at Bell's Manhattan facilities, citing his organization's experience managing similar research during World War I. However, Bush, Loomis, and Edward Bowles pressed for an academic location.[29]
  2. ^ Though work at MIT began immediately, the contract was not formalized until February 1941.[31]
  3. ^ The Rad Lab's 1,200 technical staff compared to the 1,400 working at Los Alamos.[48]
  4. ^ No source documents the breadth of women's contributions in the Radiation Laboratory. Historian Margaret Rossiter observed that OSRD "grossly underutilized its women scientists" across its projects, frequently relegating qualified scientists to administrative roles, but she does not survey Rad Lab staffing.[53]
  5. ^ Laboratory tradition credited the first echo to the dome of the Christian Science Mother Church.[79]

References

  1. ^ Guerlac 1987.
  2. ^ Buderi 1996, pp. 28–51.
  3. ^ Brown 1999, pp. 42–43.
  4. ^ Brown 1999, p. 82.
  5. ^ Guerlac 1987, pp. 122–174.
  6. ^ Buderi 1996, pp. 36–37.
  7. ^ Guerlac 1987, pp. 59–92.
  8. ^ Guerlac 1987, pp. 93–95.
  9. ^ Guerlac 1987, pp. 96–97.
  10. ^ Brown 1999, pp. 69–70.
  11. ^ Guerlac 1987, pp. 185–188.
  12. ^ Buderi 1996, pp. 83–84.
  13. ^ a b Buderi 1996, p. 88.
  14. ^ Guerlac 1987, pp. 246–247.
  15. ^ a b Baxter 1968, p. 119.
  16. ^ a b c d Guerlac 1987, p. 246.
  17. ^ Stewart 1948, p. 1.
  18. ^ Baxter 1968, p. 9.
  19. ^ Baxter 1968, pp. 141–142.
  20. ^ a b Guerlac 1987, p. 252.
  21. ^ Baxter 1968, p. 141.
  22. ^ Baxter 1968, pp. 119–120.
  23. ^ a b Baxter 1968, p. 120.
  24. ^ a b c Baxter 1968, p. 142.
  25. ^ Buderi 1996, pp. 40–41.
  26. ^ Buderi 1996, p. 43.
  27. ^ Burchard 1948, p. 219.
  28. ^ Baxter 1968, pp. 24–25.
  29. ^ a b Buderi 1996, p. 45.
  30. ^ Burchard 1948, p. 220.
  31. ^ a b Guerlac 1987, p. 259.
  32. ^ Guerlac 1987, p. 261.
  33. ^ a b Buderi 1996, pp. 46–47.
  34. ^ Buderi 1996, p. 47.
  35. ^ a b Guerlac 1987, pp. 260–261.
  36. ^ Buderi 1996, pp. 47–49.
  37. ^ Guerlac 1987, p. 649.
  38. ^ Buderi 1996, pp. 107–108.
  39. ^ Buderi 1996, p. 108.
  40. ^ a b c Buderi 1996, p. 107.
  41. ^ a b Burchard 1948, p. 224.
  42. ^ Buderi 1996, p. 49.
  43. ^ Guerlac 1987, p. 659.
  44. ^ a b Guerlac 1987, p. 700.
  45. ^ Burchard 1948, p. 67.
  46. ^ Buderi 1996, pp. 119–122.
  47. ^ a b Guerlac 1987, p. 668.
  48. ^ a b Geiger 1993, p. 9.
  49. ^ Baxter 1968, p. 22.
  50. ^ Guerlac 1987, pp. 671–672.
  51. ^ a b c Stewart 1948, p. 275.
  52. ^ Guerlac 1987, p. 669.
  53. ^ a b c Rossiter 1995, p. 6.
  54. ^ Coquillette, Elizabeth. "Henrietta Hill Swope". The Harvard Plate Stacks. Harvard University.
  55. ^ a b Stewart 1948, pp. 36, 38.
  56. ^ Baxter 1968, p. 210.
  57. ^ Baxter 1968, pp. 224–225.
  58. ^ Guerlac 1987, pp. 655–656.
  59. ^ Stewart 1948, p. 38.
  60. ^ a b c Stewart 1948, p. 4.
  61. ^ a b Stewart 1948, p. 75.
  62. ^ DuBridge et al. 1946, p. 16.
  63. ^ Guerlac 1987, p. 683.
  64. ^ a b Stewart 1948, p. 67.
  65. ^ Guerlac 1987, p. 655.
  66. ^ a b c Burchard 1948, p. 225.
  67. ^ a b Guerlac 1987, p. 666.
  68. ^ a b Guerlac 1987, p. 661.
  69. ^ Guerlac 1987, pp. 661–662.
  70. ^ a b Guerlac 1987, p. 665.
  71. ^ a b Guerlac 1987, pp. 666–667.
  72. ^ Thomas 2015, p. 77.
  73. ^ Baxter 1968, p. 231.
  74. ^ Guerlac 1987, pp. 749–750, 817.
  75. ^ Guerlac 1987, pp. 819, 870–871.
  76. ^ Baxter 1968, pp. 416–417.
  77. ^ Buderi 1996, pp. 43–44.
  78. ^ Buderi 1996, p. 98.
  79. ^ a b Buderi 1996, p. 101.
  80. ^ Buderi 1996, p. 102–103.
  81. ^ Buderi 1996, p. 102.
  82. ^ a b Guerlac 1987, p. 269.
  83. ^ Buderi 1996, pp. 105–106.
  84. ^ a b Guerlac 1987, p. 282.
  85. ^ a b Guerlac 1987, p. 283.
  86. ^ Brown 1999, p. 170.
  87. ^ Guerlac 1987, pp. 283–284.
  88. ^ a b c d Guerlac 1987, p. 284.
  89. ^ Brown 1999, p. 171.
  90. ^ DuBridge et al. 1946, p. 45.
  91. ^ a b Buderi 1996, p. 121–122.
  92. ^ Buderi 1996, p. 122.
  93. ^ a b Buderi 1996, p. 125.
  94. ^ Buderi 1996, p. 115.
  95. ^ a b c d Baxter 1968, p. 147.
  96. ^ Buderi 1996, p. 139.
  97. ^ a b Burchard 1948, p. 229.
  98. ^ a b Guerlac 1987, p. 288.
  99. ^ a b Guerlac 1987, p. 289.
  100. ^ a b Guerlac 1987, p. 293.
  101. ^ a b Guerlac 1987, p. 294.
  102. ^ Guerlac 1987, p. 295.
  103. ^ Guerlac 1987, pp. 525–526.
  104. ^ DuBridge et al. 1946, p. 49.
  105. ^ Guerlac 1987, p. 530.
  106. ^ a b DuBridge et al. 1946, p. 50.
  107. ^ a b c Brown 1999, p. 431.
  108. ^ Guerlac 1987, p. 485.
  109. ^ Buderi 1996, p. 135.
  110. ^ a b c d Brown 1999, p. 194.
  111. ^ Guerlac 1987, p. 494.
  112. ^ Brown 1999, p. 195.
  113. ^ Guerlac 1987, p. 449.
  114. ^ a b c Brown 1999, p. 196.
  115. ^ Buderi 1996, pp. 136–137.
  116. ^ Brown 1999, p. 392.
  117. ^ DeBridge et al. 1946, p. 66. sfn error: no target: CITEREFDeBridgeGuerlacJohnsonHalpern1946 (help)
  118. ^ Buderi 1996, p. 225.
  119. ^ Buderi 1996, p. 220.
  120. ^ a b c Brown 1999, p. 197.
  121. ^ Baxter 1968, pp. 87–88.
  122. ^ Guerlac 1987, p. 537.
  123. ^ a b c Guerlac 1987, p. 538.
  124. ^ a b Buderi 1996, p. 365.
  125. ^ Loomis 1946, p. 91. sfn error: no target: CITEREFLoomis1946 (help)
  126. ^ Guerlac 1987, p. 544.
  127. ^ Guerlac 1987, p. 545.
  128. ^ Buderi 1996, p. 157.
  129. ^ Baxter 1968, p. 44.
  130. ^ a b Conant 2002, pp. 265–267.
  131. ^ a b Buderi 1996, p. 167.
  132. ^ Buderi 1996, p. 170.
  133. ^ a b c Craven & Cate 1951, p. 13.
  134. ^ a b c Buderi 1996, p. 212.
  135. ^ Baxter 1968, p. 95–96.
  136. ^ Craven & Cate 1951, p. 15.
  137. ^ a b Craven & Cate 1951, p. 16.
  138. ^ a b Buderi 1996, p. 213.
  139. ^ Craven & Cate 1951, p. 280.
  140. ^ Guerlac 1987, p. 1094.
  141. ^ Craven & Cate 1951, p. 296.
  142. ^ Craven & Cate 1951, p. 641.
  143. ^ Guerlac 1987, p. 393.
  144. ^ Buderi 1996, p. 243.
  145. ^ a b c Buderi 1996, p. 109.
  146. ^ Guerlac 1987, p. 853.
  147. ^ Buderi 1996, p. 111.
  148. ^ Buderi 1996, p. 112.
  149. ^ Baxter 1968, p. 147–148.
  150. ^ Buderi 1996, p. 134.
  151. ^ a b Buderi 1996, p. 221.
  152. ^ Conant 2002, p. 271–272.
  153. ^ Buderi 1996, p. 223.
  154. ^ Brown 1999, pp. 399–400.
  155. ^ Guerlac 1987, p. 856–857.
  156. ^ Guerlac 1987, p. 856.
  157. ^ Guerlac 1987, p. 442.
  158. ^ a b Buderi 1996, p. 255.
  159. ^ Geiger 1993, p. 33.
  160. ^ Leslie 1993, p. 26.
  161. ^ a b c d Buderi 1996, p. 251.
  162. ^ Leslie 1993, pp. 34–35.
  163. ^ Leslie 1993, p. 35.
  164. ^ Buderi 1996, p. 250.
  165. ^ a b Brown 1999, p. 174.
  166. ^ a b Geiger 1993, p. 64.
  167. ^ Geiger 1993, p. 30.
  168. ^ Baxter 1968, pp. 210, 224–225.
  169. ^ Leslie 1993, pp. 6–7.
  170. ^ Buderi 1996, pp. 129, 255.
  171. ^ Gross & Sampat 2023, p. 3331.
  172. ^ a b Gross & Sampat 2023, p. 3333.
  173. ^ a b Leslie 1993, p. 32.
  174. ^ Buderi 1996, pp. 16, 220.
  175. ^ Buderi 1996, p. 16.
  176. ^ Buderi 1996, p. 15.
  177. ^ Buderi 1996, p. 254.
  178. ^ Baxter 1968, p. 456.

Bibliography

NDRC Summary Technical Reports
  • DuBridge, Lee A.; Guerlac, Henry E.; Johnson, M. H.; Halpern, O. (1946). Radar: Summary Report and Harp Project (PDF) (Report). Vol. 1. Washington DC: Office of Scientific Research and Development.
  • Thrall, Robert M., ed. (1946). Military Airborne Radar Systems (PDF) (Report). Vol. 2. Washington DC: Office of Scientific Research and Development.
  • Bibliography of Division 14 and Radiation Laboratory Reports (PDF) (Report). Vol. 3. Washington DC: Office of Scientific Research and Development. 1946.
Official histories
  • Baxter, James Phinney III (1968) [1946]. Scientists Against Time. Cambridge, MA: MIT Press.
  • Guerlac, Henry E. (1987) [1946]. Radar in World War II. Tomash/American Institute of Physics.. 2 volumes. Vol 2
  • Newton, Charles; Petersen, Thelma E.; Perkins, Nancy Joy, eds. (1946). Five Years at the Rad Lab. Andover, MA: Andover Press.
  • Stewart, Irvin (1948). Organizing Scientific Research for War; Administrative History of the OSRD. Boston: Little, Brown & Co.
General histories
  • Brown, Louis (1999). A Radar History of World War II: Technical and Military Imperatives. Bristol, UK: Institute of Physics. ISBN 9780750306591.
  • Buderi, Robert (1996). The Invention that Changed the World: How a Small Group of Radar Pioneers Won the Second World War and Launched a Technological Revolution. Simon & Schuster. ISBN 978-0684835297.
  • Burchard, John Ely (1948). Q.E.D.: MIT in World War II. New York: J. Wiley & Sons; Chapman & Hall. OCLC 1625883.
  • Conant, Jennet (2002). Tuxedo Park. New York, NY: Simon & Schuster. ISBN 0-684-87287-0.
  • Craven, Wesley Frank; Cate, James Lea (1951). The Army Air Forces in World War II, Volume Three: Europe: Argument to V-E Day, January 1944 to May 1945. Chicago: University of Chicago Press. OCLC 256469807.
  • Geiger, Roger L. (1993). Research and Relevant Knowledge : American Research Universities since World War II. New York; London: Oxford University Press.
  • Leslie, Stuart W. (1993). The Cold War and American Science: The Military-Industrial-Academic Complex at MIT and Stanford. New York: Columbia University Press. ISBN 9780231079587.
  • Rossiter, Margaret (1995). Women Scientists in America : Before Affirmative Action, 1940-1972. Baltimore: Johns Hopkins University Press.
  • Thomas, William (2015). Rational Action: The Sciences of Policy in Britain and America, 1940–1960. Cambridge, MA: MIT Press. doi:10.7551/mitpress/9997.001.0001. ISBN 978-0-262-02850-9.
  • Zimmerman, David (1996). Top Secret Exchange: the Tizard Mission and the Scientific War. Montreal: McGill-Queen's Univ. Press.
Studies
  • Gross, Daniel P.; Sampat, Bhaven N. (2023). "America, Jump-Started: World War II R&D and the Takeoff of the U.S. Innovation System". American Economic Review. 113 (12): 3323–3356. doi:10.1257/aer.20221365.

Further reading

Participant accounts

  • Bowen, Edward G. (1987). Radar Days. Inst. of Physics Publishing.
  • Getting, Ivan (Oct 1990). "SCR-584 Radar and The Mark 56 Naval Gun Fire Control System" (PDF). IEEE Aerospace and Electronic Systems Magazine. 5 (10): 3–15. doi:10.1109/62.60673.
  • Ridenour, Louis (May 1946). "Radar in War and Peace". Electrical Engineering. Vol. 65, no. 5. doi:10.1109/EE.1946.6441669.

Other

  • Fine, Norman (2019). Blind Bombing: How Microwave Radar brought the Allies to D-Day and Victory in World War II. Nebraska: Potomac Books/University of Nebraska Press. ISBN 978-1640-12279-6.
  • Page, Robert Moris (1962). The Origin of Radar. Anchor Books.
  • Willoughy, Malcom Francis (1980). The Story of LORAN in the U.S. Coast Guard in World War II. Arno Pro.
  • Echoes of War (1989), WGBH documentary on the Rad Lab
  • MIT Archives: Celebrating the History of Building 20
  • Research Laboratory of Electronics History
  • IEEE Global History Network - MIT Rad lab Oral History Collection
  • MIT Radiation Laboratory Series (28 volumes)


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