Defense Advanced Research Projects AgencyAbout UsHistory and Timeline

Where the Future Becomes Now

The Defense Advanced Research Projects Agency was created with a national sense of urgency in February 1958 amidst one of the most dramatic moments in the history of the Cold War and the already-accelerating pace of technology. In the months preceding the official authorization for the agency’s creation, Department of Defense Directive Number 5105.15, the Soviet Union had launched an Intercontinental Ballistic Missile (ICBM), the world’s first satellite, Sputnik 1, and the world’s second satellite, Sputnik II… More

Launch of first satellite ever by USSR, sparks creation of DARPA
On October 4, 1957, the Soviet Union (USSR) launched the first satellite ever, triggering events that led to creation of the Advanced Research Projects Agency (ARPA) on February 7, 1958. Although it was well known that both the USSR and the United States were working on satellites for the international scientific collaboration known as the International Geophysical Year (an 18-month “year” from July 1, 1957, to December 31, 1958 and designed to coincide with a peak phase of the solar cycle), many in the United States never fathomed that the USSR would be the first into space. “Now, somehow, in some way, the sky seemed almost alien,” then-Senate Majority Leader Lyndon B. Johnson recalled feeling on that night, adding that he remembered “the profound shock of realizing that it might be possible for another nation to achieve technological superiority over this great country of ours.” Ever since its establishment on February 7, 1958, ARPA—which later added the D for defense at the front of its name—has been striving to keep that technological superiority in the hands of the United States.
| History | Space |
DoD Directive Establishes the Advanced Research Projects Agency
On February 7, 1958, Neil McElroy, the Department of Defense Secretary, issued DoD Directive 5105.15 establishing the Advanced Research Projects Agency (ARPA), later renamed the Defense Advanced Research Projects Agency (DARPA). The Agency’s first three primary research thrusts focused on space technology, ballistic missile defense, and solid propellants
Saturn V and Centaur Rockets

In its first months, ARPA managed and funded rocket development programs that would prove to be long-lived and far-reaching. Among these was a launch-vehicle program under the auspices of Wernher von Braun’s engineering team that would transfer to America’s new civilian space program, the National Aeronautics and Space Administration (NASA). There, von Braun’s initial booster technology, Juno V, would lead to the cluster-engine Saturn V Space Launch Vehicle, famous for its role in manned spaceflight to the Moon.

Another DARPA-authorized program in 1958, development of a liquid oxygen/hydrogen (LOX/LH2) upper-stage rocket known as Centaur, also transferred to the fledgling NASA. After several failures, the Centaur booster achieved its first successful orbital flight in 1963 and its first successful mission in 1966. Centaur rockets improved the ability of U.S. launch vehicles to place sizeable payloads into geosynchronous Earth orbit (GEO) and helped pave the way toward future lunar and deep space missions. During its evolution, the Centaur LOX/LH2 upper stage technology has been used extensively on Atlas and Titan boosters for diverse missions. Centaur engine technology was also used in the upper stages of the Saturn rockets for the Apollo manned missions to the Moon and in the Space Shuttle’s liquid hydrogen-oxygen engines.

First Weather Satellite: Television and Infrared Observations Satellites (TIROS)

Initiated by ARPA in 1958 and transferred to NASA in 1959, the Television and Infrared Observations Satellites (TIROS) program became the prototype for the current global systems used for weather reporting, forecasting and research by the Defense Department, NASA and the National Oceanographic and Atmospheric Administration (NOAA). Moreover, TIROS helped define ARPA’s model of successfully bringing together scientists and engineers from different services, federal agencies, and contracting firms to solve vexing problems and quickly achieve a complex technical feat.

The program greatly advanced the science of meteorology by placing the first dedicated weather satellite in orbit, TIROS 1, on April 1, 1960. The mission swiftly proved the viability of observing weather from space. It took 23,000 cloud-cover pictures, of which more than 19,000 were used in weather analysis. For the first time, meteorologists were able to track storms over the course of several days.

Solid state phased array radar system circa 1959.

Before DARPA was established, a President’s Science Advisory Committee panel and other experts had concluded that reliable ballistic missile defense (BMD) and space surveillance technologies would require the ability to detect, track, and identify a large number of objects moving at very high speeds. Responding to these needs, DARPA in 1959 initiated a competition for the design and construction of a large, experimental two-dimensional phased array with beam steering under computer control rather than requiring mechanical motion of the antenna.

Known as the Electronically Steered Array Radar (ESAR) Program, the focus of the effort was to develop low-cost, high-power tubes and phase shifters, extend component frequency ranges, increase bandwidth, apply digital techniques, and study antenna coupling. DARPA pioneered the construction of ground-based phased array radars such as the FPS-85. This radar system had a range of several thousand miles and could detect, track, identify, and catalog Earth-orbiting objects and ballistic missiles. The FPS-85 quickly became part of the Air Force SPACETRACK system and was in operation from 1962 until the SPACETRACK unit was deactivated in early 1967.

Corona Reconnaissance Satellite
One of the world’s earliest and most well-known spy satellite programs, the now declassified Corona photo-reconnaissance program was jointly funded by DARPA and the Central Intelligence Agency. Withstanding a series of initial failures, the program scored its first success in August 1960 when a canister of film dropped back through the atmosphere was successfully recovered, delivering a trove of intelligence photos taken over Soviet territory. The Corona program continued to acquire crucial Cold War intelligence until the mission ended in 1972.
Interdisciplinary Laboratories and Materials Science
In 1960, ARPA helped establish what now is the burgeoning field of materials science and engineering by announcing the first three contracts of the Agency’s Interdisciplinary Laboratory (IDL) program. Following these initial four-year renewable contracts to Cornell University, the University of Pennsylvania, and Northwestern University, the Agency awarded nine more IDL contracts around the country. The program lasted just over a decade when, in 1972, the National Science Foundation (NSF) took over the program and changed its name to the Materials Research Laboratories (MRL) program.
Transit Satellite: Precursor to Global Positioning System

ARPA launched the first satellite in what would become the world's first global satellite navigation system. Known as Transit, the system provided accurate, all-weather navigation to both military and commercial vessels, including most importantly the U.S. Navy’s ballistic missile submarine force.

Transit, whose concept and technology were developed by Johns Hopkins University Applied Physics Laboratory, established the basis for wide acceptance of satellite navigation systems. The system's surveying capabilities—generally accurate to tens of meters—contributed to improving the accuracy of maps of the Earth's land areas by nearly two orders of magnitude.

ARPA funded the Transit program in 1958, launched its first satellite in 1960, and transitioned the technology to the Navy in the mid-1960s. By 1968, a fully operational constellation of 36 satellites was in place. Transit operated for 28 years until 1996, when the Defense Department replaced it with the current Global Positioning System (GPS).

ARPA Midcourse Optical Station

The Agency initiated the ARPA Midcourse Optical Station (AMOS) program in 1961 with the goal of developing an astronomical-quality observatory to obtain precise measurements and images of satellites, payloads, and other space objects re-entering the atmosphere from space. ARPA located the facility atop Mount Haleakala, Maui, Hawaii, nearly 10,000 feet above sea level.

By 1969, the quality and potential of AMOS had been demonstrated, and a second phase began to measure properties of re-entry bodies at the facility under the Advanced Ballistic Reentry System Project. In the late 1970s, successful space object measurements continued in the infrared and visible ranges, and laser illumination and ranging were initiated.

Other developments such as the compensated imaging program were tested successfully at AMOS. By 1984, the AMOS twin infrared telescopes had become a highly automated system and DARPA transferred it to the U.S. Air Force as one of the primary sensors of the Air Force Space Tracking System. In 1993, the Air Force renamed AMOS as the Air Force Maui Optical and Supercomputing Site.

Project Agile
In what ended up being for the Agency an extremely rare practice of direct or near-direct support of active military operations, ARPA initiated Project Agile in 1961, which grew into a large and diverse portfolio of counterinsurgency research programs in Southeast Asia. The project ran through 1974. Along the way, subprojects included weapons (among them flamethrowers and what became known as the M-16 assault rifle), rations, mobility and logistics in remote areas, communications, surveillance and target acquisition, defoliation, and psychological warfare.

DARPA’s Information Processing Techniques Office (IPTO) was born in 1962 and for nearly 50 years was responsible for DARPA’s information technology programs. IPTO invested in breakthrough technologies and seminal research projects that led to pathbreaking developments in computer hardware and software. Some of the most fundamental advances came in the areas of time-sharing, computer graphics, networking, advanced microprocessor design, parallel processing and artificial intelligence.

IPTO pursued an investment strategy in line with the vision of the office’s first director, J. C. R. Licklider. Licklider believed that humans would one day interact seamlessly with computers, which, in his words, “were not just superfast calculating machines, but joyful machines: tools that will serve as new media of expression, inspirations to creativity, and gateways to a vast world of online information." IPTO was combined with DARPA’s Transformational Convergence Technology Office (TCTO) in 2010 to form the Information Innovation Office (I2O).

oN-Line System
A groundbreaking computer framework known as oN-Line System (NLS) got off the ground thanks to funding from DARPA and the U.S. Air Force. Conceived by Douglas Engelbart and developed by him and colleagues at the Stanford Research Institute (SRI), the NLS system was the first to feature hypertext links, a mouse, raster-scan video monitors, information organized by relevance, screen windowing, presentation programs and other modern computing concepts. In what became known as "The Mother of All Demos," because it demonstrated the revolutionary features of NLS as well as never-before-seen video presentation technologies, Engelbart unveiled NLS in San Francisco on December 9, 1968, to a large audience at the Fall Joint Computer Conference. Engelbart's terminal was linked to a large-format video projection system loaned by the NASA Ames Research Center and via telephone lines to a SDS 940 computer (designed specifically for time-sharing among multiple users) 30 miles away in Menlo Park, California, at the Augmentation Research Center, which Engelbart founded at SRI. On a 22-foot-high screen with video insets, the audience could see Engelbart manipulate the mouse and watch as members of his team in Menlo Park joined in the presentation. With the arrival of the ARPA Network at SRI in 1969, the time-sharing technology that seemed practical with a small number of users became impractical over a distributed network, but NLS opened pathways toward today’s astounding range of information technologies.
Arecibo Observatory

On November 6, 1959, Cornell University signed a contract with ARPA to conduct development studies for a large-scale ionospheric radar probe and how such an instrument might also serve in radioastronomy and other scientific fields. Four years later, on November 1, 1963, an inauguration ceremony was held in Arecibo, Puerto Rico, for the Arecibo Ionospheric Observatory, later to be known more generally as the Arecibo Observatory.

Its telescope "dish"—the largest in the world until 2016 with the completion in China of the FAST dish telescope—is 1,000 feet (305 meters) in diameter,  167 feet (51 meters) deep, and covers an area of approximately 20 acres (0.08 square kilometers). Development of the Arecibo facility was initially supported as part of the DEFENDER program, a broad-based missile defense program. The observatory was designed to study the structure of the upper ionosphere and its interactions with electromagnetic communications signals.

The observatory now is part of the National Astronomy and Ionosphere Center (NAIC), a national research center operated by SRI International, the Universities Space Research Association (USRA), and Universidad Metropolitana (UMET) through a cooperative agreement with the National Science Foundation (NSF). Researchers have tapped the observatory for their studies of ionospheric physics, radar and radio astronomy, aeronomy, and dynamics of the Earth’s upper atmosphere. The facility also helped NASA select lunar landing sites as well as landing sites for the Viking missions to Mars. The observatory remains in use today.


The ARPA Vela program developed sensors to detect nuclear explosions in space, the upper atmosphere, and underwater to support the 1963 Limited Nuclear Test Ban Treaty, under which the United States, Great Britain, and the Soviet Union banned atmospheric tests of nuclear weapons. The first VELA sensors, deployed on a pair of satellites launched three days after the treaty was signed, were designed to monitor for optical and electromagnetic signatures of nuclear explosions in the atmosphere.

Later in the 1960s and 1970s, DARPA oversaw the development of the World Wide Standardized Seismograph Network (WWSSN) for detecting underground nuclear tests. The Agency also helped expand detection technologies globally and internationally by running workshops, funding research projects in other countries, and championing community-building initiatives.


As part of an ARPA-funded experiment to find better ways for computer users to interact with computers, Douglas Engelbart of SRI—who would later work on the DARPA-sponsored ARPANET project, the Internet’s precursor—invented the computer mouse. The first mouse was carved out of wood and had just one button. Later incarnations such as this early Logitech® mouse led to the diversity of mice now on desktops around the world.

The mouse was an early example of many innovations that DARPA would help nurture into various components of the information technology landscape over the next five decades. In What Will Be (HarperCollins, 1997), author Michael Dertouzos credits DARPA with “… between a third and a half of all the major innovations in computer science and technology.”

Project Mac
One of the first major efforts supported by ARPA's Information Processing Techniques Office (IPTO) was the Project on Mathematics and Computation (Project MAC), the world’s first large-scale experiment in personal computing, at the Massachusetts Institute of Technology (MIT). Orchestrated within the general context of broad-based command and control research suggested by the Office of the Secretary of Defense, and based on the vision of the founding IPTO Director, J.C.R. Licklider, Project MAC was oriented toward achieving a new level of human-computer interaction.
M16 - National Archives Image

The M16 Assault Rifle is the standard-issue shoulder weapon in the U.S. military. Designed to fire small, high-velocity rounds (5.56 mm caliber vs. 7.62 mm), the weapon is relatively small and light, thereby significantly decreasing the overall load warfighters needed to carry.

The M16 is based on a design (the Colt AR-15) that had already been rejected by the Chief of Staff of the Army in favor of the heavier 7.62 mm M14. Colt brought the weapon to DARPA in 1962.

Through Project AGILE, DARPA purchased 1,000 AR-15s and issued them to combat troops in Southeast Asia for field trials, to prove that the high-velocity 5.56 mm round had satisfactory performance. The subsequent DARPA report documenting the lethality of the AR-15 was instrumental in motivating the Secretary of Defense to reconsider the Army’s decision and this led to a the first large-scale procurement in 1966 of a modified AR-15—the M16—for deployment in the Vietnam conflict.

Shakey the Robot
Charles Rosen, head of the Machine Learning Group at the Stanford Research Institute (now known as SRI International) developed a proposal in 1964 to build a robot that at the time would have featured the intelligence and capabilities that had only been depicted in science fiction books and movies. Even then, Rosen knew that ARPA might appreciate the potential and provide support, which the Agency did in 1966. Six years later, Rosen’s team literally rolled out Shakey, so-named because it shook as it moved. More importantly, Shakey was the first mobile robot with enough artificial intelligence to navigate on its own through a set of rooms. Among its component technologies were a TV camera, a range finder, radio communications, and a set of drive wheels controlled with stepping motors.
PreStealth Stealth—the QT-2 quiet aircraft
The efficacy of nighttime aerial reconnaissance operations in Southeast Asia was diminished due to engine noise that provided the enemy with advanced warning of approaching aircraft. With an eye on making quiet aircraft that could better serve this reconnaissance mission, ARPA funded the Lockheed Missile and Space Company to develop a quiet, propeller-driven aircraft. This fast-paced program quickly yielded a successful prototype, the QT-2, which in 1968 was deployed and proven in combat. The program transitioned to the U.S. Army, which sponsored a limited production of an advanced version of the quiet aircraft, the YO-3A.
| Air | History |
Explosive Forming
Between 1968 and 1972, ARPA supported an effort proposed by the University of Denver to use explosives for forming metal parts for aerospace applications. The underwater process relied on a mold for the part over which was placed a plate of the metal alloy to be used. This preparation, when immersed in water, would feel the shock of an explosive charge to such a degree that the metal plate would be forced against the die. The process could reproducibly deliver serviceable parts out of steel, aluminum, titanium, and Inconel, a superalloy. The effort opened a new way to produce a variety made of aerospace components, including engine parts such as engine diffusers and afterburner rings for Pratt &Whitney engines that powered the storied SR71. The variation of the process also was deployed for many years to weld superstructures to the decks of U.S. Navy warships.
The Mother of all Demos

Conceived by Douglas Engelbart and developed by him and colleagues at the Stanford Research Institute (SRI), the groundbreaking computer framework known as oN-Line System (NLS), jointly funded by ARPA and the Air Force, evolved throughout the decade. In what became known as "The Mother of All Demos"—because it demonstrated the revolutionary features of NLS as well as never-before-seen video presentation technologies—Engelbart unveiled NLS in San Francisco on December 9, 1968, to a large audience at the Fall Joint Computer Conference. Engelbart's terminal was linked to a large-format video projection system loaned by the NASA Ames Research Center and via telephone lines to a SDS 940 computer (designed specifically for time-sharing among multiple users) 30 miles away in Menlo Park, California, at the Augmentation Research Center, which Engelbart founded at SRI. On a 22-foot-high screen with video insets, the audience could see Engelbart manipulate the mouse and watch as members of his team in Menlo Park joined in the presentation.

With the arrival of the ARPA Network at SRI in 1969, the time-sharing technology that seemed practical with a small number of users became impractical over a distributed network. NLS, however, opened pathways toward today’s astounding range of information technologies.

ARPANET and the Origins of the Internet
ARPA research played a central role in launching the “Information Revolution,” including developing or furthering much of the conceptual basis for ARPANET, a pioneering network for sharing digital resources among geographically separated computers. Its initial demonstration in 1969 led to the Internet, whose world-changing consequences unfold on a daily basis today. A seminal step in this sequence took place in 1968 when ARPA contracted BBN Technologies to build the first routers, which one year later enabled ARPANET to become operational.
Compact Turbofan Engines

Building on the momentum of jet engine research prior to ARPA’s creation, the Agency joined with the U.S. Army in 1965 on the Individual Mobility System (IMS) project (1965-1969) with the goal of extending the range and endurance of the Bell Rocket Belt developed for the Army in the 1950s. With DARPA funding, Bell replaced the vertical lift rocket system with a compact, highly efficient turbofan engine that Williams Research Corporation was developing.

The DARPA project helped bring the WR-19 turbofan engine into full development. It also brought it to the attention of the U.S. Air Force, for which the engine demonstrated excellent horizontal flight characteristics. The engine was adapted for use in the new Air Force cruise missile program. The U.S. Navy also became interested in the Williams Research engines as it adapted cruise missiles for maritime applications.

By the 1990s, improved versions of the Williams engine would power all the air, surface, and subsurface launched cruise missiles in the Navy and Air Force inventories. Later incarnation of these propulsion technology developments would power the AGM-86B air-launched cruise missiles and Navy Tomahawk cruise missiles in Desert Storm in 1991 and in subsequent conflicts.

Torpedo Propulsion

In 1969, the Applied Research Laboratory at Penn State began work, under U.S. Navy sponsorship, on a lithium-based thermal energy system for torpedo application. The system, known as the Stored Chemical Energy Propulsion System (SCEPS), was applicable to the high-power, short-duration mission of a torpedo. In a subsequent effort to further torpedo capabilities, DARPA subsequently selected the SCEPS heat source for use with an engine design that could be suitable for deployment in a long-endurance undersea vehicle.

One of the engineering obstacles that the DARPA adaptation of the heat source overcame was the development of long-life injectors of SF6 (one of the SCEPS chemical ingredients) that could survive in the system’s molten lithium bath. The Navy SCEPS program, which had also been experiencing some difficulty with injectors, adapted the DARPA technology. SCEPS became the power plant for the MK 50 Torpedo, which the Navy first authorized for use in late 1992.

Beryllium Mirror Research

From 1968 to 1972, ARPA funded a program with the Perkin Elmer Corporation to develop the technology for fabricating large, stable, low-weight mirrors from beryllium, a featherweight metal, for use in space applications. The early focus of the program was in developing and evaluating improved forms of beryllium. Perkin Elmer was successful in improving the thermal stability of beryllium surfaces tenfold, and developing materials-processing techniques (powder metallurgy, hot isostatic processing, pressureless sintering) for making it possible to fabricate large beryllium structures.

Further ARPA- funded efforts led to surface-polishing techniques to dramatically reduce scattering of infrared wavelengths, the successful development of thin-film coatings techniques, and a demonstration of the long-term stability of beryllium surfaces. DoD applications included 1) the all-beryllium, 15-inch aperture, long-wave infrared (IR) telescope system for the Midcourse Airborne Target Signature program run by what was then known as the Advanced Ballistic Missile Defense Agency; 2) the fabrication of a lightweight, 40-inch, aspheric mirror for the U.S. Air Force; and 3) experimental near-net-shape production of a key component of the Trident 11 MK6 guidance system. NASA also applied the technology in the form of a 85-cm beryllium mirror assembly for NASA Jet Propulsion Laboratory (JPL)'s IR Telescope Technology Testbed for eventual use in NASA's Space Infrared Telescope Facility (later renamed the Spitzer Space Telescope), which was launched in 2003 and as of 2018 was still in operation.

Camp Sentinel Radar

The Camp Sentinel Radar penetrated foliage to detect infiltrators near U.S. deployments and was a fast turnaround,Vietnam-era development of advanced technology. Camp Sentinel responded to a military need for intruder detection with enough accuracy to direct fire. DARPA recommended a foliage penetration radar, which was completed within two years at a direct cost of $2 million. Camp Sentinel radar prototypes were field-tested in Vietnam in 1968 and retained by the troops for use for the rest of the war.

The Camp Sentinel technology pioneered the development of radar in hostile jungle conditions, which feature absorption and refraction by foliage in high-clutter environments, among other challenges. The Camp Sentinel radar project developed clutter rejection processing techniques, which were also later used by commercial acoustic-based intruder detectors.

| History | ISR |
Anti-Submarine Warfare

With the blue water threat of free-ranging, nuclear-armed Soviet submarines coming to a head in 1971, the Department of Defense (DoD) assigned DARPA a singular mission: Revamp the U.S. military’s anti-submarine warfare (ASW) capabilities to track enemy subs under the open ocean where the U.S. Navy’s existing Sound Surveillance System (SOSUS) was falling short. At the time, the U.S. Navy was already working on what would become its Surveillance Towed Array Sensor System, or SURTASS, through which surface ships towed long, mobile arrays of sensors to listen for submarine activity. Telemetry and data-handling issues greatly limited the system’s capabilities.

That’s when DARPA committed funds for the LAMBDA program to modify oil-industry-designed seismic towed arrays so they could detect submarine movement. DARPA-funded scientists began experiments at submarine depths, and soon generated spectacular results. In 1981, the DoD gave quick approval for production of a LAMBDA-enhanced SURTASS array, without requiring further study, a highly unusual decision for a program that had experienced a major technology shift late in the game. The system—which with DARPA participation would become enhanced by way of leading-edge computational tools, satellite-based data linkages, and computer networking—would become the Navy’s go-to method for tracking mobile Soviet subs for the remainder of the Cold War. By 1985, Secretary of the Navy John Lehman was so confident in his force’s ability to keep tabs on elusive Soviet boomers (a nickname for ballistic missile submarines), he declared that in the event the Cold War turned hot, he would attack Soviet subs “in the first five minutes of the war.”

Glassy Carbon

From 1971 to 1974, ARPA supported research on "glassy" carbon, a unique foam material composed of pure carbon and that combined low weight, high strength, and chemical inertness. The program led to techniques for producing the material with an exceptionally porous, high surface area combined with high rigidity, low resistance to fluid flow, and resistance to very high temperatures in a non-oxidizing environment.

Eyed originally for roles in electro-chemistry because of its high surface area, the material proved suitable for surgical implants, especially heart valves. Development of the valves began about three years after the end of the ARPA program, with production commencing in 1985. In 1990, the U.S. Food and Drug Administration (FDA) gave its approval for using glassy carbon in implants in a valve market that grew within the decade to 100,000 units and a market value of $200 million. A related form, pyrolytic carbon, remains common in the inner orifice and leaflets of artificial valves.

Rare-Earth Magnets
New materials that perform better than previous ones or with unprecedented properties open pathways to new and improved technologies. F-15 and F-16 fighter aircraft, still in use by the U.S. Air Force today, owe much of their performance advancements to materials technologies that emerged from DARPA materials development programs conducted in the 1970s and early 1980s. One of many notable successes from these efforts was the development of rare-earth permanent magnets with magnetic strengths far stronger than conventional magnetic materials and, in some cases, over larger operational conditions. The samarium- and cobalt-based rare-earth magnetic material Sm2Co17, for example, remains reliable over the entire militarily relevant temperature range of -55°C to 125°C. These magnets ultimately assumed a role in a key component of the AN/ALQ-135 electronic warfare system, permitting operation of the F-15 to 70,000 feet in altitude.
ARPA Changes Names
The Advanced Research Projects Agency (ARPA) gained a “D” when it was renamed the Defense Advanced Research Projects Agency (DARPA) in 1972. The Agency’s name briefly reverted to ARPA in 1993, only to have the “D” restored in 1996.
Gallium Arsenide
Beginning in the mid-1970s, DARPA orchestrated extensive research into the semiconductor material gallium arsenide, which could host faster transistors operating at higher power than could silicon. The work would contribute to subsequent DARPA-spurred achievement in the 1980s to miniaturize receivers for GPS. That technology, in conjunction with DARPA-developed advances in inertial navigation, expanded the Nation’s arsenal of precision-guided munitions (PGMs) through such innovations as “bolt-on” Joint Direct Attack Munitions (JDAM) GPS kits, which gave otherwise unguided or laser-guided munitions new, high-precision capabilities. Key to these developments were gallium arsenide chips developed through DARPA’s Monolithic Microwave Integrated Circuit program, which also enabled the radio frequency (RF) and millimeter-wave circuits needed in precision weapons.
TCP-IP - IEEE Image 1974
In a seminal moment in the development of the Internet, DARPA’s Robert Kahn (who joined the Information Processing Techniques Office as a program manager in 1972) asked Vinton Cerf of Stanford University to collaborate on a project to develop new communications protocols for sending packets of data across the ARPANET. That query resulted in the creation of the Transmission Control Protocol (TCP) and the Internet Protocol (IP), most often seen together as TCP/IP. These protocols remain a mainstay of the Internet’s underlying technical foundation.
Ceramic Turbine: Brittle Materials Design

ARPA began a program to demonstrate and encourage the use of brittle high-temperature materials in engineering design, with an eye on ceramic components for gas turbine applications. The approach included major efforts in ceramic design, materials development, fabrication process development, and test and evaluation methodology. By the end of the program in 1979, one of the performers, a team with Ford, demonstrated that design with brittle materials in highly stressed applications is possible and, in particular, that ceramics are feasible as major structural components in gas turbine engines. This program started the "Ceramic Fever" that spread throughout the world in the late 1970s and early 1980s.

The successful demonstration of ceramics in a gas turbine environment led to the establishment of ceramic programs in virtually every automotive or engine company in the world, in other U.S. government agencies, and in several foreign countries.

HAVE BLUE and the Origin of Stealth Technology

In the early 1970s, a DARPA study brought to light the extent of vulnerabilities of U.S. aircraft and their on-board equipment to detection and attack by adversaries, who were deploying new advanced air-defense missile systems. These systems integrated radar-guided surface-to-air missiles (SAMs) and air-launched radar-guided missiles, all networked with early-warning, acquisition, and targeting radars, and coordinated within sophisticated command and control frameworks.

To mitigate these growing threats, DARPA embarked on a program to develop strategies and technologies for reducing radar detectability, including the reduction of radar cross section through a combination of shaping (to minimize the number of radar return spikes) and radar absorbent materials; infrared shielding, exhaust cooling and shaping, and enhanced heat dissipation; reduced visual signatures; active signature cancellation; inlet shielding; and windshield coatings.

In the mid-1970s, DARPA oversaw the development of HAVE Blue, the first practical combat stealth aircraft, which made its first test flight by the end of 1977. This led to the procurement by the Air Force of the F-117A stealth fighter, which became operational in October 1983. A follow-on development, the TACIT Blue aircraft, could operate radar sensors while maintaining its own low radar cross-section. This laid foundations for development of the B-2 stealth bomber.

Stealth aircraft destroyed key targets in conflicts in Iraq, both in the 1991 Desert Storm operation and in 2003 during Operation Iraqi Freedom; in Afghanistan during Operation Enduring Freedom in 2001; and in Libya in 2011. Complementing the key contributions of stealth capabilities in these missions was Department of Defense’s use of other technologies, including DARPA-enabled precision-guided munitions, which were deployed by stealth and non-stealth aircraft. Since their initial development and deployment, stealth technologies have been applied to a wide range of weapon systems and military platforms, among them missiles, helicopters, ground vehicles and ships.

Assault Breaker
In 1978, DARPA integrated a number of technologies—including lasers, electro-optical sensors, microelectronics, data processors, and radars—important for precision guided munitions (PGMs) under its Assault Breaker program. Over a four-year period, Assault Breaker laid the technological foundation for several smart-weapon systems that were ultimately fielded with high success. Among these systems are the Joint Surveillance Target Attack Radar System (JSTARS), which integrated PGMs with advanced intelligence, surveillance, and reconnaissance (ISR) systems developed with DARPA support; the Global Hawk unmanned aerial vehicles; a U.S. Air Force air-to-ground missile with terminally guided submunitions; the long-range, quick-response, surface-to-surface Army Tactical Missile System (ATMS), which featured all-weather, day/night capability effective against mobile and other targets; and the Brilliant Anti-armor Tank (BAT) submunition, which used acoustic sensors on its wings to detect and target tanks.
Excimer Lasers
Building on earlier joint efforts, the U.S. Navy and DARPA initiated a new joint program in 1978 with the objective of achieving a laser communications link between aircraft, space platforms or mirrors, and submerged submarines. The ground-based laser-space mirror part of this effort built largely on DARPA efforts toward high-powered, gas-phase excimer lasers (that could emit in the shorter, more water-penetrating region of the electromagnetic spectrum) that had led to the demonstration of a workable, moderate power, laser-optical receiver combination. Additional DARPA work on compensating for atmospheric effects on laser propagation fed into this project and were transferred to the Strategic Defense Initiative (SDI). The project yielded an efficient laser-receiver and a narrowband, matched-wavelength excimer-Raman converter laser system, which was used in successful demonstrations in 1988 of aircraft-to-submerged-submarine communication in 1988, after transfer of the Submarine Laser Communications-Satellite (SLCSAT) program to the Navy in 1987. Soon after, however, the Navy and DARPA agreed that the risks and expenses in developing new solid-state for the blue-green lasers would perhaps be more acceptable than those associated with going ahead with the gas-excimer laser systems in space. Excimer lasers would expand into medical arenas, especially for corrective eye surgery.
| History |
Parts for the Hubble Space Telescope
The National Aeronautics and Space Administration’s (NASA) Hubble Telescope takes the clearest images of the universe and transmits these to Earth via its antennas. From 1978 to 1980, DARPA funded the design, fabrication, delivery and installation of two antenna booms for the Hubble Space Telescope to demonstrate the advantages of metal-matrix composites. Made of a graphite-fiber/aluminum matrix, these booms permit radio frequency conduction while simultaneously serving as structural supports. Deploying this dual-use composite material resulted in a 60% weight savings over an alternative boom- design candidate. Through this new material technology, DARPA met NASA’s design requirements for weight, stiffness, and dimensional stability. DARPA also contributed to the Hubble’s optical successes. The telescope incorporates algorithms and concepts pioneered by DARPA’s Directed Energy Program in the late 1970s and early 1980s, by which mirrors can be deliberately deformed to correct for wavefront imperfections.
Aluminum-Lithium Alloys

In the late 1970's, DARPA initiated a program with Lockheed Space Systems Division to develop the technology of welding aluminum-lithium alloys, which would combine high stiffness with low density and therefore lower weight. At the time, no one understood how to prepare these materials for welding and how to control impurities in the metals and welding process. Such control would be critical for producing materials repeatedly with predictable behavior and performance.

Within 18 months, metallurgists at Lockheed had developed the welding techniques for the 80/90 Al/Li alloy and applied it to the construction of space hardware. One of the most impressive structures made from this material was the Titan missile payload adapter, which was 14 feet in diameter and 17 feet high and fabricated from 3" thick metal plate. By using this alloy, a 10% weight saving was achieved compared to the prior incarnation of that rocket components. The weight savings translated into millions of dollars at cost savings when it came to delivering hardware to obit. This material system made it into classified DoD applications as well. Lockheed scaled the process up to 400,000 lb/year of Al-Li alloys for the next four years.

Defense Sciences Office
DARPA established the Defense Sciences Office (DSO) in 1980, combining the Nuclear Monitoring Research Office, materials science research, and cybernetic technology efforts into a single office. Since its inception, DSO has spawned two additional technology offices at DARPA: the Microsystems Technology Office (MTO) in 1992 and the Biological Technologies Office (BTO) in 2014.

In the mid-1970s, high-energy lasers showed great promise for anti-air warfare and in particular anti-ballistic missile defense. DARPA supported many technology and early system concepts for tactical high-energy lasers. This support culminated in DARPA funding the development of the Baseline Demonstration Laser (BDL) and the Navy ARPA Chemical Laser (NACL), the latter with a joint funding arrangement with the Navy.

Concurrent with these systems programs, DARPA funded the Special Laser Technology Development Program, which led to many advanced components and concepts. These concepts formed the bases for several developmental laser systems. Most noteworthy were the Mid-Infrared Advanced Chemical Laser (MIRACL), a massive megawatt device that relied on rocket-engine-like combustion and that first lased in 1980, and the Chemical Oxygen-Iodine Laser (COIL). The latter forms the basis of the Air Force’s Airborne Laser (ABL). In a later demonstration, the MIRACL system shot down a live, short-range rocket at White Sands Missile Range. The success led to the initiation of an operational system concept study by TRW to develop a Theater High-Energy Laser (THEL). Although the system demonstrated the capability of in-flight destruction of live artillery and the destruction of several rockets in a single day, the program ended in 2006. Even so, high-energy laser development has continued toward a pathway of operational capabilities.

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In the mid-1970s, DARPA and the U.S. Air Force jointly developed an airborne target-acquisition and weapon-delivery radar program, Pave Mover, under the Agency’s Assault Breaker program. The Pave Mover system relied on even earlier DARPA-sponsored research into moving target indication (MTI) radar for detecting slowly moving targets. As the program progressed, researchers added a synthetic aperture radar (SAR) to analyze areas for which the MTI radar could not detect a moving target, as well as capabilities for detecting helicopters and even rotating antennas. Also originally a part of Pave Mover was a weapon guidance feature.

These and other technologies became the basis for the Joint Surveillance and Target Attack Radar System (JSTARS) in the 1980s. And by the early 1990s, the system proved its value in Operation Desert Storm as real-time support to commanders for both battle-area situation assessment and targeting roles.

Although both the radar and the weapon guidance elements were demonstrated in the DARPA Assault Breaker program, the weapon guidance part was later dropped from the Joint STARS Program. In 1996, the Department of Defense approved JSTARS for production and deployment. The Air Force executed contracts with Northrop Grumman to modify seventeen Boeing 707-300 series aircraft into what a fleet of E-8C JSTARS, which have undergone multiple modifications and upgrades over the years.

The Metal Oxide Silicon Implementation Service (MOSIS)
To hasten development in the microelectronics arena of very large-scale integration (VLSI), DARPA funded Metal Oxide Silicon Implementation Service, or MOSIS. The service provided a fast-turnaround (four to ten weeks), low-cost ability to run limited batches of custom and semicustom microelectronic devices. By decoupling researchers from the need to have direct access to fabrication facilities and to negotiate the complexities of producing microelectronic chips, MOSIS opened innovation in this space to players who otherwise might have been precluded. A key aspect of MOSIS was the pooling of several chip designs onto a single semiconductor wafer. MOSIS opened for business in January 1981 and a MOSIS service was still available in nearly 40 years later.
In the early 1980s, DARPA nurtured the development of no-tail-rotor (NOTAR) technologies, resulting in significantly quieter helicopters that could operate with a lower chance of detection. DARPA’s support helped to show the operational advantages of the NOTAR flying demonstrator led to a NOTAR series of helicopters used by government agencies and the commercial sector. The NOTAR system was considered to be the first successful fundamental configuration change to the single-rotor helicopter since the incorporation of the turbine engine in the late 1950s and early 1960s.
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Tacit Blue

DARPA embarked on the pathbreaking research and development that would lead to stealth technology in the 1970s. A milestone in that R&D trajectory was the production of two demonstrator aircraft by Lockheed in what was called the HAVE BLUE program. This resulted in the first practical combat stealth aircraft, which made its first test flight by the end of 1977. A year later, the company received a contract to scale-up engineering development of what become the F-117 and which became operational in October 1983. In 1976, Northrup received a sole-source grant by DARPA to develop the BSAX aircraft, later named TACIT Blue aircraft, which could operate radar sensors while maintaining its own low radar cross-section. The experimental aircraft first flew in 1982 and the many stealth, radar, and aerodynamic innovations it incorporated laid foundations for development of the B-2 stealth bomber, which was first used in combat in 1989.

Stealth aircraft destroyed key targets in conflicts in Iraq, both in the 1991 Desert Storm operation and in 2003 during Operation Iraqi Freedom; in Afghanistan during Operation Enduring Freedom in 2001; and in Libya in 2011. Complementing the key contributions of stealth capabilities in these missions was Department of Defense’s use of other technologies, including DARPA-enabled precision-guided munitions deployed by stealth and non-stealth aircraft. Since their initial development and deployment, stealth technologies have been applied to a wide range of weapon systems and military platforms, among them missiles, helicopters, ground vehicles, and ships.

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Miniaturized Global Positioning System Receivers

With roots extending to the DARPA-supported Transit program—a Navy submarine-geopositioning system originating in the earliest years of the Space Age at the Johns Hopkins University Applied Physics Laboratory—what became today’s world-changing GPS technology began to take modern form in 1973. That is when the Department of Defense called for the creation of a joint program office to develop the NAVSTAR Global Positioning System.

In the early 1980s, as this network of dozens of satellites and ground stations became ever more operational, Soldiers on the ground had to heft around bulky and heavy PSN-8 Manpack GPS receivers. In 1983, in response to a Marine Corps Required Operational Capability to lighten warfighters’ loads, DARPA re-emerged in the GPS-development landscape, focusing on miniaturizing GPS receivers. That effort created a context in which an industry participant in the development process, Rockwell Collins, took the baton to produce a gallium arsenide hybrid chip that allowed for combined analog and digital functionality and the first “all-digital” GPS receivers.

Miniaturized GPS technology has significantly improved the U.S. military’s ability to attack and eliminate difficult targets and to do so from greater distances—fundamentally and progressively changing strategy and enabling successes during the Cold War, the Gulf War, and in more recent conflicts in which the United States has had to contend with dispersed and elusive foes. It also has had transformative effects throughout society. Perhaps most emblematic of this ongoing technology revolution is that soothing voice saying, “Turn right at the next corner,” from your smart phone’s navigation application (and the arguably less soothing declaration, “Recalculating”).

Sea Shadow

Drawing inspiration from his work on the F-117 stealth aircraft, Ben Rich, then head of Lockheed’s Skunk Works, proposed applying the technology concepts he and his colleagues had learned for aircraft to submarines, with the idea of making these vessels undetectable via sonar. Initial tests on a small model suggested the stealth gains could be on the order of a thousandfold, albeit with a cost of speed due to the design.

The Department of Defense did not show interest in this line of investigation until Rich, with input from a colleague, adapted the idea to apply to surface ships. This led to a DARPA contract to apply stealth concepts and materials to surface vessels and to test the effects of seawater on the radar-absorbing materials.

Developed in great secrecy, a prototype, the Sea Shadow (also designated as IX-529) was assembled out of sight within a submersible barge (the Hughes Mining Barge 1) in Redwood City, California. The Sea Shadow’s first trials in 1981 proved greatly disappointing because the ship’s wake was unexpectedly huge and detectable with sonar and from the air. After discovering that the problem was due the motor propellers, which had been installed backwards, the project moved forward. The vessel was completed in 1984 and underwent night trials in 1985 and 1986. Even so, the Sea Shadow never made it beyond the testing phase, though engineers applied lessons learned in such applications as submarine periscopes and some newer Navy destroyers, including the DDG 1000 Zumwalt-class ships. In 1993, the public got it first view of the stealth ship, which eventually was scrapped in 2006.

X-29: The Most Aerodynamically Unstable Aircraft Ever Built

The December 1984 test flight of the X-29—the most aerodynamically unstable aircraft ever built—demonstrated forward-swept wing technology for supersonic fighter aircraft for the first time. Technology breakthroughs, among them a digital fly-by-wire flight-control system and carbon-fiber wing technology, made possible a lightweight design far more maneuverable than conventional aircraft. DARPA, NASA, and the U.S. Air Force jointly developed two X-29 technology demonstration aircraft, which the Air Force acquired in March 1985 and used for 279 test flights by April 1990.

Although Air Force fighter designs ultimately embraced DARPA’s stealth revolution rather than the high maneuverability promised by forward-swept wings, other X-29 technologies found their way into future aircraft. Advanced composite materials are now used extensively in military and commercial aircraft. Aeroelastic tailoring to resist twisting under flight loads is now a standard tool for advanced designs with relevant outcomes including the long, thin wings of the Global Hawk, an unmanned surveillance aircraft.

Global Low Orbiting Message Relay (GLOMR)

The goal of the Global Low Orbiting Message Relay (GLOMR) satellite (aka CHEAPSAT) program was to demonstrate the feasibility of building a two-way, digital data communication satellite capable of performing important military missions for less than a million dollars in under a year. The broader objective was to demonstrate low-cost satellite construction technology that could pave the way for future satellites performing diverse missions.

Under DARPA sponsorship, Defense Systems, Inc. (DSI) designed and developed GLOMR. The spacecraft was placed into orbit from a getaway special canister (or GASCAN) aboard the Space Shuttle Challenger (Mission 61-A, Spacelab D-1) on October 30, 1985, and operated successfully on orbit for over 14 months, before it fell back into the Earth’s atmosphere.

A series of tests, including the use of a portable access terminal at DARPA, were conducted between Washington, D.C., and Santa Barbara, California, demonstrating two-way, cross-country communications via GLOMR. DARPA assisted in transitioning the capability of, and lessons learned from, the GLOMR program to the Defense Department (DoD) and other government agencies.

The GLOMR program demonstrated the feasibility of low-cost satellites. This spacecraft served as a model for many DoD and non-DoD uses, including communications, tracking of beacons, remote- sensor readout, and classified applications.