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

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.
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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 1999.

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.