Research Agency's Innovation Endures

June 2007
By Clarence A. Robinson Jr.

The Defense Advanced Research Projects Agency’s Falcon small launch vehicle blasts off from the U.S. Army test site, Kwajalein Atoll, in the Marshall Islands. The Falcon program consists of the launch vehicle and the Falcon hypersonic technology vehicle. This program includes launching a series of new, low-cost, 1,000-pound-class launch systems to deliver hypersonic test vehicles to near space and satellites into orbit.
Wireless, mobile, net-centric research allows tactical, secure, self-forming, ad hoc networks.

The role of a relatively small defense agency operating from a high-rise office building not far from the Pentagon is to color outside the lines. This entrepreneurial organization has done that for 50 years and in the process has become a driving force in academia, industry and the military with one scientific breakthrough after another. The agency’s technology advances continue to change the way the United States conducts warfare with startling battlefield triumphs.

The only U.S. Defense Department organization not tied to a specific operational mission, the Defense Advanced Research Projects Agency (DARPA) searches worldwide for revolutionary high-payoff ideas and sponsors them, according to Dr. Anthony J. Tether, DARPA’s director. “The agency sponsors these important technology concepts that bridge the gap between fundamental discoveries and their military applications,” he states. “The idea is to provide advances in technology to commanders before they even know they will need or ask for them.”

As examples, DARPA began developing technologies for stealth aircraft in the early 1970s under the Have Blue program, which led to the Air Force’s F-117 tactical fighter. The agency followed that with the Tacit Blue technology demonstration, contributing directly to the B-2 stealth bomber. Other aircraft programs include the unmanned Global Hawk and the Predator. The most well known of DARPA technologies is the Internet, which began as the Advanced Research Projects Agency Network, or ARPANet, with associated transmission control protocol/Internet protocol (TCP/IP) and packet switching—the fundamental elements of both public and private networks.

DARPA’s budget this year is approximately $3.1 billion, and roughly half of its personnel are technical people. The agency supplies technological options for the entire Defense Department and is designed to be a specialized engine to transform the department. Tether points out that this is a unique role within the department, where operational components tend to focus on the near term because of urgent needs and requirements. “A large organization like the department needs DARPA, whose only charter is radical innovation,” he adds.

During an interview in DARPA headquarters, Tether stressed a number of agency programs and made available the organization’s strategy and congressional testimony. “This plan provides a list of significant technical research programs for future icons that we believe will eventually prove to be memorable DARPA accomplishments,” he declares.

These icons include basic and applied research and development that someday may be incorporated in fielded systems and even prototypes of some systems. “DARPA rarely engages in development of full systems to the point that the systems can be used in the field as any other weapon or system might be. However, if we get the concepts right, if we learn the right things from the research and if the technology proves out, then we have successful icons,” Tether says.

“Among these icons are DARPA’s fundamental laws of biology program to bring a deeper mathematical understanding and accompanying predictive ability to the field of biology, with the goal of discovering basic laws that extend across all size scales just as with the Newton’s laws or the laws of physics,” Tether continues. The high-energy liquid laser area defense weapon is another future icon. The technology would provide novel, compact, high-power lasers, which would make practical small-size and low-weight speed-of-light weapons for tactical mobile air and ground vehicles.

One icon is self-forming networks that are robust, self-defending at the strategic and tactical levels and are key to network-centric warfare. Yet another is a miniaturized chip-scale atomic clock to provide very accurate time required for assured network communications, especially should the global positioning system (GPS) ever fail.

Manned and unmanned air vehicles that quickly arrive at their mission stations and loiter for long periods are another of the icons (see page 43), as are space systems. The U.S. military’s ability to use space is a major strategic advantage, and DARPA is working to ensure that the United States maintains that advantage (see page 25), Tether explains. Other DARPA icons include high-productivity computing systems—supercomputers that are fundamental to a variety of military operations, from weather forecasting to cryptography to the design of new weapons. The agency is working to maintain the nation’s global lead in this technology.

“Real-time accurate machine language translation of structured and unstructured text and speech with near-expert human translation accuracy is another DARPA icon,” Tether continues. “Quantum information science is also an icon, to exploit quantum phenomena in the fields of computing, cryptography and communications with the promise of opening new frontiers in each area.”

Tether earlier served at DARPA as the director of the Strategic Technology Office, where he was involved in space-based high-energy chemical laser weapons work before the Soviet Union imploded. He had received a bachelor’s degree in electrical engineering from Rensselaer Polytechnic Institute, which he followed with master of science and doctoral degrees from Stanford University.

A lot of people were unaware that the B-1 bomber was slated to have a high-energy laser weapon integrated in the platform. When the B-1 was canceled in favor of the B-2 stealth aircraft, the laser concept was held up. Later, the decision was made to not use the laser on the B-1B when the aircraft went into production, Tether verifies. Today lasers have multiple military uses, from sensing to communications to electronic warfare to target designation. DARPA has been involved in lasers and laser technology since the early 1960s and continues to work in this important area.

For example, the agency is working on lasers to protect platforms. The high-energy liquid laser area defense system, or HELLADS, program is an icon to develop about a 150-kilowatt laser weapon with an order of magnitude reduction in weight compared to existing systems. Tether reveals that the HELLADS’ weight goal is for less than 5 kilograms per kilowatt. This goal would allow new and innovative capabilities such as use on tactical aircraft for self-defense against even the most advanced surface-to-air missiles.

This year the HELLADS program demonstrated 15 kilowatts of multimode laser output power. If successful, the laser system will transform operations and provide a tremendous advantage for U.S. forces, Tether says. DARPA also is working to improve laser component technology. For example, the super high efficiency diode sources, or SHEDS, program has achieved 70 percent electrical-to-optical efficiency in generating light from stacks of semiconductor diode laser bars, a dramatic improvement over today’s 50-percent-efficient diode technology.

More than advanced components drive DARPA efforts. “At the core of network-centric operations to transform the Defense Department is the promise to turn information superiority into combat power, conducting operations far more quickly and effectively than any adversary,” Tether claims. “The networks must be as reliable, available, secure and survivable as the weapons and forces they connect. They must distribute huge amounts of data and precisely across a battlefield, theater or the globe.

“For these networks to realize their full military potential, people can no longer be central to establishing, managing or administering them. The networks must be able to form, manage, defend and heal themselves so they always function at the enormously high speeds that provide their advantages,” he acknowledges. DARPA also is developing technologies for wireless tactical network-centric warfare that will enable reliable, mobile, secure, self-forming, ad hoc networking among various echelons with the most efficient use of available spectrum.

The Wasp micro air vehicle from the Defense Advanced Research Projects Agency is launched during a U.S. Marine Corps exercise at Twentynine Palms, California. The Wasp is a quiet, reliable and rugged unmanned air vehicle designed for front-line reconnaissance. The air vehicle has a 13-inch wingspan, weighs approximately one-half pound and provides immediate surveillance with two onboard color video cameras for more than an hour.
“A seminal DARPA tactical networking program is the small unit operations situational awareness system that links together dismounted soldiers operating in difficult environments such as cities and forests. This self-forming and self-healing communications technology transitioned to the Army, where its basic network waveform is being integrated into ground mobile radios and handheld, manpack, small form-factor radios,” Tether relates. The next logical step was to move from connecting individual soldiers to connecting ground and airborne vehicles.

The Future Combat Systems-Communications (FCS-C), also called the DARPA Network Centric Radio System, program developed a gateway approach. This technology makes possible a mobile, self-healing ad hoc network for ground maneuver vehicles and unmanned air vehicles operating in cluttered, complex terrain, including an urban environment. “Radio interoperability has plagued the Defense Department,” Tether observes. “A special feature of the Network Centric Radio System is that interoperability is built into the network itself, rather than having to build it into each radio. Any radio can now interoperate with any other. We showed that it is possible to have previously incompatible tactical radios talk seamlessly among themselves and to more modern systems, including both military and commercial satellite systems.” This technology is transitioning to the U.S. Special Operations Command, Tether discloses.

“Complementing this is our work to compensate for the difficult physical and frequency environments in which our tactical units may need to communicate,” he continues. “Tactical units sometimes have to work in the uniquely cluttered environments of cities, which creates problems because signals bounce around and take multiple paths that degrade links. The Mobile Multiple Input/ Multiple Output [MNM] program is turning this problem into an opportunity by actually exploiting the multipath effect to improve communications between vehicles moving in cities without a fixed communications infrastructure. MNM was recently tested using several vehicles operating at speeds of 45 to 60 miles per hour in complex terrain, and the technology transferred more data using less bandwidth than the program’s goals.”

The military frequency spectrum is cluttered and limited in extent, with most of the spectrum already allocated to users who may or may not be using it at a given time and place. The Next Generation (XG) communications program is developing the technology to increase radio spectrum availability by 10 times by taking advantage of spectrum that has been assigned but is not being used at a particular point in time, Tether confirms. “XG technology assesses the spectrum environment and dynamically uses spectrum across frequency, space and time. XG also is designed to be successful in the face of jammers and without harmful interference to commercial, public service and military communications systems,” he explains, adding that the technology is transitioning to the Army.

Tether continues that it is also essential that tactical and strategic networks are secure. DARPA is developing technologies to make networks not only more secure but also disruption-tolerant and, when attacked, self-reconstituting. “Networks rely on a widely available timing signal, or common clock, to sequence the movement of voice and data traffic,” he points out. “The timing signal is provided by GPS, and we should expect our adversaries to attack our networks by denying us the use of GPS signal.

“To protect the networks, DARPA is developing microelectromechanical systems [MEMS] technology to create a miniature atomic clock—measuring approximately 1 cubic centimeter—to supply the timing signal should the GPS signal be lost. The Chip-Scale Atomic Clock [CSAC] will allow a network node, such as a soldier using a single channel ground and airborne radio system [SINCGARS] to maintain synchronous operation with the network for several days after loss of the GPS signal,” Tether adds. “Last year we demonstrated the first CSAC the size of a pager that maintains time accurately to within 1 second over 200 years.” Plans are to insert CSAC into SINCGARS to demonstrate its capability.

DARPA is tackling one of the most important roadblocks to increasing chip feature integration—heat dissipation. As both the number of transistors on a chip and their clock frequency increase, the waste heat generated rises sharply. Today some chips generate as much heat per square inch as a hot plate, and as a result, faster chip clock speeds cannot be used, which threatens to break Moore’s law.

So, the agency is pursuing three ways to push through the heat dissipation roadblock. “We are looking at an entirely new type of transistor, called a tunneling transistor, that would operate at lower voltages—1/4 volt instead of today’s 1 volt—thereby greatly reducing the active heat dissipation, which is proportional to the square of the voltage,” Tether states.

“The second approach is to reduce the standby heat dissipated when a transistor is nominally off but still leaks a small amount of current. This problem has increased in recent years as transistors have become smaller. One possible solution is nano-electromechanical switches that would physically disconnect, or unplug, a transistor when it is off, preventing leakage current that generates waste heat,” Tether allows.

Third, DARPA is working to reduce the heat dissipated by the interconnects, or wires, that connect the active devices within a chip, which are another important heat source. To limit the heat from wire interconnects in integrated circuits, DARPA is pursuing the replacement of the longer metal wires with optical interconnects. This approach would generate far less heat.

Of DARPA’s 240 personnel, 140 to 150 are scientists and engineers. All of the technical people are there for only four or six years by contract. They come from industry and academia and are attracted to the agency to accomplish technology development they might otherwise never have an opportunity to be a part of, Tether makes clear. “They know they are not here for a career, only for a relatively short time and must give up everything including their previous job and move to a new area. Recruiting them is all about ideas, and while they may not finish the program in the specified time, they are motivated by those ideas and can make a healthy start,” he says.

“DARPA’s mission imperative is to avoid technological surprise for the U.S. military and to create that surprise for our adversaries. The agency’s business processes reflect this in a straightforward way—bring in expert, entrepreneurial program managers; empower them; protect them from red tape; and quickly make decisions about starting, continuing or stopping research projects,” Tether asserts.

Web Resources
DARPA technical offices’programs:

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