"The Next Century of Air Power," Feature Article, November 2003

ON THE COVER/FEATURE FOCUS:
Future Engineering Systems

the next century of air power

The U.S. Air Force is engineering a transformation of defense, in the sky and above it.

by Paul D. Nielsen, Ahmed K. Noor, and Samuel L. Venneri

As we approach the 100th anniversary of powered flight, engineers and scientists from the broad aerospace community have much to celebrate. A century of innovation and perspiration has created a worldwide aerospace industry that has taken us from Kitty Hawk to Tranquility Base and beyond. It has borne a commercial airline system that has enriched our lives and shrunk the world, and it beta-tested a technology development model that has spawned many of the 20th century's high-tech industries. Scientists and engineers must be mindful of this great legacy, honor their predecessors—and then get about creating the next century of air and space technology.

In the United States, the commercial aerospace industry has been a dominant sector in the economy and the defense aerospace industry has been a vital component of national security. Our continued economic growth and national security in the 21st century will depend on strong U.S. leadership in the broad aerospace sector.

This is an especially great time to be a technologist in the aerospace sector. There are many challenges, but there are also unbounded opportunities. Some are evolutionary—and some are truly revolutionary. Much of this is driven by competition between highly evolved systems with foundations in the 20th century and new systems conceived in the 21st century. For example, even as fifth-generation aircraft like the F/A-22 and the F-35 enter production, increasingly capable unmanned aerial vehicles are scratching for their own niche. Although precision munitions are smaller, more precise, and more autonomous, weapons using directed energy are beginning to emerge.

THE NEXT GENERATION

Will this be the era when air and space operations truly become aerospace? When space operations finally become routine and highly responsive in nature? Will this be the era when a substantial portion of the world's almost totally subsonic air fleet transitions to supersonic or even hypersonic flight? What are the limits to miniaturization? How do we integrate new systems with old?

These are questions with tremendous consequences—and they open a fertile world for researchers, innovators, and entrepreneurs. The accelerating advances in broad-based areas such as information technology, nanotechnology, and biotechnology as well as more military-oriented concerns such as high-power directed energy, electronic warfare, intelligence, surveillance, and reconnaissance provide opportunities for realization of systems that were only dreams in the past century.

The U.S. Air Force has been pursuing the transformation of air and space power through development of technologies that yield new capabilities and by adopting novel operational concepts that enhance our ability to achieve desired military effects. Maturing a comprehensive set of technologies is the mission of the Air Force Research Laboratory.

The transformation includes migrating military capabilities to unmanned platforms for a wide range of air applications and developing new directed energy capabilities, which produce effects on the battlefield ranging from the traditional destruction of enemy equipment to the revolutionary non-lethal, non-destructive stopping of advancing enemy troops.

NOBODY ON BOARD

Current and future concepts for unmanned aerial vehicles, or UAVs, are offering new horizons for air and space operations. Today, we are witnessing UAVs beginning to play critical roles in war. They are performing invaluable surveillance missions, supporting both air and ground forces with timely and accurate intelligence and reconnaissance, and they are delivering ordnance with precision accuracy. UAVs will undoubtedly continue to make revolutionary advances.

Up to this point, the role for unmanned vehicles has traditionally been to gather intelligence, surveillance, and reconnaissance information. UAVs have already demonstrated that this mission is indeed a service where they can provide outstanding capability.

WEEKS ALOFT INSTEAD OF HOURS

The next century of flight will see the roles of future unmanned vehicles merging with those of space-based assets as technology allows them to fly higher, longer, and with more capable sensor packages. Typical capabilities of these next-generation unmanned observation vehicles will include continuous 360-degree sensor coverage flying from altitudes exceeding 60,000 feet, increased survivability gained from improved low-observable technologies, and mission duration times exceeding 40 hours per sortie. Further development of solar-electric propulsion and fuel cells may lead to mission duration times measured in weeks rather than hours.

Indeed, UAV technology will narrow the differences between air and space vehicles, as they begin to function more like very low-orbit, persistent satellites than like aircraft. However, unmanned vehicles will offer increased mission flexibility over space-based platforms that have their locations fixed in an orbit over the Earth.

Future combat operations will witness a dramatic increase in UAV involvement. Recent military contingencies have already demonstrated the utility of integrating sensors and weapons on a common unmanned platform.

Vehicles being planned at the Air Force Research Laboratory include unmanned planes for surveillance and reconnaissance.

The Department of Defense is currently developing the Joint Unmanned Combat Air System, or J-UCAS, which is envisioned as a low-observable strike platform capable of using advanced on-board sensors to find targets and of delivering precision munitions in a time-effective manner. The J-UCAS will be able to carry most of the precision weapons in the current and future arsenal, including the 2,000-pound Joint Direct Attack Munition, and the 250-pound Small Diameter Bomb, much like future manned strike aircraft, but with the goal of achieving similar capability at a fraction of the cost.

The military men and women executing combat operations, collectively known as the warfighter, will witness the most striking UAV technological gain in the area of autonomous control. Instead of one pilot on the ground operating one vehicle as currently performed in Predator operations, there will be a single mission commander operating multiple UAVs from as far away as the other side of the world. The mission commander will not perform stick and rudder commands, but will instead give broad mission-oriented commands to the networked UAV flight packages.

The vehicles themselves will have the on-board intelligence capable of autonomously performing tasks such as optimal in-flight routing and coordinated target prosecution. UAVs will also have an autonomous in-flight refueling capability that will extend their potential range substantially.

In this century, UAVs will become fully integrated into daily operations. Today, UAVs operate by exception in an airspace dominated by manned flight vehicles. The goal in the next hundred years is to seamlessly integrate UAVs in the same airspace with manned assets, including the commercial airplanes.

The first task required will be to make UAV operations transparent to the air traffic management system. Airspace integrity and safety will be ensured by collision avoidance systems that will automatically separate UAVs from one another as well as from manned aircraft. These systems will approach, and eventually exceed, human performance in "see and avoid" capability.

UAV operators will be not be pilots in the traditional sense. They will function as managers of UAV teams.

DIRECTED ENERGY

Precision weapons have proven their value over the last 20 years and have been a deciding factor in all of our recent large-scale military operations. However, the precision weapon of the second century of aerospace may not always carry traditional kinetic warheads like those today.

Directed energy weapons, both laser and high-power microwave, are beginning to emerge as future options for military commanders. These new concepts will provide both the traditional destructive capability of today with a new capability to temporarily or permanently disable an enemy target rather than to destroy it.

The best-known current application of high-power directed energy is the Airborne Laser, or ABL, program now in developmental testing. With roots stretching back to the Airborne Laser Laboratory of the 1970s, the system places a weapons-class chemical laser aboard a modified Boeing 747-400 freighter. Its mission is to destroy enemy ballistic missiles shortly after launch while they are still in the boost phase of flight.

Combat operations of the future may see officers giving commands to fleets of unmanned vehicles that are able to carry out orders on their own.

There are actually four lasers onboard this aircraft, as well as advanced optical systems, a sensor suite, and a state-of-the-art computer system. These individual elements function as a system of systems to find, track, and destroy enemy missiles. After onboard infrared sensors detect a boosting missile, the information is relayed to a kilowatt-class laser that locates the missile, reports detailed flight profile data, and begins a track file. Then, the Track Illuminator Laser locks onto the missile and determines the optimum aim point for the high-energy laser. Next, the Beacon Illuminator Laser measures atmospheric turbulence and provides the compensation data to the adaptive optics system. Finally, the heart of the system, the megawatt-class chemical laser, fires and heats an area on the missile body sufficiently to cause its structure to fracture under the pressure of the missile's internal fuel and oxidizer load.

Although the exact lethal range is classified, the
U.S. Air Force has publicly announced that the ABL can effectively perform from a distance of "hundreds of
kilometers."

High-power microwaves, a second directed energy technology, can produce innovative soft-kill, or non-lethal, effects. It has huge potential in command and control warfare, in suppressing enemy air defenses, against tactical aircraft or unmanned aerial vehicles, including missiles, and in airbase defense. When high-power microwaves encounter present-day microelectronic systems, the results can be disastrous to the electronics. Microwaves can cause systems to burn out and fail, or to function improperly.

Unmanned vehicles may hover over battlefields until they are needed, or remain at high altitudes for extended flights, to take over some of the jobs of low-orbit satellites, but to do it with more flexibility at a lower cost.

A short burst of high-power microwave energy, while being lethal to the electronics, will have basically no effect on humans operating the equipment. The low collateral damage aspect of this technology and the heavy reliance on electronic components in today's weaponry make microwave weapons attractive in a wide variety of missions, especially where avoiding civilian casualties is a major concern.

At lower power levels, beam microwaves can also be used to prevent intrusion by unauthorized individuals without hurting them. If the proper frequency and waveform are selected, millimeter wave energy will penetrate less than 1/64 of an inch into an individual's skin, stimulating the pain sensors and causing an experience of severe pain without physical damage.

This idea can potentially provide an effective, non-lethal means of deterring aggressors or intruders. It is becoming an increasingly important capability as the United States encounters more urban environments in military operations.

COMMAND AND CONTROL

Just as civilian information systems have experienced rapid growth over the last decade, so have their military equivalents, command and control systems. The potential for new military capability is staggering.

Combat operations designed to create specific effects on the battlefield are called effects-based operations. They are the centerpiece of 21st century military strategy. In support of these operations, the Air Force lab is developing technology to optimize new command and control concepts, tactics, and tools. The beginnings of this new capability have already matured to the advanced technology demonstration level.

Examples of this technology focus on intelligent software agents, knowledge bases, and data fusion for information gathering and filtering, as well as on enemy center of gravity analysis and decision-making. Next will be the construction of campaign and strategy development assessment tools. Shortly thereafter, an intelligence, surveillance, and reconnaissance assistant will be demonstrated in military exercises and wargames. Throughout the demonstration, technology to synergistically combine information is being matured to improve knowledge integration and exchange between digital environments.

Informed, on-time decisions that yield the desired military result on the battlefield are the end-goal of effects-based operations. The laboratory is developing additional technology to aid the warfighter in this area also.

Directed energy, in the form of lasers or microwaves, is emerging as a non-lethal alternative to the traditional kinetic warheads of today's precision weapons.

Networked systems, able to pass information from the sensor to the shooter, are becoming the standard for today's military operations. This capability was demonstrated by the Predator and Special Operations' AC-130 gunships in Afghanistan.

The lab is developing the Deployable Theater Information Grid to enable the networked systems of tomorrow. This technology effort will develop command and control software to support seamless connectivity between airborne platforms and the global information network. It will also deliver software that will provide interoperability with older systems.

It will provide improved situational awareness. The warfighter will have improved, modern digital communications, improved interoperability with other systems, and standardized information. The standard will be seamless connectivity from sensor to the decision-maker, to the shooter, and to the weapon.

Transformation of air and space power will continue during the second century of aerospace, most likely at an accelerated pace. The once-independent mediums of air and space are merging as systems become more and more sophisticated.

The technologist has fertile ground on which to plant the seeds of innovation and invention. UAVs will provide opportunities for new military capabilities and can lead to the virtual warfighter era. Civil and commercial applications of unmanned systems might include telecommunications, weather reconnaissance, border patrol, and civil emergency support.

Directed energy weapons will provide military commanders with non-lethal options never before available. The future command and control network will link space, air, and ground assets into an intelligent sensor web that will provide the military commander with an environment that is not unlike the human nervous system. It will enable the warfighter to sense and react as a coherent organism, making use of every piece of information available.

The advanced systems of tomorrow fueled by the technology development of today will provide incredible capability to the U.S. Air Force. The realization of this vision requires new levels of collaboration among diverse multidisciplinary teams and the creation of intelligent knowledge organizations consisting of a skilled workforce, not only from the U.S. Air Force, but also from other government agencies, industry, technology providers, and academia.

Throughout the first century of aerospace, the Air Force Research Laboratory and its predecessor organizations have been guiding science and technology development for the U.S. Air Force. Their guiding principles have remained ever constant.

In the words of Gen. Henry H. Arnold, the last Commanding General of the Army Air Forces and one of the founding fathers of the U.S. Air Force, "The first essential of airpower is preeminence in research."

And it was Theodore von Karman, chairman of the Army Air Force's Scientific Advisory Group (later known as the USAF's Scientific Advisory Board), who said, "Science is the key to air supremacy."

These words, from two of the architects of the Air Force itself, are fundamental principles for the research laboratory, and will remain its cornerstone for the second century of aerospace.

SIDEBAR: AIR MEETS SPACE

Major General Paul D. Nielsen is the Commander of the Air Force Research Laboratory at Wright-Patterson Air Force Base in Ohio. Ahmed K. Noor is Eminent Scholar and William E. Loebeck Professor of Aerospace Engineering and the director of the Center for Advanced Engineering Environments at Old Dominion University in Norfolk, Va. He is also adjunct professor of mechanical and aerospace engineering at the University of Florida in Gainesville. Samuel L. Venneri is the former chief technologist of NASA.