Future options for nonlethal artillery.

Gone is the Berlin Wall.-Gone is the Soviet Union. Gone also is the clearly defined enemy of the past. In its place is an amorphous, loosely knit network of terrorist cells and other hostile forces that do not wage war by the "old rules." The Global War on Terrorism now dominates the daily headlines. Much of what we knew about war has changed dramatically in the past few years.

Americans have grown more intolerant of war casualties. The public expects more sterile battles as precise weaponry demonstrates ever-increasing capabilities. Meanwhile, network television beams real-time war footage worldwide, allowing global audiences to scrutinize battlefield activities.

While Americans and our allies place a high value on life, many of our enemies do not. This growing ethical divide has given the enemy a new tool to use. For example, the Iraqi regime would not hesitate to put anti-aircraft weapons or radar systems in a schoolyard or next to a hospital.

The enemy knows we are reluctant to bomb these installations because of the potential for the loss of innocent lives. The result could be a propaganda dividend for the enemy, rallying anti-American sentiment abroad and criticism at home. This is called the "CNN Effect."

Such circumstances have created a growing need for nonlethal alternatives. We can not only save the lives of both combatants and non-combatants, but also reduce the collateral damage to structures and the environment.

The use of nonlethal weaponry is not new, but the level of interest has grown dramatically in recent years. The term "nonlethal artillery" might seem like an oxymoron to some, but as a concept, it must be pursued if the Field Artillery is to maintain relevance in all aspects of the future spectrum of combat. In fact, the Field Artillery has been firing nonlethal smoke and illumination for many years.

"Less lethal" and "scalable effects" are terms often used interchangeably with nonlethal. While the intent of nonlethal technologies is to avoid lethality, unintentional casualties could result from such things as falling debris or the loss of electrical power in a hospital.

This article reviews a few alternatives that could be considered for artillery delivery. It is not intended to be comprehensive in its description of all possible technologies.

Many excellent reviews of this nature have already been published. One such study is "An Assessment of Nonlethal Weapons Science and Technology" (2002) by the Naval Studies Board of the National Research Council. (The reader can access the study online at the National Academies Press at http://www.nap.edu.books/0309082889/ html/.)

Between the concept and reality of artillery-delivered nonlethal munitions lie many implementation challenges and questions we must address.

The first set is political. We need a paradigm shift to address the mental inertia that defines artillery only in terms of high explosives. We must consider the Chemical Weapons Convention and other treaty limitations. Technology substance must be separated from hype with funding provided to develop the weapons. We also need to consider the implications of proliferation.

Next we need to address design challenges. Can we apply the technology both reliably and predictably? Can we deliver it with sufficient accuracy? How do we disperse the payload and control the distribution or concentration levels of the material? Are volume limits too restrictive, and can the technology be weaponized and survive the launch environments?

Finally we must consider operational issues. How useful and long lasting are the effects? Do they create a problem for friendly forces? What are the countermeasures? Will the terrain, wind or other weather conditions significantly affect the technology? What are the effects of aging and environmental exposure? Are training and logistics requirements reasonable? Do the benefits justify the artillery's not firing lethal rounds--justify storing nonlethal rounds in place of lethal rounds on board? Are there more effective ways of achieving the same results? Is it safe for the user?

All these questions must be answered as potential nonlethal technologies are considered. Here are several with potential for delivery by artillery.

Carbon Fibers. Electrically conductive carbon fibers have disabled power grids in Serbia and Iraq. Thousands of thin filaments are dispensed over electrical facilities, such as substations, transmission lines or generating stations. Floating down like a cloud, they short the electrical circuits and disrupt the enemy's ability to access power. Depending on the target, damage can be slight or extensive, localized or widespread.

Adversaries might implement countermeasures, such as covering substations or switching off circuit breakers, but doing so might invite a more destructive response.

The delivery of the carbon fibers might be accomplished by low-altitude, precisely timed, rapid expulsion. Perhaps more likely would be to extract the payload at a higher altitude, then guide it to a precise location and altitude before dispensing the fibers.

Current bomb versions of carbon fiber weapons reportedly are costly, which might hinder the development of this technology. Implementing an artillery shell with carbon fibers may be challenging, but the shell could provide a useful tool on the battlefield where power systems are a factor.

Thermobarics. As the name implies, heat and pressure are important characteristics of thermobaric weapons. Rapid pressure spikes are characteristic of conventional explosives. By comparison, thermobarics have a much longer pulse of high temperature and pressure. This makes them much more effective against convoluted targets, such as caves and complex buildings.

Fuel-air explosives (FAE) and nanoparticle explosives share some commonality with thermobarics. A small explosive or dispenser initially distributes the energetic material. An automatic (oxygen-induced) or triggered initiation of the material follows that creates the tremendous pressure and heat.

Whether or not and how thermobarics could be used in a nonlethal scenario is a topic of consideration. The difference between lethal and nonlethal pressures and temperatures may be small and could require both triggering and operational solutions to provide reliable nonlethal effects. The potential for scalable output where the destructive force could be field-adjustable makes this technology worthy of consideration as a less-lethal option.

Thermobaric weapons have been used in several armed conflicts. Reasonable countermeasures are virtually nonexistent. Further research probably is warranted to determine the value of a potential scalable-lethality artillery shell.

Engine Disruption. Short- or long-term engine disruption can be an effective nonlethal tool. One way is to block the air filter. An aerosolized solution of polyvinyl alcohol/borate will combine with carbon dioxide to create a sticky polymer that readily adheres to the air filter upon ingestion. With a sufficient quantity ingested, the engine ceases to function as it is starved of air.

The materials are inexpensive and nontoxic, but targeting accuracy is important.

By replacing the air filter, engine operations can resume. Clogging a radiator would be more difficult to remedy. If the air filter is breached, the engine's inhalation of the material will result in severe gumming and its incapacitation.

Various reactive species of materials might disable an engine effectively. Designing the materials for a particular application and delivering the materials to the right place, then dispensing them at the right time are all issues to be addressed.

Immediate engine shutdown might be the only countermeasure and then only if initiated before any active material reached the engine.

Malodorants. These are safe chemical compounds that, due to their characteristic smell, are highly repulsive to personnel. (See Figure 1.) Because the effect is primarily psychological, the response to the stimulus cannot be predicted with accuracy. Temporary in nature, malodorants have little collateral effects.

Liquid malodorant could be dispersed directly from a passing artillery shell. Alternatively, the payload could be ejected from the shell, aerosolized and then dispersed at a prime altitude above the target area.

Another malodorant approach involves using "paint balls" or "Calgon" beads that are ejected at a predetermined altitude and rupture upon impact. A microencapsulated version could survive ground impact and remain poised for passing enemy troops to rupture.

Further, malodorants could be combined with another material, such as an irritant, to create a more effective tool.

Studies have shown cultural and ethnic variability in the degree to which any particular malodorant is objectionable. Further study might be required to find a substance that is universally repulsive. Some success has been found by creating a cocktail of biological odors, such as human waste and vomit.

The quantity of material carried in a shell is obviously limited. Weaponization might be required, although many applications relevant to artillery exist due to the developments of an aerosolizing dispersion generator and a frangible mortar round. ("Frangible" means the shell breaks up into small, lightweight pieces before or during impact.)

A malodorant artillery application warrants further consideration. Because some development work on malodorants already has been completed, costs to deploy this technology could be less than many other options and it could be implemented more quickly.

Irritants. These are natural or synthesized chemicals that irritate the respiratory tract, eyes or skin. They can cause burning and watering of the eyes, making it temporarily difficult or impossible to see. Other possible effects include coughing, choking, and skin itching and burning.

One common irritant is tear gas. Another is oleoresin capsicum (OC) derived from chili peppers. Many others are available, and some are in use. They can be dispensed as powders, liquids or fogs.

Most people quickly seek relief from irritants' effects. Less predictable is the response from highly trained and disciplined troops.

Irritants could be dispensed in micro-encapsulant form, sitting idly until activated by passing troops. Their effectiveness might be further enhanced in combination with another technology, such as malodorants.

Although irritants have the potential to be quite effective, treaty concerns and predictability of response could affect the development of this option.

Combustion Inhibition. This is a technology to use against air-breathing motorized vehicles. A chemical agent is introduced into the combustion chamber air intake that interferes with proper combustion of the fuel and stops the engine.

Ferrocene seems to be one of the more promising compounds. A common antiknock compound in gasoline, it has low toxicity and is effective in very low concentrations.

The chemical could be released by aerosol dispersion, by ruptured encapsulants or in conjunction with another technology, such as airborne microencapsulants.

The engine stoppage is temporary. Once the ambient air and the internal engine air clears, the engine can be restarted.

High winds and rapidly moving vehicles obviously would present a greater challenge. However, if the enemy halted his vehicles briefly at a strategic location, combustion inhibitors could provide a useful advantage. Once the vehicles are halted, friendly forces could fire a continuing barrage of rounds to further inhibit the mobility of the vehicles.

Combustion inhibition could be a useful tool in a commander's arsenal.

Obscurants. As a class, obscurants deny or impair the vision of people or equipment. Smoke generators have been in use for many years, obscuring friendly forces from view and impairing the adversary's viewing capability.

Aerosol fog or particulate obscurants are most common. With advancing technology, more capable obscurants are required.

No single obscurant is effective against all sensors and optics. Fog oil and other smokes are effective in the visual spectrum. Brass and carbon-based particulates are effective in the infrared (IR) spectrum, but they are toxic, causing respiratory irritation and environmental concerns. Tailored hybrids are being researched that could be effective against both IR and millimeter wave (MMW) technologies. A different type of obscurant designed to coat and harden on the surface of exposed optics and viewing ports could be effective but more challenging to deliver. Further development of obscurants may be warranted.

Properly selected and deployed, obscurants are difficult to counter.

Flash-Bang and Light Devices. These interfere with viewing. A flash-bang device typically combines a very loud report with a blinding flash. The combination results in temporary surprise, vision loss, confusion and disorientation without long-term effects. Studies also have shown that intense stroboscopic light will induce nausea and disorientation.

Still other device variations can generate a broadband output of light at high intensity. This explosive device would serve a defensive role and be capable of disabling night-vision optics, heat-seeking sensors and other low-level heat or light equipment.

Flash-bang grenades and similar devices are a mature technology currently in use. The major limitation seems to be the short time of their effectiveness.

Stroboscopic technology is well established, but packaging and delivery are not. These devices probably would need to remain airborne to be effective for an extended period of time. Developing the proper approach and hardware to accomplish this will require some effort.

One concern applicable to all these devices, but probably more so to the broadband light, is the risk to friendly forces. Friendly personnel and light-sensitive equipment could be affected if these tools are not carefully and thoughtfully employed. However, the extended range of artillery systems could negate this issue.

Flash-bang devices seem to be limited to harassment and demoralization of an enemy. A stroboscopic device would be more effective in disrupting operations for a useful period of time, while high-intensity broadband devices could be very effective against optics.

Ground Sensors. These are situated in a relatively fixed location, autonomously collecting and relaying or storing data. Collected data could either be telemetered or archived for later interrogation. Because sensors are passive in nature, they have no direct effect on an adversary.

These devices could sense chemical, biological or radiological materials. They could measure vibration or sound, detect motion or monitor an area with a microphone or video camera. The possibilities are many, depending on the need.

One example is the compact biological unattended ground sensor (CBUGS) that originally was designed to be packaged in an artillery shell. (See Figure 2.) The device monitors the air for the presence of biotoxins. Airborne species are collected and analyzed using laser-induced fluorescence. Having this kind of information available would increase troop safety and allow for a more informed, potentially less-lethal response to an adversary.

Sensors could monitor their surroundings for weeks or months, storing or transmitting the data. Without camouflage, they might be spotted and disabled by the enemy. The technology has been demonstrated, but further weaponization is needed.

"Smart Dust." The miniaturization of hardware and growth of microelectromechanical systems (MEMS) technology has led to the development of smart dust and other tiny sensors. (See Figure 3.) Small enough to be blown in the wind, such a sensor can monitor temperature, motion, humidity and other parameters. Each sensor is self-sufficient with its own power supply and electronics and communications hardware.

Currently several cubic millimeters in volume, these sensors soon will be the size of a grain of sand. Dozens, hundreds or thousands could be deployed to create a massive network of sensors that would be queried by an interrogator.

Smart Dust could act as "sentries" to provide advanced warning of enemy activities, protecting friendly forces and allowing them to deny the enemy specific terrain. It also might provide battle damage assessment (BDA).

Among the challenges is the development of low-powered, robust communications and energy storage or generation that could operate sensors for months or years. Properly designed, some sensors might be able to stay aloft for hours. Artillery application would require packaging, dispersion and a method for interrogating the sensors.

This evolving technology is being explored by many organizations. The suite of sensors available is likely to expand greatly over the next several years. Though many will be larger than a cubic millimeter, they should be small enough to provide discreet monitoring in the air or on the ground. Smart dust could have a great future as a military tool.

Taggants. These mark or identify personnel or equipment for subsequent monitoring or identification. Various paints and dyes, both visible and invisible, can be applied either overtly or covertly. Some are designed to be fluorescent under ultraviolet or other types of light. Taggants may provide the opportunity for a less-lethal response in certain conditions.

The type of taggant that is more likely to be artillery-delivered is the electronic tag. These small devices could be active or passive, providing information to the observer about motion or location. Active tags would have batteries and initiate data transmission, while passive tags must be interrogated to provide information. Transmission distances in these devices are currently quite limited.

As a corollary to the smart dust sensor technology, the taggants could be so small and inconspicuous that they might be readily deployed without detection.

High Power Microwave (HPM). These devices are in the directed-energy class. A brief, high-powered pulse induces a high-voltage spike in the electronic circuit of the targeted system.

The ability of the microwave energy to damage the intended circuitry is affected by factors such as the surrounding structure, the physical design of the target, design of the circuitry and duration of exposure. The voltage spike can result in electronics that are confused, damaged or destroyed, thus degrading or terminating the device's ability to operate.

The high microwave frequency (typically between 300 MHz and 300 GHz) is more effective at coupling with the circuits than are lower frequency emissions. Especially vulnerable to HPMs are those systems with an antenna, providing a ready conduit for microwave energy to enter the system.

Countermeasures to HPM are difficult and expensive.

As with many technologies, HPM is size-limited in an artillery application. This in turn will limit the power available and radius of influence. The use of HPMs seems feasible but challenging due to size constraints and flight environments.

A properly designed, built and delivered weapon could be very effective in limiting the warfighting capabilities of an enemy without unnecessary loss of life or collateral damage. With the growing dependence on electronic circuitry on the battlefield, HPM weaponry looks very appealing.

Foams. Several types of foams have nonlethal applications. Hardening foams can be used to deny or limit access to vehicles, equipment or buildings. Neutralizing foams are able to decontaminate and neutralize biotoxins and chemical agents.

Sticky foams are useful for crowd control, access denial and mobility restriction. This incredibly aggressive foam sticks so well that it can quickly incapacitate an individual. Sprayed on a door handle, the person would get stuck trying to open the door.

While possessed of intriguing potential, the utility of foams in artillery applications is questionable. The foam's volume is limited by the projectile size. Coupled with requirements for precise delivery followed by precise application, foams of any type don't appear to be good candidates for artillery applications.

Other Technologies. Dozens of other technologies that are potentially nonlethal in nature probably are not well suited for artillery consideration. For example, super lubricants that are slippery agents and anti-traction compounds are not suitable for artillery delivery. The challenges include volume limits, precision targeting, material dispensing and the general weaponization of lubricants into an artillery projectile.

Other technologies also are not practical for artillery delivery or pose legal or ethical issues that may prevent their coming to fruition in the US. These include super caustics and super acids that attack metal, rubber, glass, concrete or asphalt. Gel agents could cause fuel to gel. Contaminants could destroy the lubricating characteristics of engine oil. Super glue bombs combined with fibers could effectively seal doors to vehicles. Depolymerizers would attack plastic and rubber materials, such as tires. Embrittling agents could severely weaken metal structures.

By class, there are several technologies whose effects are not understood completely and (or) are unpredictable with the potential to cause unintended casualties.

Acoustics. Audible or sub-audible acoustics can have significant effects on individuals. Already in use are playing loud, irritating music or shrill tones for long periods of time.

The indiscriminate effects of this approach could be eliminated by a recent development, called a "sonic bullet." Precise targeting of the acoustic device allows high-intensity sound to be delivered at a distance while being inaudible to people standing nearby.

Another option, infrasound, that has frequencies below 20 Hz, cannot be detected by the human ear. But infrasound can resonate in human organs and cause pain and other serious effects.

The effects of acoustic devices are unpredictable and not completely understood. In addition, the delivery mechanism must include high-powered, large speakers or very precise targeting.

Entanglements. These are designed to mechanically constrain or terminate the mobility of vehicles or equipment. Typically involving some form of a net or wire, the deployed entanglement engages rotating or moving parts, such as wheels, drive shafts, radiator fans and tank treads that are difficult to remove.

Attaching metal cubes or wedges could jam tank treads or wheels. Sharpened metal "caltrop" stars caught by rotating engine parts could cut coolant lines and drive belts or perforate radiators.

Steel can entangle effectively but is heavy, bulky and unwieldy. Better options include high-strength synthetic fibers with strength-to-weight ratios nearly 10 times that of steel.

One option for engaging a passing vehicle could be small barbed caltrops that embed themselves in tires and interfere with the vehicle's operations. Another possibility might be pre-emplaced, target-activated dispensers. Camouflaging and precision targeting probably would be required.

Packaging and deployment challenges, along with volume limits, make this option difficult to pursue. The affected area would have to be rather small, and countermeasures or subsequent counter-deployment by the enemy are possible.

Thermites. These are highly exothermic powdered pyrophoric materials-- materials that give off heat during a chemical reaction. Composed of fuel and oxidizer components, reacting materials can reach nearly 3,000 degrees Celsius. Thermites can be designed to ignite under conditions of heat, shock or pressure. The energy liberated in the reaction is similar to high explosives but occurs at a much slower rate.

With an adequate delivery method, thermites could incapacitate vehicles and equipment. Relatively small amounts could burn through aircraft surfaces or vehicle air cleaners with the resultant slag causing the engine to seize. A larger quantity could bum a tire, melt a hole in an intake manifold or burrow holes into a power transformer.

Personnel injury and fire are potential unintended side effects.

Calmatives. A class of nonlethal technology that has been banned by the Department of Defense is calmatives. These are chemicals that to some degree have a calming effect on individuals. These effects range from mild relaxation to substantial lethargy to comatose incapacitation.

Although the technology is mature and the mechanisms are well understood, the upper bounds of the effects approaching lethality are often unclear. Administration of the appropriate dosage is a challenge. Calmatives often have less than a ten-fold difference between effective and lethal dosages.

The application of a calmative during the October 2002 siege of a theater in Moscow illustrates the problem. Russian Special Forces pumped a calmative gas into the theater held by terrorists in hopes of incapacitating the terrorists and, by co-exposure, their hostages. Due to an overdose or an excessively toxic mixture, more than 100 of the 850 hostages died from the effects of the gas.

Conclusion. As the battlefield grows increasingly complex, so will demands for nonlethal options. Artillery must be included in this evolutionary process. Thermobaric, high power microwave, smart dust and malodorants all seem worthy of near-term pursuit. Consideration also might be given to anti-optics (obscurants and light), engine technologies, irritants, carbon fibers and other sensors. With more detailed scrutiny and as technology and the political landscape evolve, these technologies may become more viable candidates.

In the contemporary operational environment, nonlethal artillery is relevant. Such capabilities will prove useful tools in the arsenal of future ground force commanders.

Kenneth L. Black is an Engineer in the Exploratory Systems Technologies Department at Sandia National Laboratories, Livermore, California. He is the Lead Engineer for the "Technology Options for Nonlethal Artillery," a study that is funded by the Armament Research, Development and Engineer Center (ARDEC), Picatinny Arsenal, New Jersey. Also in the Exploratory Systems Technologies Department, he is involved in defense- and energy-related feasibility studies, as well as global climate change research using high-altitude manned and unmanned aircraft. During most of the previous decade, he served as the Lead Propulsion System Engineer for the Operation and Deployment Experiments Simulator (ODES) Post-Boost Vehicle, an experimental payload deployment bus flown on the Strategic Defense Initiative (SDI)-related Strategic Target System Missile (STARS II). Prior to that, he was a Project Engineer for strategic defense payloads, fusion energy research and nuclear weapons.