directed-energy weapons are mentioned, most people think of "death
rays" or Hollywood's latest science fiction movie. However,
directed-energy weapons (DEWs) are a reality, and several have
already been tested under battlefield conditions. They may begin to
appear on the battlefield within the next decade, bringing a
revolution in weapons and how war is waged.
DEWs are not the solution to all combat situations, these
technologies would provide the U.S. military with additional
flexibility in tailoring its response to different types of
threats. However, considerable work still needs to be done
before they can be deployed. These technologies need the full
support of the armed services, and the Department of Defense (DOD)
needs to generate clear guidelines for their use.
Pentagon believes that DEWs are legal under international law, but
human rights groups are arguing that DEWs could be used
inhumanely. Putting the proper protocols in place should mitigate
these concerns. While DEWs are not a panacea, the armed
services should fully support research and development of
these useful technologies.
Stone Age until the Middle Ages, a weapon's power was limited by
the strength of the man wielding it or, in the case of bows, by the
strength of material from which it was made. In the late Middle
Ages, a revolution in the weaponry occurred when chemical-powered
(gunpowder) weapons began to replace swords and bows. This
revolution changed the nature of warfare: not just tactics, but
also the usefulness of armor, castles, and then-popular
invention of gunpowder, a weapon's effectiveness has no longer
depended on the wielder's strength, but on the chemical energy of
the propellant or explosive. While centuries of technological
advances have improved the power of these materials, the basic
operating principle of chemical-powered weapons ultimately remains
the same. Modern battlefield weapons are the descendents of
muskets and cannon.
revolution in weaponry is currently underway, with directed-energy
weapons on the cusp of replacing chemical-powered weapons on the
battlefield. DEWs use the electromagnetic spectrum (light and radio
energy) to attack pinpoint targets at the speed of light. They
are well-suited to defending against threats such as missiles
and artillery shells, which DEWs can shoot down in mid-flight. In
addition, controllers can vary the strength of the energy put on a
target, unlike a bullet or exploding bomb, allowing for nonlethal
Beginning of Directed-Energy Weapons
Allies and the Axis powers conducted basic research and studies
into primitive directed-energy weapons before World War II.
However, British scientists calculated that the electronic
systems of the time could not generate the power
necessary for a "death ray," and research was redirected into
early radar detection systems.
the Cold War, the U.S. and the Soviet Union studied the possibility
of creating particle-beam weapons, which fire streams of electrons,
protons, neutrons, or even neutral hydrogen atoms. The kinetic
energy imparted by a particle stream destroys the target by heating
the target's atoms to the point that the material literally
explodes. These weapons were considered for both land and
space-based systems. However, because beam strength degrades
rapidly as the particles react with the atoms in the atmosphere, it
requires an enormous power plant to generate a weapons-grade beam.
The countries abandoned particle-beam weapon research as
Einstein described the theoretical underpinnings of lasers in
1917. However, the first working laser was not built until
1960, opening an entirely new avenue of directed-energy research.
Lasers produce narrow, single-frequency (i.e., single-color),
coherent beams of light that are much more powerful than ordinary
light can be produced by a number of different methods,
ranging from rods of chemically doped glass to energetic chemical
reactions to semiconductors. One of the most promising laser
devices is the free-electron laser. This laser uses rings of
magnetically confined electrons whirling at the speed of light to
produce laser beams that can be tuned up and down the
electromagnetic spectrum from microwaves to ultraviolet
produce either continuous beams or short, intense pulses of light
in every spectrum from infrared to ultraviolet. X-ray lasers may be
possible in the not too distant future. The power output necessary
for a weapons-grade laser ranges from 10 kilowatts to 1 megawatt.
When a laser beam strikes a target, the energy from the photons in
the beam heats the target to the point of combustion or
melting. Because the laser energy travels at the speed of light,
lasers are particularly well-suited for use against moving targets
such as rockets, missiles, and artillery
problem that affects laser beam strength is a phenomenon known as
"blooming," which occurs when the laser beam heats the atmosphere
through which it is passing, turning the air into plasma. This
causes the beam to lose focus, dissipating its power. However, a
variety of optical methods can be used to correct for blooming.
Laser beams also lose energy through absorption or scattering if
fired through dust, smoke, or rain.
number of "shots" a laser weapon can produce is limited only
by its power supply. Depending on the type of laser, this
means that the weapon can have an almost "endless magazine" of
laser bursts. In addition, a laser shot (including the cost of
producing the energy) is much cheaper than a shot from a
chemical-powered weapon system. For example, when deployed, the
anti-ballistic missile Airborne Laser will cost approximately
$1,000 per shot, while each Patriot missile currently costs
$2 million to $3 million.
they were invented several decades ago, lasers are the most mature
of the DEW technologies. Laser dazzlers-devices that use laser
light to temporarily blind sensors, optics, and personnel- are
already available for law enforcement and military use. In
1995, the Chinese military marketed the ZM-87 laser interference
device, a tripod-mounted battlefield laser dazzler designed to
blind enemy soldiers and optics temporarily. In March 2003, North
Korea may have used a ZM-87 to "paint" two U.S. Apache helicopters
patrolling the Demilitarized Zone.
U.S. laser weapons systems closest to actual deployment are the
Tactical High-Energy Laser (THEL) and the Airborne Laser
of the THEL began in 1996 as a joint program between the United
States and Israel to develop a laser system capable of shooting
down Katyusha rockets, artillery, and mortar shells. The THEL
system uses radar to detect and track incoming targets. This
information is then transferred to an optical tracking system,
which refines the target tracking and positions the beam director.
The deuterium fluoride chemical laser fires, hitting the
rocket or shell and causing it to explode far short of its intended
2004, the THEL system shot down multiple mortar rounds during
testing. However, the Army felt the fixed-base laser system was too
large and cut funding for the program after the demonstration
phase. Research was also conducted on a mobile version of the THEL
called the MTEL.
is a system that uses a megawatt chemical laser mounted on a
modified Boeing 747 to shoot down theater ballistic missiles. The
system consists of several modules: an infrared detection system to
detect the missile's launch; the Tracking Illumination Laser
(TILL); the Beacon Illuminator Laser (BILL); and the Chemical
Oxygen Iodine Laser (COIL).
tracked by the TILL, the BILL measures the atmospheric distortion
between the COIL and the missile. These data are then passed on to
the mirror system, which makes appropriate corrections so that,
when the COIL fires, maximum energy is transmitted to the target.
The skin of the missile heats up, melts, and deforms, and the
target breaks up in midair.
megawatt-class laser was tested at full power in early 2006. The
Beacon Illuminator Laser system, which measures and corrects
for atmospheric distortion, has also been shipped to Boeing for
testing. A complete prototype ABL weapons system
will be assembled in 2006.
project is the Advanced Tactical Laser (ATL) system, which uses a
less powerful version of the ABL's COIL laser, instead of missiles,
to attack ground targets. The laser is being built and will be
tested in mid-2006. Boeing has received a C-130H transport aircraft
from the Air Force and is modifying it for installation of the
laser system. The full system will be fitted to the aircraft by
2007 and test-fired against ground targets.
shortcoming of laser weapons is that their beams travel only in
straight lines, which means they have no indirect-fire mode and
cannot shoot beyond the system's visual horizon. The DOD Office of
Force Transformation (OFT), in conjunction with the Air Force
Research Laboratory, is developing the Tactical Relay Mirror System
(TRMS), which would use a mirror system mounted on an aerostat or
UAV (unmanned aerial vehicle) to redirect the beams from laser
weapons such as the ATL and ABL. Design specifications are already
Microwave Weapons Work
off as impractical during World War II, technological advances have
now made microwave weapons feasible. However, current research
focuses on using them as a means of nonlethal area defense and as
anti-electronic weapons rather than as "death rays."
microwave (HPM) weapons work by producing either beams or short
bursts of high-frequency radio energy. Similar in principle to the
microwave oven, the weapons produce energies in the megawatt
range. When the microwave energy encounters
unshielded wires or electronic components, it induces a
current in them, which causes the equipment to malfunction. At
higher energy levels, the microwaves can permanently "burn out"
equipment, much as a close lightning strike could.
and modern electronics are particularly susceptible to HPM
attacks. Electronic devices can be shielded by putting conductive
metal cages around them; however, enough microwave energy may
still get through the shielding to damage the device.
short, intense bursts of energy produced by HPM devices damage
equipment without injuring personnel. Mounted on properly shielded
aircraft or ships, or dropped in single-use "e-bombs," HPM weapons
could destroy enemy radars, anti-aircraft installations, and
communications and computer networks and even defend against
incoming anti-aircraft and anti-ship missiles. With the
ever-increasing use of electronics in weapons systems, HPM devices
could have a devastating but nonlethal effect on the
weapon technology is based on the same technology as radar devices,
which already have a long history of research and development.
However, no military has yet openly deployed HPM weapons.
Current HPM research focuses on pulsed power devices, which create
intense, ultrashort bursts of electrical energy and would be used
to power the microwave generator of an HPM weapon. The Air Force
Research Lab's Propulsion Directorate has studied using generators
that use high-temperature superconducting wire and high-voltage
power source, well-suited to one-time use in an e-bomb, is the
Explosively Pumped Flux Compression Generator (EPFCG). The EPFCG
uses chemical explosives to compress an electrically charged
coil. This destroys the device but produces electrical pulses
in the terawatt range-the equivalent of 10 to 1,000 lightning
with a microwave generator, an EPFCG could produce an ultrashort,
intense microwave burst. Depending on factors such as burst height,
microwave frequency, and the shielding around the target
electronics, such an e-bomb could have an effective range of
several hundred meters.
of HPM devices can affect the human body. Millimeter waveband
energy can penetrate human skin to a very shallow depth, heating
the tissue below. This produces a burning pain without actually
damaging the tissue. The pain forces the person to flee the area.
This type of weapon shows great potential as a riot-control device
or area-denial system.
Active Denial System (ADS) is a nonlethal anti-personnel DEW that
uses millimeter-wavelength beams to create a painful sensation
in an individual without causing actual injury. It is
relatively close to deployment. The system generates a focused
beam of energy at the frequency of 95 gigahertz. These waves
penetrate only a few millimeters into the skin and cause the
sensation of heat. The sensation increases in intensity until the
affected individual moves out of the beam or it is shut off. There
is no injury to the target individual.
demonstration system was tested at Kirtland Air Force Base in 2000.
A year later, testing showed that the ADS could produce effects at
ranges beyond current small-arms range. A prototype ADS system
mounted on a Humvee went into testing in August 2005.
Future of DEW
research will seek to increase the power and decrease the size of
DEW systems. As they become smaller, DEW weapons will first be
vehicle-mounted and then possibly man-portable. The death ray
of science fiction may in fact become a reality in the not too
are becoming smaller and more powerful. For example, a recent test
of a solid-state laser by Northrop Grumman produced a continuous
27-kilowatt beam that lasted just under six minutes.
possible future development is the electrolaser. Electrolasers make
use of laser bloom, a normally undesired effect. In an
electrolaser, twin laser beams create an ionized channel inside the
atmosphere, which conducts electricity. A high-voltage
electrical charge is then fed into one of the laser beams, striking
the target. The electrical shock is enough to stun personnel,
detonate improvised explosive devices, or destroy electronic
in energy-generating systems may also make particle-beam weapons
feasible. Particle beams would have tremendous power as weapons.
Like lasers, particle beams travel at the speed of light, but
unlike lasers, the particles in a particle beam have mass, giving
the beam tremendous kinetic energy.
point in the future, entire military units may be armed with only
DEWs. A mechanized unit advancing through a town, protected by an
anti-artillery and anti-missile laser shield, clearing the
surrounding buildings of snipers and enemy troops with an active
denial system, and using electrolasers to stun them before
taking them prisoner, all while using HPM weapons to render the
enemy's communications useless, would be a powerful military
and Legal Implications for DEWs
designed to cause undue suffering are banned under the Geneva
Convention, and human rights groups argue that directed-energy
weapons raise a host of new legal and moral concerns that do not
apply to previous generations of conventional weapons. For example,
while the Chinese ZM-87 laser interference device is technically a
laser dazzler, it can permanently damage the human eye at a
distance of two to three kilometers. Would the permanent
blinding of a soldier struck by a ZM-87's laser beam be considered
intentional or accidental? Does the mere use of a weapon that
can cause permanent blindness constitute inflicting undue
suffering? The humanitarian community is also concerned about the
long-term biological effects of DEWs (microwaves in particular) and
their possible use against civilian targets.
a stronger counterargument is that directed-energy weapons,
especially lasers, are more humane than conventional weapons
because they can strike pinpoint targets, thus causing less
collateral damage. A laser weapon could target not only a single
vehicle in a convoy, but also a specific spot on that vehicle
(e.g., the engine) and disable it without injuring the passengers.
Furthermore, the power of lasers and microwave weapons has
decreased, allowing for nonlethal uses.
technology is changing faster than international laws and
treaties can adapt. General DOD policy is that directed-energy
weapons can be used legitimately on the battlefield. As with all
new weapons, the DOD General Counsel reviews each DEW for
compliance with international and U.S. laws before the Pentagon is
allowed to field it. Most DEWs are not yet far enough along in
development and thus have not received this final stamp of
Pentagon addresses these issues, it should do so in the same way
that it would for any other category of weapon that it has
reviewed. While some uses may be illegal (e.g., targeting an
unarmed civilian who in no way poses a threat), other uses are just
as assuredly legal and legitimate.
the Research and Deployment Bottlenecks
directed-energy research is advancing, inadequate funding is
hindering more rapid development and deployment of these
technologies. The military has rhetorically embraced the wonders of
DEWs, but it has not always opened its wallet to fund the
support for a program is often best measured by the resources
that an organization is willing to devote to it. For instance,
the Active Denial System was not ready for deployment when the
United States invaded Iraq, in part because the money was not
there. The Defense Department and Congress should start to fund
promising and proven DEW technology so that promising weapon
systems can move from the lab to the battlefield where they can
help military personnel.
technology and its enabling infrastructure have matured to the
point that DEWs can begin moving from the lab to the battlefield.
While directed-energy technology is not the panacea for all
situations that its most ardent advocates claim, it can give the
U.S. military flexibility in tailoring its responses (e.g., lethal
or nonlethal) to different types of targets (humans or
needs to be done before DEWs are deployed. The armed services need
to move from just saying that DEWs are a good idea to fully
supporting their development. The Defense Department
needs to establish clear guidelines for using the technology. The
speed, ultraprecision, and nonlethal capabilities of
directed-energy weapons are all good reasons why the United States
should continue to research, develop, and, where appropriate,
field these technologies.
Kochems is a Policy Analyst for National Security in the Douglas
and Sarah Allison Center for Foreign Policy Studies, a division of
the Kathryn and Shelby Cullom Davis Institute for International
Studies, at The Heritage Foundation. Andrew Gudgel, a former
Army Warrant Officer, is currently a freelance
24, 2004, the Tactical High Energy Laser (THEL) system destroyed a
salvo of mortar rounds in midair during a test. "Mobile/Tactical
High Energy Laser (M-THEL) Technology Demonstration Program,"
Defense Update, at
(March 10, 2006).
Fisher, A Race on the Edge of Time: Radar-The Decisive Weapon of
WWII (New York: McGraw-Hill, 1988), pp. 15-31.
M. Roberds, Ph.D., "Introducing the Particle-Beam Weapon," Air
University Review, July-August 1984, at
(March 15, 2006).
ed., s.v. "laser."
Chapman, "The Airborne Laser," Air Force Magazine, Vol. 79,
No. 1 (January 1996), at
(March 15, 2006).
"Patriot Advanced Capability-3 (PAC-3)," at
(March 15, 2006).
Gertz, "N. Korea Fired Laser at Troops," The Washington
Times, May 13, 2003, at
(March 15, 2006).
High Energy Laser (M-THEL) Technology Demonstration
release, "Airborne Laser Progress Continues as Northrop Grumman
Runs Full-Power COIL Tests, Delivers Beacon Illuminator
Laser," Northrop Grumman Corporation, January 4, 2006, at
(March 15, 2006).
Media, "ABL YAL 1A Airborne Laser, USA," at (March
release, "Boeing Receives Aircraft for Laser Gunship Program,"
Boeing, January 23, 2006, at
(March 15, 2006).
Craig Hughes, Office of Force Transformation, U.S. Department of
Defense, "Re-directed Energy: the Tactical Relay Mirror System,"
presentation at The Heritage Foundation, Washington, D.C., February
Force Research Laboratory, "High-Power Microwaves," fact sheet,
September 2002, at (March
Stephen Adams, "Electrical Power and Thermal Management for
Airborne Directed Energy Weapons," U.S. Air Force Research
Laboratory, September 2001, at
(March 15, 2006).
Kopp, "The Electromagnetic Bomb-A Weapon of Electrical Mass
(March 15, 2006).
"High Power Microwave (HPM)/E-Bomb," at
(March 15, 2006).
Force Research Laboratory, "Active Denial System," fact sheet,
September 2005, at
(March 15, 2006).
release, "Northrop Grumman Surpasses Power, Run-Time Requirements
of Joint High Power Solid-State Laser Program for Military
Use," Northrop Grumman Corporation, November 9, 2005, at
(March 15, 2006).
North Industries Corporation, "ZM-87 Portable Laser Disturber Fact
Sheet," quoted in Human Rights Watch, "Blinding Laser Weapons:
The Need to Ban a Cruel and Inhumane Weapon," September 1995, at
Weapons: Come Fry with Me," The Economist, January 30, 2003,
(March 15, 2006).
Ruppe, "Directed-Energy Weapons: Possible U.S. Use Against Iraq
Could Threaten International Regimes," Global Security
(March 15, 2006).