Laser weapons for ground combat—ranging from air-defense
chemical lasers that destroy incoming rockets to smaller devices
that could zap enemy antennas—are the focus of several Defense
Department projects currently under way. If the technology pans
out, the U.S. Army, for example, would be able to equip its future
combat vehicles with all-electric laser guns.
Government and industry experts agreed that, even though there
are still technological and doctrinal hurdles to overcome, the use
of lasers in tactical weapon systems could bring about new types
of armaments that would be more accurate than explosive-based munitions
and much less costly.
The word laser is an acronym for “laser amplification by
stimulated emission of radiation.” Lasers are possible, because
of the way light interacts with electrons, which exist at different
energy levels. The first laser was invented more than 40 years ago.
Interest in directed-energy weapons has been growing within the
U.S. military services. The Air Force is developing a megawatt airborne
laser that would destroy intercontinental ballistic missiles. The
service, additionally, is in the early stages of developing a space-based
laser, also as an anti-ICBM weapon.
For ground combat, the U.S. Army is working on smaller lasers that
could defend against rockets, artillery, mortars, cruise missiles,
helicopters and unmanned aerial vehicles. The Army and the Israeli
government have spent about $200 million on a tactical high-energy
laser, a program that began about five years ago. The THEL is a
ground-based air-defense chemical laser designed to destroy Katyusha
and other short- range rockets. The beam’s heat destroys the
rocket by causing it to detonate.
THEL is a promising start, but it’s not what the U.S. Army
needs, because it’s not mobile, said Richard J. Bradshaw Jr.,
the service’s program manager for directed energy technology.
“Israel would be happy with a tractor-trailer size THEL,”
he said. But the United States wants a system that can fit on a
C-130 medium-lift aircraft. The current THEL weighs about 400,000
pounds, about 10 times the payload capacity of the C-130.
The Army is expected to complete a study next month on the development
of a mobile THEL. Funding could be a problem, given that all $200
million spent on THEL so far have been congressional add-ons.
For fiscal 2002, Congress is expected to allocate $30 million for
“We always come up to the wire,” said Bradshaw, during
an interview in Huntsville, Ala. Rather than rely on last-minute
add-ons, Bradshaw would like for the Army to provide a long-term
budget for the program. “We need to get it to the troops and
start testing the laser,” he said.
A lot of testing will be required before the Army could even consider
deploying laser weapons, Bradshaw explained. Commanders need to
be convinced that lasers are safe and that the operators are proficient,
he said. “The air commanders worry about the safety of a laser
pointing up into the sky,” Bradshaw said. Just like with any
other weapon, one problem in a combined arms environment is identifying
friend and foe. “With THEL, if there is a [friendly] aircraft
in its flight path, it creates a zone around it in the computer.
The beam cuts off and cuts on, on the other side.”
Bradshaw said the next step for THEL, in addition to making it
mobile, is to make it work with other systems, such as Patriot.
“We want to plug and play with operational Patriot systems,”
One advantage of killing enemy missiles with a laser is the relatively
low cost compared to kinetic-energy missiles. The Patriot’s
newest missile, the PAC-3, currently costs $3.8 million a piece.
A THEL shot is estimated to cost about $8,000.
The Holy Grail for the Army’s laser program, however, is
a 100-kilowatt solid-state laser. Solid-state are all-electric lasers.
Unlike chemical lasers, which require a chemical reaction, the solid-state
devices use electric power to convert the energy of the crystal
into laser power.
In the future, if the Army can develop a large solid-state laser,
the cost per kill would be measured in cents, not dollars, Bradshaw
said. A solid-state laser gun mounted on a hybrid-electric Humvee
truck would make the cost of operating that weapon essentially whatever
it costs to put diesel fuel in the truck engine. The advantages
of solid-state lasers for the Army would be significant, because
these systems would cost less and would be easier to maintain than
chemical lasers, he said. But the solid-state technology is not
mature, and there are technical problems to be solved, such as the
cooling of the laser materials, which tend to overheat. “These
things have a lot of complex piping,” said Bradshaw.
A solid-state laser that can be used as a tactical weapon may not
be available until 2015. The Army has developed a 10-kilowatt solid-state
laser, which is the largest of that kind ever built, said Bradshaw.
The Army’s solid-state laser program will receive about $90
million during the next five years, he said.
For the future combat system, the Army’s next-generation
tank, the goal is to have a 100-kilowatt, un-cooled, solid-state
laser, Bradshaw said. Until the FCS is developed, the preferred
vehicle to test a laser is a hybrid-electric Humvee, because it
provides on-board power generation.
In the commercial sector, TRW Inc. has built 4-5 kilowatt solid-state
lasers, for industrial machining applications. The company is a
prime contractor for military chemical-laser programs, including
THEL, the airborne laser and the space-based laser projects.
The Army contracted much of the development work on the 100-kilowatt
solid-state laser to the Lawrence Livermore National Laboratory
and to the Raytheon Company’s directed energy weapons division.
The company has produced more than 30,000 solid-state lasers for
weapon rangefinders and target designators, said Brad Sowers, head
of directed-energy weapons programs at Raytheon.
“We are looking at whether you can demonstrate a mobile directed-energy
weapon on a Humvee,” he said in an interview. Achieving that
goal, he said, could take several years.
“We have to demonstrate that we can scale the power to weapon-class
level and provide the thermal management—the cooling,”
he explained. It’s not as simple as cooling your car’s
engine, he said. “A lot of engineering needs to be done to
perfect the heat-exchange process and package it, so that it can
fit on a mobile vehicle.”
When it comes to introducing laser weapons into the battlefield,
the technology is only part of the equation, Bowers said. The safety
factor is no different than with other weapons, he said. “It’s
like a gun. If you point and shoot, it’ll damage. It has to
be handled like any other weapon that has destructive properties.
“As we produce these things, there is a lot to be learned
about how to handle the radiation coming out of the laser, how to
control the beam, how to protect the operators” from potentially
being blinded by a laser beam, he said.
Until the solid-state laser technology matures, the Army plans
to field small chemical lasers that would be mounted on C-130 aircraft
or helicopters. This technology would be used both by the Army and
by U.S. special operations forces to destroy ground targets tens
of kilometers away, said Bradshaw. There are ongoing tests to prove
the technology but, so far, “we have no implementation directive,”
The development of small chemical lasers falls under a program
called advanced tactical laser, which is expected to cost $180 million
through 2005, said Bradshaw. ATL uses a chemical oxygen iodine laser
(COIL) that generates up to 70 kilowatts of power.
The Marine Corps also is interested in ATL, because the technology
has applications in the Corps’ so-called non-lethal weapons
program. A small chemical laser beam would injure a human being,
but it also could, for example, destroy enemy antennas or disrupt
The prime contractor for the advanced tactical laser is the Boeing
Company’s Rocketdyne division. The ATL includes a laser, optics
and control systems enabling fire control systems on fixed and rotary-wing
aircraft to precisely direct laser fire on targets from 15 kilometers
The COIL in this program is a “sealed system,” explained
Don Slater, project manager at Boeing. A sealed system operates
with no exhaust, thus making it possible to have a laser weapon
in a small package, he said in an interview. With ATL, he said,
“We can melt through sheet metal at 1 mm per second.”
That means the beam could destroy structures that have a 1/8-inch
of sheet metal around. It could not penetrate ballistic armor, Slater
said. The targets, more likely, would be civilian vehicles and communications
antennas. The ATL is 15 feet long by 6 feet wide. If the Pentagon
decides to produce this laser, it potentially could be used against
low-flying cruise missiles, Slater said. The ATL concept provides
a “good geometry for attacking terrain-following missiles,”
he said. One advantage of laser weapons, he added, is that they
are remarkably precise. “You can do a visual identification
and there is no time lag from ID to shoot. So you have a tight control
over the situation.”