Directed-Energy Weapons Promise 'Low Cost Per Kill'.

• Author: Erwin, Sandra I.

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 THEL.

"We always come up to the wire," said Bradshaw, during an...