Many observers argue that laser weapons should stick to fighting missiles, rockets and aircraft because these targets tend to destruct or crash when even a small part is damaged. Trucks and tanks are another matter altogether, says John Pike, director of Alexandria, VA-based defense-policy think tank Globalsecurity.org. “That’s why bullets and shells are still popular-there’s no way a laser is going to deposit more energy on a target than would have been created by an equivalent amount of chemical explosive.”
In that view, killing a tank would be a stretch, given its 15-centimeter-thick armor plating. But the new idea is to disable, not destroy-and tanks have a high-tech Achilles’ heel: their dependence on electronic communications and sensors to know what’s going on. Melting a tank’s antennas would be easy for a 300-kilowatt laser. Explains Colonel Mark Stephen, who helps manage the air force’s laser weapons programs, “You can destroy or at least degrade a target without blowing it to bits.” What’s more, the loss of communications or other electronics systems would likely confuse the tank crew-and that could be all it takes to destroy the tank with conventional weapons.
With the ability to place a 10-centimeter-wide beam with the heating power of a blowtorch on distant targets for up to 100 shots, the Advanced Tactical Laser could wreak havoc on far more than tanks. One analysis noted that from seven kilometers away the system could also melt 11 antennas, blow out 32 truck tires and disable a mix of a dozen mortars, rocket launchers and machine guns before having to refuel. For all its potential, however, this weapon faces some unique headaches. Ground vehicles bounce and vibrate more heavily than aircraft, for starters, and if the laser is ever deployed on such vehicles it will require computer-
controlled shock absorbers. In addition, intense ground battles tend to produce laser-blocking smoke and dust. And getting chemical fuel to a remote, hotly contested battleground could be difficult.
A research effort earmarked for $100 million in funding starting in 2003 is looking to solve the fueling problem. The goal is to replace the current chemically fueled laser with a solid-state weapon that gets its energy from an electric current directed into an yttrium-aluminum-garnet compound, doped with neodymium. Laboratory versions of solid-state lasers currently put out a meager 10 kilowatts of power. But Bradshaw believes that figure will be upped to 100 kilowatts-enough to serve as a weapon.
Even farther down the road, researchers hope to replace the yttrium-aluminum-garnet compound with super-energy-efficient fiber-optic lasers like those already used in some telecommunications applications. A fiber-optic laser might fit in a Humvee and, because it would be electrically powered, could run off of the vehicle’s generators, shedding the burden of resupplying special fuel. “You’d have to haul around some additional diesel fuel, but that’s not much of a price to pay for being able to electrically generate your bullets right there in the field,” says Bradshaw.