The Pentagon wants laser weapons badly. Their first foray into the realm of ray guns was the impressive-but-impractical Airborne Laser Testbed, a Boeing 747 with a giant laser mounted on its nose. That project was scrapped, but the Defense Advanced Research Projects Agency (DARPA) is moving ahead with two new plans to make laser weaponry a reality.
The High Energy Liquid Laser Area Defense System (HELLADS) is DARPA's answer to increasingly sophisticated surface-to-air threats. These liquid-cooled lasers would be mounted on turrets on combat airplanes to shoot down incoming rockets or missiles.
DARPA's description of HELLADS also mentions "additional capability for offensive missions as well -- adding precise targeting with low probability of collateral damage."
The goal of the project is to design a 150-kilowatt system small enough to fit on fighter jets and bombers. DARPA says that HELLADS will be "ten times smaller and lighter than current lasers of similar power."
The second project DARPA is working on is Aero-Adaptive/Aero-Optic Beam Control (ABC). This system is more defensive than HELLADS. The ABC lasers are designed to shoot backwards -- the direction that most oncoming missiles come from. The difficulty with this is that the turbulence generated by a jet engine can de-focus laser beams and makes targeting a challenge. Like HELLADS, the laser would be mounted on a turret.
Both projects are much further along than one might think. HELLADS will see its first real-world, airborne tests next year. ABC has passed wind tunnel tests and Lockheed Martin has a 30-month contract to make the system a reality.