Airport Defense: Lasers, Microwaves

Cheap, low-tech, easy-to-use, and utterly lethal, shoulder-fired missiles have become a terrorist weapon of choice, killing more than 640 people in 35 attacks on civilian jets. And so far, countermeasures have proven too finicky and too expensive to widely deploy. So the Department of Homeland Security is trying out instead a pair of new defenses, seemingly straight of science fiction: laser guns and microwave blasters.
The Department will spend $4.1 million to test out Raytheon's "Vigilant Eagle" system, which relies a series of microwave pulses to throw off a missile's guidance package. A series of passive infrared trackers, installed around an airport, would look out for missile exhaust. When these sensors detect a launch, data about the missile's trajectory is sent to a control center, which in turn tells a billboard-size microwave array where to blast.
How exactly this is done without disrupting a plane's avionics system has never been fully explained to me. Which may be why DHS is also sinking nearly $2 million into a study of Northrop Grumman's laser-based, "SkyGuard" defense, as well.
The system is a modification of the company's Tactical High Energy Laser, which successfully blasted dozens of Katyusha rockets and mortars out of the air during military testing. The laser, powered by vats of toxic chemicals, was considered too cumbersome for battlefield use. A permanent set-up an airport might be a different story, however.
DHS has spent nearly four years and $239 million to adapt the military's series of countermeasures to civilian jets. But most commercial carriers have been unwilling to pay for the systems, which could cost $50 billion over ten years to install and maintain. So far, Fedex is the only big flier to invest heavily in the defenses, agreeing to outfit 11 of its planes with the countermeasures.
Ground-based systems -- even ones based on ray guns -- might prove more palatable to the airline industry. Sure, the technology is less proven than the jet-based defenses. But eventually, the microwave and laser blasters could prove "more reliable," Daniel Goure, vice president of the Lexington Institute, tells Bloomberg News. "It is easier to be on the ground where you can have an infinite power supply. Aircraft are only vulnerable below a certain altitude, when they are taking off and landing. For most airports you can place them on towers where you can cover landing and takeoff routes."
Raytheon and Northrop have 18 months to prove their futuristic systems are ready to handle the job.
UPDATE 4:18 PM: In case you're wondering -- no, this is not the 300-oven death ray.
(Big ups: CP)