Lockheed Martin Space Systems Co. said Thursday that it has signed a deal with General Atomics, a San Diego defense contractor, to help develop a tactical laser weapon that could defend a population center, a border or troops against artillery, mortar, rockets or missiles ... General Atomics will actually build the laser, while Lockheed Martin, which employs 8,500 people in Sunnyvale, will develop the system's ability to pinpoint and track a target.MILITARY LASER! ROWR! Shit, maybe if we actually build a couple of no-shit seen-outside-concept-laboratories military lasers, space operas will quit with the stupid ass "bing! bing! zap! zoop!" noises when energy weapons are fired?
Anyway, this DARPA project is scheduled for completion in 2009, and has a design spec of 5 kilograms per kilowatt. If that doesn't mean anything to you, here's an interesting analogy: a 2002 Camaro Z28 SS with the big 5.7L motor in it develops roughly 325hp and weighs about 3,574 pounds. If we do a little metric conversion, that's about 257KW and 1,621 KG - a power to weight ratio of 6.3 kilograms per kilowatt.
So it's not completely unscientific to imagine that a laser the size (well, mass) of a Camaro would deliver roughly as much energy to a target as... the Camaro itself would, if it had a needle-sharp lance welded to the front bumper, and a homicidal maniac behind the wheel gleefully stomping on the gas.
For those of you who care enough to read this but not enough to have thought about the military tactical implications... practical lightweight lasers will change warfare DRASTICALLY. Very drastically. Assuming this thing gets off the drawing board and into practical deployment, expect radical changes in the viability of (complex) missiles as payload delivery systems, truly BRUTAL anti-personnel capabilities (in desert conditions), and... a plethora of line-of-sight-disruption systems such as aerosol mists, high-albedo chaff, and more. Also expect weather to play a TREMENDOUS role in attack schedules when either side possesses laser weapons - they aren't gonna be worth a shit in the rain. (At least as compared to their low-humidity performance - how well they do in less-ideal optical conditions will largely depend on how high frequency they are; X-ray or gamma-ray lasers would be ideal for dealing with adverse conditions.)
DON'T expect much in the way of anti-armor out of laser weapons, particularly first-generation laser weapons - it's going to be a long time, if ever, before a pure energy weapon can pack anything like the anti-armor punch of a HEAT or DE sabot round. Honestly, it'll be a long time before a beam weapon can even produce the same physical punch as a standard 20mm shell, much less anything fancy... but what punch they do produce, when in the correct optical conditions to produce it, is going to be utterly line-of-sight instantaneous and INSANELY fast in terms of tracking compared to conventional weaponry.