One of the first tasks the Navy expects to assign its forthcoming arsenal of laser guns: shooting down drones that menace its ships.

The Navy is confident that laser cannons will move out of science fiction and onto the decks of its surface ships by the end of the decade. Its futurists at the Office of Naval Research still have visions of scalable laser blasts that can fry an incoming missile at the rate of 20 feet of steel per second. But now that laser guns are approaching reality, Pentagon officials are starting to consider the practicalities of what they'll be used for, and they're not thinking missiles – yet. Among their initial missions will be the relatively easier task of tracking and destroying unmanned aerial vehicles, or UAVs, that fly too close to Navy ships.

Attacking drones is "a near-term application for the type of lasers we're talking about," says David Stoudt, a Pentagon policy official. "If you've got a UAV coming at a ship," he explains, "maybe you use the laser for UAVs and keep your missiles for higher-end threats."

Stoudt, the Pentagon policy office's senior director for naval capabilities and readiness, chairs a relatively new steering group inside the Navy and Marine Corps that's thinking through exactly how they'll use this new "directed energy" technology – i.e., lasers and other ray guns. It's got some bureaucratic heft to it: About 20 to 25 admirals and generals sit on it; and below them, another 150 to 175 captains and other officers of lower rank, from across the fleet and the Corps, comprise a working group that fills in some of the detail.

"What it gets down to is the topic of lethality," Stoudt explains in an interview in his Pentagon office. "What are you going to try to shoot with this laser system? Ultimately, what kind of power density does it require on the target? What is the tactical scenario that you're going to be in?" Pointing your index finger and going pew-pew-pew, it turns out, is not an answer.

Lasers have been promised – and promised, and promised – as a holy-grail weapon for decades, with little to show for it outside a laboratory. Congress is skeptical, particularly about the most advanced laser systems, and is starting to warn the Navy that it needs to design newer destroyers with sufficient power generation to fill the focused-light magazine of its lasers without draining juice from a ship's propulsion systems. Nor do sailors think of lasers as combat weapons, Stoudt says, and so his working group pulls them together to teach them "you can do this, you can't do that." The easiest way to snuff out the laser guns right when they finally look like realistic weapons is to overpromise on what they can do, and under-deliver.

Which makes shooting down drones seem like a risky choice to lead off with – exactly the kind of thing that, should it fail, would make the Navy's laser program look like a very expensive, nerdy amateur hour. Stoudt is undeterred. He's convinced that the solid-state lasers that the Navy is looking to use in its first wave of laser weaponry can handle the challenge, even though testing has yet to generate a beam of 100 kilowatts of energy, which the Office of Naval Research's futurists estimate is desirable for weaponization.

Stoudt points to tests the Navy's conducted at its surface-warfare proving ground in Dahlgren, Virginia that have pit lasers against drones. Neither he nor Dahlgren officials nor the Navy's aviation command would say much about the tests. ("We've had multiple UAV engagements that were successful," is about as much as Stoudt will elaborate.) But some information on them has become public.

In 2009, an Air Force laser weapon shot down five robotic planes with a beam of a mere 2.5 kilowatt intensity during a California test. The following year, a Phalanx gun tricked out with a laser beam "successfully tracked, engaged, and destroyed" a drone in flight over the sea, the Navy's sea-systems command boasted.

And while it's not a drone test, it's worth noting that the Maritime Laser Demonstrator, a decommissioned destroyer used to test laser weapons, last year blasted away the outboard motor of a moving boat in California waters from a mile's distance in choppy waters. That solid-state laser used a beam of merely 15 kilowatts – which the proud director of the Office of Naval Research noted at the time, "can be operated in existing power levels and cooling levels on ships today."

Blasting drones is just one of the initial tasks Stoudt's group envisions for first-wave lasers. "Early applications will focus on supporting forward deployed forces to defeat Improvised Explosive Devices (IEDs); artillery, mortars, and rockets; intelligence surveillance and reconnaissance systems; fast-attack craft; fixed and rotary-wing aviation; and subsonic anti-ship cruise missiles," reads a passage from a document his working group finalized and quietly circulated in January, called A Directed Energy Vision for U.S. Naval Forces, and acquired by Danger Room.

That's not going to mean that the first wave of Navy lasers will blast insurgent bombs out of the ground. Stoudt and his team are talking more about using the laser's capabilities for identifying all this stuff, and then aiding existing, conventional weaponry in attacking it. "Ultimately, this laser will have an excellent telescope and great sensors associated with it," Stoudt says, "and what you can do with that in terms of combat ID is really rather remarkable."

In other words, it's a mistake to think of laser guns as taking the place of traditional weapons, Starship Troopers style. They're going to work in tandem, especially in their early phases. The old school weapons will still take on the bigger adversaries, like enemy ships. But for smaller attackers, there may be a new way soon to ward them off – one that relies on focused light, not hardened metal.