Navy May Need to Design Ships With Laser Guns in Mind

Unless the Navy starts building destroyers like the USS Spruance that can generate the power necessary to operate a laser gun, the Navy might never get its forthcoming focused-light weapons, according to a congressional study. Photo: U.S. Navy

After more than 20 years of research and development, the Navy's dreams of laser weapons are about to come true. But like the dog who chases the car and doesn't know what to do when he catches it, the Navy's thoroughly unprepared for its coming arsenal of focused-light weapons. A new congressional study warns that the Navy runs the risk of outfitting its surface ships with laser guns that their on-board power systems can't handle.

As Chris Partlow says to Marlo Stanfield in The Wire, this is one of those good problems.

Laser weaponry has progressed to the point where it's only a matter of time before they're disabling ships and burning missiles out of the sky. 'Over the next few years,' estimates a new Congressional Research Service report acquired by Danger Room, lasers 'capable of countering certain surface and air targets at ranges of about a mile could be made ready for installation on Navy surface ships.' Laser weapons with a 10-mile range aren't much farther away. If only the ships can handle them.

If the Navy hasn't come to grips with the imminence of its laser cannons, Congress needs to step in, the report suggests. One major issue: 'the potential implications of shipboard lasers for the design and acquisition of Navy ships, including the Flight III DDG-51 destroyer that the Navy wants to begin procuring in [fiscal year] 2016.' In plain English: Unless the Navy starts designing ships to carry laser weapons right from the shipyard, it may never get the futuristic weapons it wants.

The principle at work is pretty simple, from an engineering perspective, although it's largely been an obscure concern limited to Navy geeks. Unlike weapons that fire traditional ammunition, the Navy's coming inventory of laser weapons just need electrical power to fire. To get it, they've got to tap the on-board power generation systems of ships they'd be mounted on.

But the ships weren't designed with the expectation that they'd pack laser weapons. Their generators aren't built to create the kind of juice necessary to power laser guns without siphoning it away from their propulsion systems. It's a problem that gets worse when considering a laser gun's 'magazine' is as full or as empty as the fuel source it draws from. All that creates exactly the kind of choice the Navy never wants to confront: a choice between effective weapons and maneuverability. A wheezing, slow ship is a tempting target.

Current Navy shipbuilding plans hold shipbuilding basically steady at 285 ships for the next five years, after which the Navy plans to ramp up production in advance of about 70 ships aging out of service during the 2020s. The congressional study effectively asks if it's time to start baking the laser guns into the Navy's shipbuilding cake.

A laser is considered militarily practical if it can generate a 100 kilowatt beam ' which, as yet, no Navy laser under development can generate. The most powerful laser, the experimental Free Electron Laser, can potentially generate a megawatt's worth of pew-pew-pew. But the ships can barely handle that, at best.

'Some Navy ships might be able to support, under battle conditions, an SSL [solid-state laser] with a power somewhat above 100 kW,' the study finds. 'No existing Navy surface combatant designs have enough electrical power or cooling capacity to support an SSL with a power level well above 100 kW.' Worse yet for the Free Electron Laser, it's still so massive that it could only fit on an aircraft carrier or maybe a big-deck amphibious assault ship.

Accordingly, the study urges Congress to consider making the accommodation of laser guns standard for the next round of surface ships under construction ' much like how any decent car comes to the dealership already tricked out with power steering and other creature comforts. One option: 'design the new Flight III version of the DDG-51 destroyer, which the Navy wants to start procuring in [fiscal] 2016, with enough space, electrical power, and cooling capacity to support an SSL with a power level of 200 kW or 300 kW or more ' something that could require lengthening the DDG-51 hull, so as to provide room for laser equipment and additional electrical generating and cooling equipment.'

The report recommends the same power boosts for a potential new destroyer class if souping up the DDG-51 is unappealing. And it wants Congress to consider building the next big-deck amphibs and Ford-class aircraft carriers to generate 300 kilowatts or more.

Expensive? No doubt. Cheaper than building a ship and then retrofitting its power-generation systems to accommodate a laser gun? Almost definitely.

And the shipbuilding problems aren't the only obstacles Navy lasers still need to overcome. As the study points out, the Navy's lasers need to get much better at scaling up the power of their beams; managing all the heat they generate; improving 'target detection and tracking'; and integration into the rest of a ship's systems. These are 'not trivial' challenges, the study notes.

But they're also direct consequences of something the Navy may not have suspected it would ever have with laser technology ' success. Laser cannons are no longer science fiction. But the report points out an important distinction. Just because a weapon is increasingly realistic doesn't mean it's increasingly practical.