James Holmes

Lasers! What Are They Good For?

Lasers won’t solve all the problems facing naval weaponeers, but they’ll help address quite a few of them.

Lasers! What Are They Good For?
Credit: Wikimedia Commons

So the Naval Diplomat went on National Public Radio out in Los Angeles yesterday — via phone, alas, not onsite — to discuss the “laser gun” mounted aboard USNS Ponce, a U.S. Navy amphibious transport-cum-afloat forward staging base (AFSB). Occasioning NPR’s interest: this week the navy leadership has certified the old amphib’s 30 kW laser weapon system (LaWS) for combat use. Even while it undergoes testing, LaWS will provide some defense against lower-end threats from the likes of Iran and ISIS.

Why the hurry? Well, the AFSB concept is a nifty one. It envisions positioning a mothership in or near embattled zones as a floating airbase and hub for special forces, and to experiment with off-the-wall joint-service tactics, techniques, and procedures. From there it can radiate military power inland or along the coastal periphery. In navy parlance, Ponce is an “interim” AFSB, a gapfiller until purpose-built vessels known as mobile landing platforms (MLP) — modified commercial tankers — are ready to take her place.

Trouble is, a more or less stationary asset like an AFSB or MLP makes a nice target for adversaries intent on foiling American operations in their environs. Ponce is not a high-value U.S. Navy unit like an aircraft carrier, entitled to an entourage of destroyers and cruisers to shield her from attack. She’s an elderly, lumbering steamship that loiters within reach of shore-based missiles, aircraft, and drones, not to mention speedboats and other small surface craft. And she’s forward-deployed to the Persian Gulf region, whose denizens operate access-denial platforms in large numbers.

Hence the need for defensive firepower. An individual speedboat, or drone, or warplane is largely a nuisance. Swarms of such nuisances converging on the same place at the same time add up to a deadly menace — even to warships far more capable than an amphib. Ponce‘s laser, reports the Office of Naval Research, has proved effective against such threats as small boats and unmanned aircraft. Hence the decision to fast-track the LaWS. The weapon’s out there; why not use it in times of extreme peril? It can’t hurt.

The NPR hosts were interested in more than the official hype, though. Yes, you can fire a laser for pennies (discounting the cost of infrastructure such as generators, auxiliary gear like coolant pumps, and the device itself). That’s a far cry from missile engagements that cost the navy hundreds of thousands of dollars per round. And in all likelihood, if the incoming threat is an anti-ship cruise missile, a ship will expend multiple rounds per engagement. Fending off one assault could cost upwards of a million bucks. Virtually unlimited ammunition on the cheap constitutes a mighty good deal.

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Effective laser defenses, moreover, would ameliorate the opportunity costs of stocking defensive missiles. There’s a zero-sum relationship between defensive and offensive weaponry on board surface combatants. You only have a finite number of vertical-launch cells. That means every “bird” meant for air or missile defense is a bird not used to pummel enemy warships or land targets. Defense, then, comes at the expense of offense.

If lasers could mount a foolproof defense by themselves, though, every vertical launch cell on board a destroyer or cruiser could pack land-attack or anti-ship missiles for offensive missions. That would magnify the fleet’s striking power at a stroke. It would also diminish the need to provide escorts for fleet air defense. If high-value units can fight off planes and missiles, escorts can concentrate on the equally onerous chore of finding, tracking, and sinking submarines. In short, the new technology could liberate naval commanders from dilemmas that have bedeviled them for decades.

But let’s not give in entirely to the hooplah. Yet. For one thing, the laser isn’t yet even a “program of record,” an official requirement vetted by budgeteers in Washington. The navy expects to make it a program of record in fiscal year 2018 or thereabouts and hopes to declare initial operating capability (IOC) for a shipboard laser in fiscal 2020 or 2021. IOC means deploying a system while still working out the kinks. Full deployment presumably remains a decade off.

Between now and then, naval weaponeers plan to experiment with far higher-power lasers than the one installed in Ponce — to the tune of five times the LaWS’s output — before making them standard armament. That means engineering challenges — generating enough electrical power and keeping the weapon cool, to name two — still lie in store. By no means is fielding this exotic hardware a done deal. Nor is there any guarantee that the project will stay on schedule. Timelines habitually slip when developing complex weaponry. (See Ship, Littoral Combat.)

Apart from budgets and mechanical challenges, some limits are intrinsic to laser weapons. To start with the most straightforward, light travels in straight lines. This is a line-of-sight weapon. Consequently, its range against surface shipping is limited by the visible horizon. If Ponce‘s laser were mounted, say, 50 feet above sea level, it could engage enemy small craft about 8.5 miles distant. That’s knife-fight range in surface warfare. Or, atmospheric conditions such as humidity affect light propagation, potentially hampering combat use of the new system. The tactical environment is inescapable. And as with all weapons, countermeasures are available. Airframes and hulls can be plated or coated to resist or shed heat. Smoke and other “obscurants” scatter light while keeping defenders from sighting their assailants.

And so forth. Bottom line, this is a promising technology that may eventually let surface combatants ride out air and missile attack while amplifying their combat punch. But we’re not there yet, and it’s conceivable that more battleworthy descendants of LaWS will never fulfill their promise. That’s the nature of scientific-technical enterprises. And even if high-powered shipboard lasers do live up to their billing, foemen will still cast their vote against the U.S. Navy’s efficacy as a fighting force. They will formulate defensive measures and workarounds of their own. The cycle of military one-upsmanship will continue. Challenge, reply.

The strategist Mr. Spock, no stranger to directed-energy cannon he, once observed that military secrets — and the military advantages that derive from them — are perishable in the extreme. Quite so.

Fascinating, captain.