Lasers Could Become Cost Effective Missile Defense Weapons
The U.S. military invests more money than any other country to maintain technological superiority, but its expensive high-tech defenses are increasingly countered by the proliferation of relatively cheap but effective weapons like cruise missiles and unmanned aircraft.
Without a more efficient and cost-effective method of knocking enemy munitions from the sky, the United States risks losing future conflicts with peer competitors that wield capable yet inexpensive munitions, experts agreed.
A new set of weapons straight out of Star Wars that cost dollars or pennies to fire could flip the price-per-shot equation in favor of the United States. When facing enemies with ballistic missiles and integrated air defense systems, the most economical way to counter incoming barrages could be blasting them out of the sky with concentrated beams of directed energy, said Mark Gunzinger, senior fellow at the Center for Strategic and Budgetary Assessments.
“As we look to the future toward potentially more contested operational environments where our enemies have precision defenses … that can drive us to need to use more [precision-guided munitions],” Gunzinger, said at a recent forum on directed energy weapons hosted by the George C. Marshall Institute.
“Let’s face it, we’re upside down in this cost-imposition calculus,” he added. Fielding directed energy weapons “would help reverse the trend we see today … where the Navy has to spend more and more and more to defend the fleet at the expense of its offensive punch.”
Despite its promise for cheap, high-rate shipboard missile defense, spending on solid-state laser research-and-development has remained relatively flat since fiscal year 2011 when it was at a high of about $400 million. The overall budget for laser programs has since fallen to $350 million.
Lasers and other directed energy weapons can reverse the trend in favor of the United States because they cost next to nothing to fire and have almost limitless magazines, said Ronald O’Rourke, specialist in naval affairs at the Congressional Research Service.
The Navy fires expensive munitions at targets — be they incoming missiles, small attack craft or shore defenses — that cost the enemy comparatively little if destroyed, O’Rourke said during the Marshall Institute panel.
“That is not an affordable game. If you were to continue it with large numbers of engagements, you would quickly find that you are on the wrong side of that equation economically.”
Another advantage is the deep magazine that electrically powered lasers would allow aboard ships.
“Even if you are shooting at small boats and UAVs, [lasers] can help you reserve your higher cost weapons that you have aboard in fixed or finite numbers for the kinds of targets that really need those weapons,” O’Rourke said.
Unlike a missile that simply explodes on impact, lasers offer effects other than blowing threats out of the sky. The systems allow commanders to choose from a menu of graduated lethality that gives them tactical flexibility, O’Rourke said.
All the services have their own directed energy roadmaps outlining development and operational plans. The Air Force in 2007 tested a chemical oxygen-iodine airborne laser mounted on a Boeing 747-400F intended for use against tactical ballistic missiles. Funding was cut in 2010, followed by cancelation the next year at the behest of then-Defense Secretary Robert Gates.
The Navy is interested in electrically powered lasers that can draw power from existing shipboard power grids. Though generally more potent, service officials have turned away from chemically generated lasers that would require ships to stock a new, potentially caustic, fuel source.
The free-electron laser, for example, offers potential for scaling up to megawatt-class power levels, O’Rourke said. But the technology to achieve that capability is less developed than solid-state lasers. It would also require a lot of shielded space — a room between 60 and 100 feet long, several feet wide and several feet tall — aboard a ship because the laser produces X-ray radiation, he said.
Because of those shortcomings, the Navy’s emphasis has shifted to the solid-state laser, which takes up far less room and is nearly operational.
In the short term, the service wants to fire lasers at small boats and UAVs that can be disabled or destroyed with lower-power systems. Once the weapons can be safely amped up with more power, plans are to use them for defense against anti-ship missiles.
“The Navy is taking lasers to sea with short-range, self-defense engagements in mind,” O’Rourke said. Having relied on advancements in laser technology achieved through other Defense Department divisions and industry, the Navy was able to develop operationally viable weapons at relatively low cost. It also will likely be the first service to deploy such a laser in an operational environment.
The laser weapon system, or LAWS, developed in part by the Office of Naval Research, will be installed aboard the USS Ponce afloat forward staging base this summer.
“The leaps and bounds in solid-state laser technology over the last 10 or 15 years have been quite considerable and essentially what is making it possible to talk about using solid-state lasers for military purposes,” O’Rourke said.
LAWS is essentially six lasers strapped together whose beams converge on the target, creating more powerful effects. The system last year was installed on a destroyer and successfully caused a small drone to burst into flames mid-air.
“One of the real advantages of this experiment will be to put this laser in the hands of sailors at sea so that they can discover how to use it … and to help socialize the concept of lasers within the Navy and among Navy personnel,” O’Rourke said.
The Navy has also developed a slab laser that has a coherently combined beam of 105 kilowatts, the strongest to date. That laser has been tested at sea against small boats. Work is ongoing to scale the system to higher powers of 300 kilowatts or more, he said.
Lasers and the electromagnetic rail gun currently under development are often mentioned in the same breath during discussions of “next-generation game-changers” for the Navy, O’Rourke said.
“These weapons solve an economic problem for the Navy in terms of cost-exchange ratio and the other problem in terms and depth of magazine. These weapons, if they can be successfully developed and engineered, can solve the problem the Navy now faces … going up against large-scale opponents with capable [anti-access, area-denial] forces,” O’Rourke said.
Smaller versions of the solid-state laser could soon find a home on the roofs of Army and Marine Corps vehicles for use against enemy missiles and drones, which like cruise missiles are becoming more affordable and widespread.
The Army has developed the high-energy laser mobile demonstrator to counter rockets, artillery, mortars, drones and missiles. Gunzinger said it would be possible to outfit a Stryker wheeled combat vehicle with a laser of up to 50 kilowatts that could fire 60 shots without recharging and 2,000 shots before refueling. The service is also considering a 100-kilowatt laser that can be hauled by heavy expanded mobility tactical trucks.
ONR recently awarded contracts worth $22.6 million for development of the ground-based air defense system, or GBAD, designed to blast inexpensive unmanned aircraft from the sky.
The largest of those awards — $10.7 million — went to Raytheon Co., which will design and build a high-energy laser “suitable for integration into a light tactical vehicle.” The technology will be derived from previous efforts funded by the Defense Department’s high-energy laser joint technology office’s robust electric laser initiative.
Another $6 million contract was netted by L-3 Communications Corp. for the beam director assembly that will aim the laser and follow a designated target.
“The traditional method of using missiles and guns against a very low-cost UAV is pretty much a failed strategy in the sense that we get priced out of the market real quickly,” Lee Mastroianni, program manager for force protection in ONR’s expeditionary maneuver warfare and combating terrorism department, told National Defense.
Using lasers for protection against drones is “pennies per shot, reusable, as long as you can feed it power and cool it, you can keep firing it,” he said.
The core of the program is in creating a system that is capable of accompanying Marines during expeditionary maneuver operations. That will require ruggedization of the laser and its components, including electronics and power supply.
Development of the GBAD system is under the umbrella of the future naval capabilities program, a science and technology effort to mature systems to a readiness level appropriate for a military utility assessment, he said.
ONR is funding two laser systems. The first is a 10-kilowatt demonstrator that will come online in late winter or early spring. Plans are to then build a 30-kilowatt laser packaged to fit on a Humvee or joint light tactical vehicle by early fiscal year 2016, he said.
“In terms of power, the Marines want flaming balls of wreckage falling from the sky,” he said. “That is our program goal.”
As promising as directed energy weapons are in bending the cost equation of air defense in favor of the United States, they have some glaring limitations. Mastroianni said the Marines do not expect such systems to work in all weather conditions.
“I don’t think anyone is under those illusions. You will always have missiles and guns, but missiles and guns alone are inadequate. What we are trying to figure out is how much of the problem a laser can bite off.”
In their current iterations, lasers also are limited to line-of-sight engagements because they must be continuously pointed at a target to deliver energy.
“Level of operational utility versus size, weight and power are the key issues to be solved,” Howard Meyer, science adviser for the assistant secretary of defense for research and engineering, said at the Marshall Institute. “There are commercially available lasers, but they are designed to fire a beam less than a foot [long] while the military needs to shoot through the atmosphere.”
Research is ongoing into beam direction, control, pointing and tracking and power sources for the primary purposes of decreasing system size while boosting laser power, Meyer said.
There are limitations associated with atmospheric absorption, scattering and turbulence that the Navy in particular must understand. Because maritime lasers would fire from close to the ocean surface, moisture and other particulates can disrupt a laser beam, O’Rourke said.
“Lasers on ships should probably not be considered an all-weather weapon, and for that reason alone you would want to look at lasers as a complement to existing self-defense weapons, not as a substitute,” he said.