MISSILE DEFENSE

Navy’s Laser Gun Nears Critical Test

1/29/2014
By Sandra I. Erwin

Over a 12-month trial deployment in potentially hostile waters, sailors will attempt to prove whether laser beams can serve as legitimate weapons against approaching small aircraft or high-speed boats.

For Navy officials and military contractors, much is at stake in the success of the demonstration. The performance of the fiber solid-state laser — to be installed aboard the USNS Ponce amphibious transport ship — will be seen as a litmus test for the wider use of energy-based weapons.

The Navy has spent about $40 million over the past six years on research, development and testing of laser weapons, although it has been pursuing the technology in various forms for much longer, with modest results.After decades of experimentation, so-called directed-energy weapons have yet to graduate from science projects to big-ticket procurements.

Officials and outside experts believe the Navy now has a real motivation to adopt speed-of-light weapons even though it has an ample arsenal of proven kinetic missiles and warheads. The reason is simple economics. A high-power solid-state laser, if installed on a ship that can generate hundreds of kilowatts of electricity, can provide firepower for as little as a dollar per shot, according to some estimates. By comparison, conventional naval gun rounds and missiles cost tens or hundreds of thousands of dollars a piece.

The installation of the laser on the Ponce will begin this summer, said Chris Johnson, spokesman for the Naval Sea Systems Command. No firm dates have yet been set. “We are using this deployment as an opportunity to test a weaponized laser in an operationally relevant environment, similar to where future systems would likely be used,” he said. If the Navy decides to move forward with the project, the first operational weapons could enter the fleet sometime between 2017 and 2021.

Since being designated as the test bed for a laser weapon, the USNS Ponce has moved into the spotlight. The ship was taken off commission in 2011 but was resurrected in 2012 as an “afloat forward staging base” and transferred to the Military Sealift Command. Navy officials saw it as a fitting platform to experiment with lasers at sea.

The exact power level of the laser gun that will go on the Ponce is classified. Outside experts speculate that it is probably somewhere between 15 and 50 kilowatts.

Although laser weapons have been derided for years as technological pipe dreams, analysts are now optimistic that the military, and particularly the Navy, intends to deploy these systems and use them in defensive and offensive roles.

“The Navy has a rich history in this area,” said Nevin Carr, retired Navy rear admiral and former director of naval research. “The current momentum is in the direction of fielding a solid state laser system in an operational context,” he told National Defense.

Ronald O’Rourke, naval analyst at the Congressional Research Service, said high-energy military lasers have reached the point where they are capable of countering some surface and air targets at ranges of about a mile, and could be ready for installation on Navy surface ships over the next few years.

The Navy started shooting down hard targets with megawatt chemical lasers in the 1980s, but these turned out to be impractical for shipboard use. Chemicals are undesirable on ships because of safety hazards and logistics requirements.

Solid-state lasers are easier to engineer into weapons but do not achieve the high power levels that chemical lasers do. Besides fiber solid-state lasers, the Navy has researched other variants, including slab solid state and free electron lasers. Fiber solid-state lasers are widely used in the manufacturing sector for cutting and welding metal.

A slab solid-state laser was tested successfully in April 2011 in the Pacific Ocean. A 20-kilowatt “maritime laser demonstrator” built by Northrop Grumman Corp. was fired from a moving decommissioned Navy warship and managed to destroy unmanned boat targets by burning their engines.

The Army and the Air Force also have developed slab solid-state laser prototypes and continue to test them.

Only the Navy has invested in free electron lasers, a technology that is commonly used in Department of Energy particle colliders for basic subatomic research. The Office of Naval Research built a prototype that is about the size of a football field and is located in Newport News, Va. O’Rourke noted in a CRS report published in August that the project has been put on the back burner as the Navy focuses on solid- state lasers as the quickest way to get a directed-energy weapon to the fleet. Like chemical variants, free-electron lasers are said to be scalable to megawatt-power levels, but their size makes them inoperable for use on ships or aircraft.

A key challenge for solid-state lasers at sea are their ability to propagate light through the atmosphere in a wet, maritime environment, or through smoke and fog. Lasers tend to perform better in a vacuum.

Industry engineers who have worked on the Navy’s laser weapon that will go on the Ponce believe those performance hurdles have been thoroughly studied and can be overcome.

“There are techniques to cope with salt and sea spray,” said Don Linnell, of L-3 Integrated Optical Systems. The company supplies the “beam director,” a subassembly that includes a gimbal and optics to track objects and direct the laser beam. “We are going to learn quite a bit with this first deployment aboard the Ponce,” Linnell said in an interview.

“We've been working that system for a couple of years,” he said. The Navy launched the program about four years ago. The laser first was restricted to a laboratory, then was moved to a destroyer, the USS Dewey, and now will be headed to the USS Ponce for deployment. The weapon, which uses an existing telescope, can be guided to targets by radar tracks provided by the Phalanx close-in weapon system or other targeting sources.

“We certainly think the Ponce deployment is going to be a big deal for the future of directed energy,” said Linnell. The financial benefits of laser weapons, once in the fleet, could be huge, he said. A laser ought to be viewed as a bottomless magazine that can be kept loaded as long as there is power on the ship, he said.

If the Navy chooses to equip more vessels with laser weapons, it will need to expand electricity storage capacity on ships. Greater use of laser weapons could be a boon for companies that supply shipboard energy management technologies. Depending on the size of future lasers, Navy ships will need massive batteries to store electricity, said Eric Lindenbaum, vice president of Navy and maritime programs at DRS Technologies. The company makes energy storage modules that are used in Aegis destroyers as part of a Navy effort to cut down on fuel use. Lindenbaum, like others in the industry, sees “critical mass starting to form” in the Navy’s directed-energy weapons program.

Whether there is big money to be made in this market is still to be determined. Major defense contractors had hoped that, by now, directed-energy weapons would have transitioned to big-ticket procurements. Some firms left the market when they realized the return on investment would be years, or even decades, away.

Textron Defense Systems in 2009 formed a directed-energy weapons business line with a staff of 100 employees. Company executives at the time estimated the market would reach about $1 billion.

But after three years of disappointing sales, Textron shut down the division. The former head of Textron’s directed-energy business, John Boness, said the company was disappointed by the Defense Department’s slow progress in this area. “Textron, like others, were in the game for a long time, making substantial investments, thinking the payoff was around the corner.”

The Defense Department is “very conservative” in adopting new technology, Boness said in an interview. “It takes a while to absorb.”

Contractors that are still in the game are betting that solid-state lasers are ready for use in weapon systems, although the devices have achieved limited power levels so far. Most of the military’s solid-state laser weapons have reached 10 to 20 kilowatts.

Lockheed Martin, which acquired laser manufacturer Aculight in 2008, announced Jan. 28 that it has built a 30-kilowatt electric fiber laser. It combines multiple fiber lasers into a single beam of light. The company, which financed the project with corporate R&D funds, plans to market it for use on military platforms such as aircraft, helicopters, ships and trucks."

Most laser weapons that are now available, Lockheed noted in a news release, are inefficient as their demand for power and cooling result in bulky systems that are difficult for the military to integrate into vehicles and maintain. Lockheed’s laser is said to consume 50 percent less electricity than comparable systems.

The gold standard for weapon-grade lasers is 100 kilowatts, or enough power to destroy soft targets like small boats and drones. Carr said the Navy has demonstrated destructive effects at lower power levels. One of the hardest technical issues in scaling up power is efficient thermal management for the lasing medium, said Carr, as it gets too hot and breaks down. Beam quality and control are also challenging but researchers are making progress, he said.

To shoot down a hard target like a cruise or ballistic missile, megawatts of power would be needed. “I don't think solid state lasers are going to do that for a long time, if ever,” said Carr.

O’Rourke said technological, engineering and manufacturing challenges should not be underestimated. “In spite of decades of development work … the Defense Department has not deployed an operational high-energy laser weapon system.”

The Navy’s Ponce deployment is a remarkable feat, considering the spotty track record of directed-energy systems, Boness said. “It used to be the Air Force and Army would lead the way in directed energy. Now the Navy is moving up.” One of the military’s highest profile failures was the Air Force’s airborne laser, which sought to equip a Boeing 747 airliner with a missile-zapping chemical laser.

After billions of dollars were poured into the program and its utility and cost came into question, former Defense Secretary Robert Gates terminated it in 2010.

Boness said the high-profile termination has fueled the skepticism. “There has never been a ‘program of record’ for directed energy in the Defense Department,” said Boness. It has only been funded by research and development budgets.

Experts insist that lasers, even at higher power levels, will not displace kinetic weapons. “It comes down to the economic argument, as well as the tactical,” Carr said. “Directed energy will not replace traditional weapons any time soon, but they can complement them and help you get more out of the kinetic weapons that are increasingly expensive,” he said. “We have crossed a line to the point where the challenges are no longer strictly technical. Some of the most daunting challenges are financial and operational.” With the military in a budget crunch, he said, “we can't just keep building more expensive missiles and fewer of them. Threats are becoming faster, smarter and more maneuverable.”

Directed energy is “cool science but really is much more than that,” said Carr. “Lasers can be used for multiple missions, including defense, direct attack, tracking, and communications. Under the right conditions, they can provide accurate tracking at long ranges.”

The ability to scale output power gives commanders less-lethal options when they need to warn approaching small boats and determine potential hostile intent, said Carr. That is one of the hardest scenarios for commanders, and a laser gives them an option that can be less escalatory than warning shots.

The Navy eventually has to decide if and how it will use lasers, under what conditions and tactics and legal restrictions. The United States signed a treaty that prohibits the use of lasers to blind people. But there are still concerns about accidental blinding. The United States in 1995, and later in 2008, ratified a 1980 international treaty that bans blinding laser weapons.

Loren Thompson, a defense analyst who runs an industry-funded think tank, said the military’s pivot to Asia and concerns about the Navy’s vulnerability to Chinese cruise missiles should serve as motivators. Conventional missile interceptors cost millions of dollars each, with the newest models now carrying price tags of $9 million to $15 million, Thompson wrote in a Forbes.com article. “A single shoot-look-shoot engagement against a maneuvering anti-ship ballistic warhead might cost over $20 million, and the Navy will have to plan for hundreds of such engagements in a major conflict.”

The Office of Naval Research, meanwhile, is pursuing a ship-mounted laser that would go aboard Aegis destroyers and the Littoral Combat Ship.

Raytheon, BAE Systems and Northrop Grumman are designing concepts for a high-energy laser weapon under a project called solid-state laser technical maturation.
The Navy plans to tap existing technologies from other military laser programs.

Peter Vietti, spokesperson for the Office of Naval Research, said the potential of laser weapons is significant. They could be used not only as defensive weapons in the traditional sense but also in “electromagnetic maneuver warfare,” he said. ‘In the future, and at higher power levels, lasers may have a capability to defeat air threats including cruise missiles, providing a robust ship area defense capability with nearly endless magazines.”

Topics: Armaments, Gun and Missile, Missile Defense, Strategic Weapons, Shipbuilding, Surface Ships, Air Power