Navy dew drops

As the Navy looks at what directed energy weapons it needs for shipboard self-defense, two DEW experts are saying it is unlikely that any one weapon system will be robust enough to satisfy this mission anytime soon. While the Navy's laser experts may show doubt, they call high energy lasers "attractive."

According to Joung R. Cook, the director of the Navy's High Energy Office, and John R. Albertine, the service's former director of DEW programs, a high energy laser weapon system (HELWS) that uses a free electron laser (FEL) offers a new weapon for ships facing new threats.

The fundamental shift in war-fighting "profoundly affects the basic performance requirements placed on potential shipboard HELWS," Albertine and Cook said in a recent paper. HELWSs operating in the littoral environment encounter thermal blooming, a phenomenon that limits the atmospheric propagation of a high energy laser beam. This in turn hampers the weapon's effectiveness. Albertine and Cook described today's threats as no longer clearly identifiable, thanks to small scale conflicts and new defense philosophies. Therefore they advocate FEL, because existing weapon systems were not designed with the new threats in mind. In order to meet these threats, the service must develop the new generation of weapons to support the deployment schedule of future ships, according to Albertine and Cook.

But one defense analyst said this is nothing new. "The Navy is constantly, with a giant C, looking at using a laser as a ship-defense weapon." He called it "pre-Star Wars." With the killing of the arsenal ship and other shipbuilding problems, the Navy won't spend the money to defend ships unless a new surface vessel emerges, the analyst said.

Work being done at the Thomas Jefferson National Accelerator Facility in Newport News, VA, appears to offer a solution. A multi-Watt class FEL that is suitable for shipboard HEL was developed in 1996. The Navy launched the FEL in conjunction with the Department of Energy and several industries (TRW, Hughes Aircraft, Loral and Aerotherm) and laboratories, including the Naval Research Lab. Cook and Albertine said a full-power operation should take place next year.

The Navy is also looking at other parts of the shipboard HEL equation and has been conducting experiments with the Sea Lite Beam Director for several years. Built by Hughes, the Sea Lite uses a system of mirrors and sensors to align and stabilize a laser for target tracking and aiming. It is specifically designed to accept a high-energy laser beam which it focuses and directs at a moving target.

A separate Northrop Grumman paper calls FEL the answer to the Navy's ship self defense question for several reasons, including power efficiency, wavelength selectivity and a superconducting RF accelerator. The new Navy capability may also fulfill secondary missions such as anti-satellite, theater missile defense and low-power deterrence illumination, according to the paper written by Alan Todd and Michael Reush from Northrop Grumman, William Colson from the Naval Postgraduate School in Monterey, CA, and George Neil from the Thomas Jefferson Facility.

Source Citation:Jannery, B. "Navy dew drops." Journal of Electronic Defense 20.n12 (Dec 1997): 39(1). Academic OneFile. Gale. BROWARD COUNTY LIBRARY. 13 Sept. 2009
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