High Energy Liquid Laser Area Defense System

The High Energy Liquid Laser Area Defense System (HELLADS), is a Counter-RAM system under development that will use a powerful (150 kW) laser to shoot down missiles, rockets, and artillery shells. The initial system will be demonstrated from a static ground based installation, but in order to eventually be integrated on an aircraft, design requirements are maximum weight of 750 kg (1,650 lb) and maximum envelope of 2 cubic meters (70.6 feet3).

Development is being funded by The Pentagon's Defense Advanced Research Projects Agency (DARPA).

History
Liquid lasers that have large cooling systems can fire continuous beams, while solid state laser beams are more intense but must be fired in pulses to stop them from overheating. (However, as long as the heat transfer requirements are met, Solid State lasers may run continuously.) In the past, both types of lasers were very bulky because of their need for these huge cooling systems. The only aircraft in which they could fit were the size of jumbo jets.

Need for such a system was reinforced during the 2006 Israel-Lebanon conflict. Israel had participated in similar work in the past by funding the Mobile Tactical High Energy Laser (MTHEL). This system was tested on August 24, 2004, and was found to be effective at neutralizing mortar threats under an actual scenario. However, this test was administered with short, 20 km range missiles.

Development
For the first few years of the program General Atomics Photonics division was the prime contractor. The design combined the high energy density of a solid-state laser with the thermal management of a liquid laser. Dubbed the "HEL weapon", the initial prototype demonstrated firing a mild one kilowatt (kW) beam. Phase 3 of the program in 2007 demonstrated 15 kW power in a laboratory setting, and at the end of 2008 under the General Atomics bid, Lockheed Martin was selected as the weapon system integrator.

In September 2007, DARPA contracted Textron Systems to supply an alternate laser module using its proprietary “ThinZag” ceramic solid-state technology. Unlike the GA/Lockheed partnership, Textron will also perform the system integration function for their device. DARPA planned a “shoot-off" between the two contenders in 2009 to determine which would be funded to continue the program to further phases.

The more powerful version will produce a 150-kW beam capable of knocking down missiles with the weight and size requirements for fitting onto fighter aircraft or a Humvee. In mid 2008, Jane's Defence Review quoted the US military that the program is on schedule to meet this ground test. Phase 4 of the program, involving outdoor testing of a weapon-power laser against tactical targets, was planned for 2010.

A prototype is expected to be available by the end of 2012. DARPA plans to use the completed prototypes against targets at White Sands Missile Range in early 2013. This will include ground testing against rockets, mortars, and surface-to-air missiles.