For nearly two decades, precision guided munitions have become an increasingly important staple in the U.S. military inventory. First demonstrated in combat during the first Gulf war, the increased numbers and capabilities demonstrated a decade later in Iraq and Afghanistan became so accepted that any collateral damage – especially civilian casualties – has now become unacceptable to the public.

As the second decade of the 21^st century dawns, however, the nature of PGMs is about to change. While missiles, bombs, mortar shells and even guided bullets will remain the heart of the arsenal, a new technology is emerging with the potential to dramatically change the face of combat.

Directed energy weapons are perhaps the ultimate in precision strike. While experiments to date have involved the use of chemical lasers – which tend to be large, expensive and dependent on dangerous chemicals that need periodic replenishment – the future is likely to rest with solid state lasers and significantly advanced liquid lasers.

Two major directed energy weapons programs currently underway are the Joint High Power Solid State Laser (JHPSSL), funded by the Joint Technology Office and the Army to produce a lab-based 100KW technology demonstrator; and the High Energy Liquid Laser Area Defense System (HELLADS), a DARPA-funded program to demonstrate an actual 150KW laser weapons system. JHPSSL is about midway through a three-year program, while HELLADS is approaching demonstration of a 50KW unit cell demonstration. That is expected to be followed by a two-year phase to build and demonstrate a full 150KW capability, then transitioning the technology to the Air Force to test on an airborne platform.

“DARPA’s goal [with HELLADS] was to take the present state-of-the-art and try to make an order of magnitude leap in terms of weight and volume. If you can build and demonstrate a laser of this power to those specifications, it then would be compatible with the kinds of platforms on which you would want to deploy the laser, such as an F-35. That has really been one of the main obstacles previously – they were simply too large and too heavy,” Dr. John Boness, vice president-Directed Energy Weapons at Textron Defense Systems (Wilmington, MA), tells The Year in Defense.

“The publicly released numbers call for building a system at 5kg per kilowatt – or 750kg – and you’re pushing the limits of technology in almost every area to meet those requirements. You have to miniaturize systems by an order of magnitude, the supports and optical systems require lightweight materials, there are considerations involving pulse power and thermal management. It was viewed as a DARPA-hard engineering challenge when we began, but I think we’re doing very well.”

As happened with UAVs, which rose and fell in miliary interest for decades before coming into their own thanks to technological advances in the 1990s, lasers have been studied for at least three decades. Until now, however, they were not powerful enough at a size, weight and logistics requirement to be practical. HELLADS and JHPSSL are strong indicators that this is about to change.

“We would certainly like to see 100KW prototypes in the field within five years – and I think we are on a development pathway now to put demonstrator/prototype systems, especially for the Army and Air Force, into that timeframe. To really put them into the field, in combat, would be the next step, perhaps out in the 7 to 10 year range,” Boness says. “In smaller power ranges, if you can convince the military they have a battlefield utility, they could be available more quickly.”

While all the services are pursuing directed energy, it is not seen as a replacement for the next generations of PGMs, he adds, but as a complementary capability, providing combatant commanders with greater flexibility to address whatever circumstance they may encounter. And to achieve true precision, even directed energy weapons will rely on many of the guidance and targeting technologies being developed for current and future PGMs.