In April this year, the US Navy announced plans to deploy a solid state laser on a warship for the first time. The object is to carry out at-sea demonstration trials on-board USS Ponce – an Afloat Forward Staging Base (Interim) (AFSB [I]) vessel – during the fiscal year 2014, as part of a wider programme of directed energy research. This work has also included the temporary installation of a Laser Weapon System (LaWS), built by the Naval Systems Command aboard the guided-missile destroyer USS Dewey in San Diego in July 2012. The laser in question is a combination system of commercial fibresolid state lasers developed by the Naval Research Laboratory.
In an interview with ScienceOmega.com, Dr David C Stoudt, Senior Director for the Naval Capabilities and Readiness Office of the Deputy Under Secretary of the Navy for Plans, Policy, Oversight and Integration, outlines the work being conducted in a concerted effort to put directed-energy weapons (DEWs) into the front line.
"A DEW requires no projectile," Dr Stoudt begins. "Instead, it uses energy to affect its target in a desired manner. Directed energy can be deployed in various ways to achieve a range of outcomes – both lethal and non-lethal. Whilst DEWs have been designed to supplement rather than replace the warfighter’s existing arsenal, they do possess certain advantages over their traditional kinetic counterparts
"The term ‘directed energy’ actually covers a number of different technologies. High Energy Lasers (HELs), High-Power Radio Frequencies (HPRFs) (sometimes referred to as High-Power Microwave (HPM) weapons), millimetre-wave weapons, charged particle beams etc. – all of these devices engage their targets in a non-kinetic way."
Directed energy weapons only require a source of energy. This can be generated in a number of ways: chemically, electrically or explosively. DEWs lend themselves to the arena of weaponry because of the ways in which they interact with their targets.
"For example, a HEL is akin to a blowtorch at range," Stoudt continues. "HPRF weapons, on the other hand, couple into wiring and circuitry in order to disrupt their targets. Essentially, the trick is to devise a system that can interact with a target at a tactically significant range that is of interest to the warfighter. If you succeed in doing this, you might have something that can be turned into a weapon."
Whilst Stoudt is unable to go into detail about the exact ranges of DEWs, he stresses that these weapons have been designed with the needs of the warfighter in mind.
"The range very much depends on the type of weapon that you are talking about," he explains. "Generally speaking, the higher the power, the longer the range. I can’t really talk about the specifics of the weapons’ ranges. Suffice it to say, when you deal with warfighters, you understand what their mission sets are and the ranges that they require. You have to determine whether or not you can marry these requirements with the technologies that you are developing."
Directed-energy weaponry offers several advantages over conventional weapon sets. Because lasers travel at the speed of light, there is no need for warfighters to compensate for target movement. The effects are – to all intents and purposes – instantaneous. Neither is there any need to account for factors such as gravity or wind speed. Whilst Stoudt is keen to highlight the continuing importance of traditional weaponry, he also acknowledges that DEWs offer potential benefits in terms of cost effectiveness – a point also made by the Chief of Naval Research, Rear Admiral Matthew Klunder, in a statement on the deployment of a solid state laser on the USS Ponce in April. "Our conservative data tells us a shot of directed energy costs US$1," said Klunder. "Compare that to the hundreds of thousands of dollars it costs to fire a missile, and you can begin to see the merits of this capability."
DEWs should be viewed as being synergistic with other types of weapon, Stoudt contends. "It isn’t necessarily the case that DEWs are going to replace kinetic-energy weapons, but they may represent a better choice for warfighters in certain scenarios. These scenarios might involve asymmetric threats. Unmanned Arial Vehicles (UAVs), for example, are fairly inexpensive. We have plenty of kinetic-kill capabilities that can engage their systems. However, it isn’t always cost effective to deal with these threats in this way. Since DEWs have a much lower cost-per-shot number than a lot of kinetic-kill capabilities, they offer a more attractive option for certain target sets."
One of the main benefits associated with the kinetic weapon is its portability. How do directed-energy devices compare in this regard? Are they accessible in the field, for example, or are DEWs typically larger affairs?
"Some of these weapons can be deployed in the field," Stoudt clarifies. "This all depends on their size, weight and power (SWaP). These are vital considerations when assessing military capabilities. Some directed-energy devices use average power to engage their targets whereas others use peak power. Typically speaking, if a weapon requires average power to operate, it tends to be associated with a larger energy source."
As with any defence related technology, specific details concerning directed-energy devices are restricted. Stoudt is, however, able to divulge that DEWs are already being used in the field. As he reveals, this is an integral stage in the development process.
"In some cases, warfighters already have access to DEWs in the form of ‘combat prototypes", he says. "Some of these systems are at a stage in development whereby they are ready to be put into operational environments. This means that we can begin to develop tactics, training and procedures (TTPs) and Concept of Operations (CONOPs). The operational feedback from warfighters to technology developers provides insight into how the systems can be improved."
"The US Navy recently announced that it is ready to follow a similar route with the LaWS," he continues. "This too could be referred to as a combat prototype. The system is out there in the hands of the warfighter and this means that we are able to collect operational feedback. This process is critical, especially when you consider the fact that we are dealing with a new type of war-fighting capability."
Once operational feedback has been gathered and used to refine the designs of combat prototypes, researchers can begin to consider the next stage: rolling out the technology to larger numbers of service personnel. But what challenges are DEWs likely to face in terms of larger-scale manufacturing?
"I guess that this is always a matter of degrees," replies Stoudt. "However, in the sizes and numbers that we typically discuss for these kinds of capability, I haven’t seen anything to suggest that the market will be unable to supply the necessary materials."
"The US Navy is taking this technology very seriously, both in terms of HPRF and HEL capabilities. We are taking steps to figure out how to get these tools into the fight as soon as possible, and in the most cost-effective way possible. Keep in mind that unless the requirement of cost effectiveness is met, these systems are unlikely to see the battlefield."