The U.S. Department of Defense is exploring a range of novel concepts and weapons systems as it attempts to re-equip and retrain the armed forces for future conflicts, while also reinvigorating conventional deterrence capabilities alongside NATO and other allies. One particularly ubiquitous threat is that posed by the widespread use of small class one and two unmanned aerial systems (sUAS)—otherwise known as drones—by both non-state groups like Daesh, as well as state adversaries.

In Nagorno-Karabakh, internationally recognized as part of Azerbaijan, and during the ongoing conflict in Ukraine, these sUAS have been used to spot and correct for indirect artillery and mortar fire for devastating effect, as well as to directly drop small munitions or crash into targets with a small warhead attached as cheap loitering munitions. This is hardly a new threat for the U.S. military and its allies, but it is one for which an affordable and effective solution which can be employed at scale has yet to be procured in the West.

Directed energy weapons, and in particular high-energy lasers (HELs) and high-powered microwave (HPM) weapons, have long been viewed as a potential answer to providing cheap and effective short range air defense (SHORAD) against these asymmetric threats, as well as potentially against larger UAVs and even rocket-artillery and mortar rounds. However, traditionally, the technology has remained a few years from being ready for regular use in the field, with difficult challenges still to solve around battery storage capacity, cooling capacity and beam control.

However, thanks to a series of trials with the U.S. Army and significant investment in technology maturation, systems integration, and production facilities, one of the leading manufacturers of HELs believes that their technology is mature enough to cross the threshold into regular use as part of the U.S. and allied military arsenals. 

Raytheon Intelligence & Space (RI&S) has several relatively mature HEL programs, including the High Energy Laser Weapon System (HELWS), and a more powerful system mounted on the US Army’s Stryker vehicle as part of its Directed-Energy Mobile Short-Range Air Defense (DE M-SHORAD) program. To find out more about how these systems work and why they believe a tipping point has been reached in terms of maturity, we sat down with Michael Hofle, Senior Director for RI&S' High-Energy Laser product line, and Evan Hunt, Director of Requirements & Capabilities for High Energy Lasers and Counter-UAS. 

Given that Raytheon Technologies makes a tiered range of quite a few different directed energy weapon systems, could you start by explaining the various energy, mission set or weight categories which you use for them? 

Sure. So, it's oversimplifying a little bit to just talk about power when it comes to laser weapon systems. To get effective laser energy on a target, you need power, but you also need good beam quality, and you need a very advanced tracking sensor and algorithms associated to maintain that beam on a target as you engage. So, I should caveat the following power classes with that.

But, in general, we look at the market in three different areas. There's a 15-kilowatt power class, which is the smaller systems you see, such as the HELWS (High Energy Laser Weapon System) on a light tactical vehicle or in the back of a commercially-available pick-up truck. This category of systems is really good at dealing with group one and two drones, and we’ve even proven that we can reliably take down group three drones.

Then we move into a different power category, which is larger. You need a larger vehicle, and it has some longer lead times. That is roughly 50-kilowatt and that gets you into what we call short range air defense (SHORAD). It's no longer just a counter drone, it's now short-range air defense. You can do group one, two and three drones, the larger drones that are longer range. We've also proven that we can do some counter rocket artillery and mortar work. 

We’re excited to show the world that our high-energy laser weapons are real and ready to defend against more than drones—we proved it’s possible to stop rockets, artillery and mortars in combat with a fully-integrated HEL system on a Stryker. In combat-realistic testing we proved that HEL is ready to take on the challenge and be put in the hands of commanders and soldiers.

Then, beyond that, there's everything above that, which is 100-plus-kilowatts. That is still firmly, I’d say, in the science and technology space. Theoretically, there are a lot of advantages to using lasers to counter ballistic missiles and hypersonics. You've got very fast threats, and lasers are a speed-of-light weapon. But you need very large platforms to accommodate the appropriate laser power. There are also a lot of heat issues that we're still working through at all levels of the system to make this category of weapons more practical. My main point is that you'll hear a lot about higher power classes, but they are not nearly as ready as these 15-kilowatt and 50-kilowatt systems that you see Raytheon Intelligence & Space fielding today.

Presumably there's also a caveat to add about the engagement window that you're typically working within for each target class. So, for something that flies relatively slowly in a non-cluttered environment, you presumably have a longer acceptable target dwell time than for a hypersonic weapon system, where clearly if you're trying to intercept it, you are dealing with seconds within field of view.

Air defense is one of our specialties, so we look at the threat first, always. Lasers are very well matched, very well matched, indeed, probably the best effector for the small drone threat and the rocket artillery and mortar threat. 

These are current asymmetric threats. You can look across the world. You can see it advancing at an incredibly rapid rate. It's changing the nature of warfare, and so lasers are great for those small, swarming asymmetric threats—rockets, artillery and mortars included—which are shorter range, as opposed to solutions for hypersonics, one day in the future.

One of the things that makes our system so successful in difficult, cluttered environments is our laser beam director. It’s based on our best-in-class electro-optical/infrared sensor—called the Multispectral Targeting System. MTS has more than three million operational hours and it can not only identify and track highly maneuverable threats in clutter, it can also track and target on the move, fire the laser at the exact spot on the drone or shell that you want to target, and survive the toughest combat conditions.

Given that there's this ubiquitous presence in a number of recent and ongoing conflicts, presumably you've seen quite a lot of demand from DOD customers and other potential users around the world for laser systems specifically capable of engaging small UAVs, group one, group two and potentially up to group three, as well as the counter rocket artillery and mortar mission? Has that been an increasing demand set in the last year or two?

Yeah, we have an overwhelming amount of international demand for counters to those threat sets. We have our first export with the laser weapon system. We are working with our UK subsidiary, Raytheon UK, and the UK MOD on a program called Project Swinton to prove that the technology is ready for the UK warfighter.

I think right now, a lot of our international customers are still trying to get their arms around which weapon systems are right for those threats. We're talking about a new threat—the swarming drone threat. And even for more traditional rocket artillery and mortar threats, it’s a new mission because there haven't been many great defensive options before. So, we are currently licensed to export the technology to more than 40 countries and we are having a lot of conversations with a lot of partner nations.

In terms of the systems that you are working on and talking to customers about it at the moment, what are the main high energy laser weapon systems that are currently being produced by Raytheon Intelligence & Space?

Sure. Clearly, our customers see lasers as a needed layer of defense, and our HEL weapons are proven to plug right into existing air defenses to stop threats at distance. They can also operate as fully-integrated, standalone systems, depending on the need.

Countering different kinds of threats requires a customized approach, and our HEL systems work with a long list of sensors, effectors and command and control systems for maximum flexibility.

So, we've sold four different 15-kilowatt systems to the U.S. Air Force. Over time, we've been making incremental improvements to those systems. Several of the systems are integrated into a Polaris light tactical vehicle—a dune buggy-looking vehicle—and the most recent one we sold to the U.S. Air Force is a palletized configuration that can be moved and mounted anywhere it’s needed. Then, of course, Evan mentioned the 15-kilowatt system that we are exporting to the UK. 

Then our flagship program is the 50kW DE M-SHORAD, which is highly capable and proven. Everything you need—power, thermal, sensors, radar—is right there in the vehicle and all you need is diesel to run it. 

We're actually building four of these systems concurrently in Texas, which is a big deal. 

When you talk about weapon systems, tanks being built in a quantity of four is probably not that interesting to a lot of people. But for laser systems, that's pretty much unheard of. So, we've invested a significant amount of money into putting together the capability so that we can produce these systems at quantity.

No one's ever done that before. We're pretty excited about building four of these systems at the same time. Those are all going to get fielded to soldiers at the end of this year. The promise there and the hope is that we're going to be building more and more of these and getting them out to the warfighter. High energy lasers have been stuck in the science and technology world for the past 30 years. The running joke is that every year, lasers are five years away. But we're here now, proving that our HEL is ready. The threat is real, and so is the solution.

In terms of other areas, we've done some work in the past on putting some of these systems into airborne vehicles as well. In fact, we were the first to put a laser on target from an airborne platform. So that's also an area that we continue to explore. We think there could be a pretty sizable market there and a need for countries to have that airborne type of capability.

It’s also worth noting that we have this scalable architecture that's also very modular. It's basically four line-replaceable units; four boxes and one sensor ball that acts as the EO/IR sensor and the beam director for the laser. So, we can scale and repackage those four boxes and a ball into a variety of configurations for a variety of platforms. We can put it in a pallet. We can put it in an airborne pod. We can put it on a light tactical vehicle, a medium tactical vehicle, or other customer vehicles.

So, it's not really about the vehicle at this point. It's about the technology, which is clean and efficient and self-supporting, and so it's very easy to integrate with a variety of vehicles and a variety of command and control networks.

So you mentioned the modular nature of it. How does that interact with the presumably very varied space, weight, power and cost (SWaP-C) constraints that weapon systems have to operate within for the various different domains? Anything from what can be supplied from a Ford Class carrier with however many nuclear reactors and as much space as you want, down to trying to fit something in a pod under a fighter…

Clearly, you're dealing with a huge variety of SWaP-C configurations and target sets there. You mentioned fully scalable, but what do you see as the main opportunities and limitations in terms of diversifying this technology across the various DOD mission sets?

With the U.S. Army program, you're on a Stryker, which is in some respects a big vehicle, but in many respects it's a very small vehicle. One of the most important things in designing a laser system on a Stryker is that you have to maintain the ingress and egress pathways for the soldiers. So, even though externally it looks like quite a big vehicle, you do have some pretty significant SWaP constraints.

With the architecture that we have, the design is flexible in the sense that there are certain areas or subsystems where you can shrink down and perhaps push that SWaP over to other parts of the system. With the HELWS, the first time we put it on the dune buggy was just to prove that it could be done. Here's a very small vehicle, and we can form these different subsystems into a package that you can put on that small vehicle.

But at higher power levels, the SWaP requirements go up. We have done some research and development in how to decrease that, so that you open up the envelope for different platforms. But even on the ships…for most of the ship-based missions, they want hundreds of kilowatts in terms of output class so, even though you've got a big ship, you've also got a big laser at 300-kilowatts. So the SWaP is definitely a challenge even on what you would consider your largest platforms.

To return to the SWaP-C point again though, I think what's interesting is that we're at the stage right now where lasers are finally small enough, efficient enough and repeatably producible enough to be fielded in tactical platforms without obstructing warfighter needs like safety, ingress and egress. We can finally pack everything in and that's because of advancements in fiber lasers, but also in lithium ion batteries and all the different components that go into laser weapon systems—the modern laser weapon systems today that we create.

To that point, Evan, it is worth foot stomping that on the Stryker platform, it's the first time anybody has put a laser of that power class in a vehicle with an onboard radar. The entire system is on one vehicle. There's no support equipment that has to follow it around to provide power or radar queue or anything like that. Also, you don't need to tow extra missiles behind you, all you need is the diesel fuel to power that Stryker, and you've got the whole thing.

How does that affect crewing and support arrangements for field testing and service use? 

That's a good point because when I talked about a 30-year history of lasers and everything being five years away, traditionally these systems have been operated and tested by engineers, scientists with PhDs, or people who can go behind the scenes in the software and change things and then put it back.

One of the big drivers of the DE M-SHORAD program is that we're not doing that. The Army was very specific. We're going to have soldiers at the controls. Soldiers are going to be training, and soldiers are going to be shooting down targets and the Raytheon Intelligence & Space team is going to be off far, far away with no communications to the soldiers. 

We did the same thing with our HELWS deployments overseas with the U.S. Air Force in multiple different combat areas. And you've heard the U.S. Army say it about DE M-SHORAD—that the systems have had thousands of soldier touchpoints. But we've got many thousands of soldier and airman touch points across the architecture. So the evolution of our system has been directly informed by warfighters giving their honest feedback, saying, "Oh, I like this. I don't like that.” 

There's one operator required for the system, and it's very easy to train those operators. It doesn't take weeks or months of schooling. We've trained operators in a couple of hours. They use an Xbox controller and direct the laser onto the target. The engagements are more and more automated than they've ever been in the past. So, you can have three people in the vehicle, but you can also park that vehicle and operate it remotely if you had to.

In terms of technology readiness levels (TRLs) or in normal English, the journey from science fiction to bog-standard kit in the hands of a GI or a Marine, what kind of level would you say your systems are now at? 

I think the one thing that would prevent us from claiming something like a TRL 9 is that we're not in full-rate production. That is certainly the goal, and I think we're on the right track. We're in low-rate production today, which is significant. We’re building four now, as I mentioned, and when you talk to someone who's been working on lasers for 30 years, if you tell them "Hey, we're going to build four of the exact same laser system at the same time," their eyes will pop up.

That's a big deal. We are working with the Army on the next increment of anywhere from four to eight systems. Then, this is planned to be a program of record where the quantities will be significant. So, I think to claim full TRL 9, that's the last box that we need to check.

Yeah, for the low power 15-kilowatt systems, because we've already deployed so much, that's firmly TRL 7 or TRL 8, depending on who you talk to. Then the DE M-SHORAD Stryker mounted system is just behind it, between TRL 6 and TRL 7. The only difference with the Stryker is it hasn't deployed overseas, and it's had limited warfighter use in comparison to those lower power systems. But we're well on our way to TRL 9, like Michael said.

So you mentioned that you've got four in build now for DE M-SHORAD, and those will be handed over next year?

Actually this year—in 2022. This fall, we will deliver those systems to the U.S. Army, and they're going to take them over to an Army base and start training soldiers for potential deployment. They haven't told us exactly what they're going to be doing. 

We design and build all those systems here in McKinney, Texas. We just built a pretty amazing clean room factory where we can do four parallel builds all at the same time. Raytheon Technologies has invested hundreds of millions of dollars in factory capacity in order for us to be ready to meet the need for high energy lasers. 

You mentioned trying to get away from the "It's always five years away paradigm," so forgive me. But assuming all goes well with the current, the anticipated round of testing of these four, what's your anticipated timeframe for seeing these systems as part of the standard deployment package for, let's say, a US Army Brigade Combat Teams (BCTs) in conflict zones? Clearly you're at four simultaneous build capacities right now. Were you to transition over to mass production, that would need to increase. But what are the remaining regulatory hurdles to go through? How fast could you theoretically scale up production if all goes well?

I think we've definitely scaled up for production. I think the facility we have here is unlike anything in the world with regard to building laser weapon systems. Our beam directors also share a lot of common build processes and components with our ISR product line that is building hundreds of units. So I think a big chunk of that production scale-up has already happened. We’re ready.

As far as how quickly the US Army is planning on fielding these, they've been very clear that they want what they call combat prototypes with residual combat capability. So they're not shying away from deploying these first four systems as soon as they get them and get soldiers trained up. 

And then we go from there.

Rather reminiscent of the Red Alert 2 games of my childhood!

In terms of magazine capacity, so to speak, I’m guessing that there is an onboard generator capability in terms of refilling capacitors, but that'll probably be competing with the parent vehicle’s range on internal fuel… Roughly what are the ballpark magazine size and prolonged periods of firing figures that you are aiming at with DE M-SHORAD at the moment?

So a couple things on magazine depth. Let's say your laser system has a 300 second magazine, you're not going to shoot for 300 seconds continuously. If there's a group two drone, you're going to shoot for a few seconds to kill it. Time on target depends on a lot of factors, but after that shot you're laser-off until the next target.

In that time that you're laser-off, the system will be trickle charging to recharge your battery. So it's a very different concept than, say, a magazine clip. In a magazine clip, you're not adding bullets to the magazine while you're firing. But in a laser system, that is certainly a CONOP that you can and do employ.

But if you've got about a 300 second magazine and let's just for simplicity say that each shot is five seconds, then you're talking about 30 ...wait.

You’re doing math in public! You've got dozens and dozens and dozens of shots.

You’ll have 60 shots, right? So that's a huge number, and that does not include doing any trickle charging or recharge of the system. That makes HEL a really affordable option to rapidly defeat UAS and RAM threats. The number of shots is near infinite as long as you have fuel, so logistics and costs are minimal The cost-per-shot is near zero, making it an affordable alternative to traditional munitions. And on top of that you’ve got precision accuracy with very little risk of collateral damage. 

There will always be a role for missiles. Lasers don't replace missiles. They augment missiles. So you save your missiles for the long range, all weather engagements that you really need them for, and you use the laser to sweep up everything else. 

Then lastly, there's just the opportunity cost of running out of munitions. No matter what the cost, even if they're Patriot missiles, you can't afford to burn three missiles on three drones and have a fourth one fly into your radar. That's just not the way air defense works. It's a zero-sum game. You must defeat your threats. So, the real value with the laser is that deep, rechargeable magazine, even leaving cost aside, because then your warfighter is not running out of bullets.

In pretty much every modern conflict, including current ones, there has been a lot of use of what would traditionally have been seen as SHORAD systems in direct fire ground roles, or even indirect roles. Clearly indirect fire is not possible with laser weapon systems, because they are, by definition, a line of sight system. However, do you think there is some scope for multi-role or multi target capacity for laser weapons systems, or is this a system which potentially sacrifices some of that multi-mission flexibility for being really efficient at the core SHORAD mission instead?

Traditionally, especially with new systems like this, we build these systems with a purpose in mind. In this case, counter drone and counter rocket, artillery and mortar defense. But when the soldiers get the systems and especially when they field them, and they're out in the real world, they find new and creative uses for the technology. So I think, yes, it is developed for a somewhat narrow focus. But we've already seen some, I don't know what you would call it, but lateral missions or different applications.

Yeah. You're firing silent, invisible beams of light to kinetically destroy things or burn holes in things at way beyond visual range. There are a lot of great potential applications for that. There are all sorts of different missions that that laser effector can do.

But the other thing about DE M-SHORAD, like Michael said, is it has a built-in advanced radar. It also has a built in advanced electro-optical/infrared sensor (EO/IR), and so the original name for DE M-SHORAD was MML. It was a multi-mission high energy laser because it's doing radar, optical sensing, ISR, intelligence surveillance reconnaissance, battle damage assessment and destroying all sorts of targets all in one vehicle.

Presumably, it's also not necessarily a piece of kit you would want to get too close to direct shell splinter damage and things like that? I can imagine that shrapnel and optics probably don't mix any better in the laser environment than they do in any other environment.

That's right, but it’s important to consider that the beam director is based on a very tough, battle-hardened MTS system that can take a real pounding. We've got some protection for the beam director that you can have in place when it's not in use. 

But going back to what Evan was talking about, when we first deployed these systems, we weren't really sure how they were going to use them. It turns out most of the time they're being used as an ISR asset because you have this incredibly powerful ISR capability, even if you're not firing the laser. 

If you think of the lifetime of a rifle, probably 99.999% of the time it's not actually firing. But unlike a rifle, our HEL actually has tremendous ISR capability and utility when it's not being fired.

In terms of the potential mission set growth that you see beyond the SHORAD mission in the Army, do you think that's going to be primarily driven by user experimentation within the SHORAD vehicle set, or do you see a relatively rapid expansion into other types of dedicated laser vehicles? Do you think it's going to be seized upon as a new part of the arsenal in other mission sets?

There was a time decades ago when radar was invented and they thought radar was going to be just for very specific things. Now there's a radar of some description on almost every platform. Then that even happened with EO/IR sensors. At first, only certain agency drones had great sensors on them… Now we're looking at EO/IR sensors on every platform in the inventory because the warfighter gets used to having these things, needs them for the modern environment, and then can't live without them. I think that eventually we're going to get to a point with high energy lasers. 

So we spend a lot of time looking ahead, but the thing we’re most excited about is that our systems have been put to the test, they’re ready, and we’re building them for delivery today. 

Those asymmetric threats out there are real. And for the first time ever, the high energy laser weapons we need to address those threats are no longer five years away.

Made possible with support by Raytheon.

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