The rise of laser warfare

In April, the U.S. military deployed a pair of high energy lasers to combat enemy drones.

Now that the once-imagined weaponry of science fiction is reality, how will it impact the future of warfare?

Today, On Point: The rise of laser warfare.

Jared Keller, managing editor at Military.com. Author of the recent WIRED article “Welcome to the Laser Wars.”

Masao Dahlgren, fellow with the Missile Defense Project at the Center for Strategic and International Studies (CSIS), where he writes on missile defense, space and emerging technologies issues.

Stuart Dee, research leader in the defense and security research group at RAND Europe.

Part I

WAR OF THE WORLDS: Wait a minute, something's happening. I can make out a small beam of light against a mirror. There's a jet of flame springing from that mirror and it leaps right at the advancing men. It strikes them head on. Lord, they're turning into flames. Now the whole field's caught up by the woods of barns. There's gas tanks of the automobiles spreading everywhere. Coming this way now, about 20 yards to my right. Oh, the broadcast got suddenly cut off. That was October 30th, 1938. The day Martians invaded Earth.

MEGHNA CHAKRABARTI: Oh, the broadcast got suddenly cut off. That was October 30th, 1938. The day Martians invaded Earth.  That is, in Orson Welles' legendary radio broadcast, “The War of the Worlds.” Based on British author H.G. Wells' 1898 eponymous novel, the invading Martian machines obliterate much of humanity by spreading a deadly weapon called the “Black Smoke."

WAR OF THE WORLDS: This is the end now. Smoke comes out. Black smoke drifting over the city. People in the streets see it now. They're running toward the East River, thousands of them. People are trying to run away from it, but it's no use. They're falling like flies. Now the smoke's crossing 6th Avenue, 5th Avenue. A hundred yards away. It's 50 feet.

CHAKRABARTI: Orson Welles' 1938 radio broadcast famously caused a mass panic. Americans across the country believed the Martian invasion was real. And given what people are prone to believe these days, it doesn’t surprise me at all that Americans in the '30s could believe that aliens had landed. Especially since the science fiction of “Black Smoke” was actually already science fact. The world had seen real chemical weapons, such as chlorine gas, choke thousands of soldiers to death in the First World War.

Now, H.G. Wells’s novel was also more than 60 years ahead of its time in its depiction of another weapon ... “heat rays” that incinerated flesh and bone humans. Actual laser technology didn’t come into existence until 1960, but as soon as it did, lasers soon became the weapon of choice for the rest of the science fiction world:

(MONTAGE)

FROM STAR WARS IV: “This is the weapon of a Jedi Knight. Not as clumsy or random as a blaster. (LIGHTSABER) An elegant weapon but a more civilized edge.”

FROM TERMINATOR 2: “Survivors of the nuclear fire called the war ‘Judgement Day.’ They lived only to face a new nightmare: a war against the machines.” (BOMBING AND LASER)

FROM STAR TREK THE UNDISCOVERED COUNTRY: “Why not simply vaporize them? / Like this? / (LASER AND ALARM)

FROM X-MEN APOLCALYSE: “You can open your eyes, Scott. There’s nothing to be afraid of. It’s quite – (CYCLOPS BLASTS EVERYTHING) Get back!”

CHAKRABARTI: I do love science fiction. But here today, we're here to talk about how laser weapons and laser warfare may be crossing over from the realm of fiction to real-life warfare. That's because the Department of Defense has invested about a billion dollars every year on “directed energy” programs – that's an umbrella term that encompasses microwave and laser weapons.

And this April, the U.S. Army deployed a pair of high energy lasers to disable enemy drones … marking the U.S. military’s first publicly acknowledged deployment of a working energy weapon for air defense outside of testing.

That's what we're going to talk about today. Are we at the dawn of the era of laser warfare? Jared Keller joins us. He’s the managing editor at Military-dot-com. And he recently authored an article for WIRED Magazine titled “Welcome to the Laser Wars.” Jared Keller, welcome to On Point.

JARED KELLER: Great to be here.

Thanks for having me.

CHAKRABARTI: Okay, so let's talk specifically about the system that was actually deployed. It was called a Palletized High Energy Laser, is that right?

KELLER: That's correct. And it's based on what's called the LOCUST Laser Weapon System developed by Virginia based defense contractor BlueHalo.

CHAKRABARTI: Okay, so what is a Palletized High Energy Laser?

KELLER: The best way I can describe it is it's basically a giant box, a giant energy producing box with a directed energy array on the top. They're designed for fixed site defense, so rather than being strapped to a vehicle and driven around a battlefield, they are stationary. And the goal of the system is relatively simple, to knock incoming enemy drones and missiles out of the sky, using a directed beam of highly energized photons.

CHAKRABARTI: And so this was acknowledged in April of this year. That's when your article came out, but in your reporting, it says that they may have been deployed as early as November, 2022.

KELLER: That's correct. The deployment was only recently disclosed by Blue Halo in a press release, which is how I learned about it.

But additional reporting indicated that the systems had been operational overseas for at least a year. And based on other comments from senior army officials, they've actively been shooting drones out of the sky.

CHAKRABARTI: Wow. Okay, so how much do we know about how it actually functions, right? Because high energy can mean a lot of things.

Is it infrared? Is it electromagnetic? What is it?

KELLER: The core of the system is relatively elegant in its simplicity, using a tremendous amount of energy. The system basically excites photons and throws them at a target so that you're bombarding a specific area of a drone or missile with heat.

As opposed to a flash of light and a pulse of energy that you might see in science fiction, the system is virtually silent and the beam of of energy is invisible. The only indication that you've actually engaged target is when sparks and flames start to pop out of it.

CHAKRABARTI: Oh, wow. Okay. Has the DOD confirmed publicly that any drones have actually been shot down with the weapon?

KELLER: So direct inquiries to the army have yielded minimal results. They typically cite what's called operational security when discussing the deployment of new weapons systems overseas. However, Doug Bush, who's the army's top acquisition chief, recently gave an interview to Forbes where he indicated that these systems had been effective in some situations. Indicating that yes, they had indeed encountered adversary drones, deployed overseas and succeeded in neutralizing them before they hit their target.

CHAKRABARTI: Okay. I want to just preface the next question with, I know that the DOD rarely ever gives specifics, right? But I'm still, I'm just curious, right? Do you have any triangulation on where the system has been deployed?

KELLER: DOD officials have been speaking for months about the potential application of directed energy weapons in the U.S. Central Command area of operations, which generally encompasses the Middle East. And as we know, drones in particular have become a significant threat to U.S. troops, not just deployed to Iraq and Syria, but also to U.S. Navy warships in the Red Sea, based on the threat from Houthi militants in Yemen. My understanding is that if these systems are anywhere, they're likely in the central command area of operations.

CHAKRABARTI: Okay. Now, you have seen a video of the weapon being tested. And in the video, it shows how an operator actually fires it.

Can you describe that?

KELLER: Sure. The system is relatively elegant. I think I already said elegant, but it is elegant. It uses an Xbox controller which is actually a standard operating system for a lot of next generation U.S. military weaponry. Either they use a commercially available video game controller, or a militarized version called the full motion control unit.

But these systems are designed for a generation of war fighters who have grown up playing video games. So you have a standard control, it's got two joysticks and a bunch of buttons, and the system analyzes incoming targets, locks on, and then the operator pushes the button, enabling the laser to take out the incoming threat.

CHAKRABARTI: Wow. Okay. So how long has this blue halo lead development been in process?

KELLER: About five years. The company was formed from the conglomeration of several other defense contractors in 2018. And the company has really succeeded in accelerating the development of laser weapons, primarily because they weren't relying on DoD contracts.

It's a private equity involved company. So they were able to build a product independently of incremental contracts from the DOD, and then present it to army leaders. And army leaders apparently liked what they saw, because the system is now operational downrange. How long has the DOD been interested in some kind of laser technology for use in the battlefield?

KELLER: Ever since the debut of the laser in 1960, the U.S. military has been interested in it. In fact, most of the coverage of Theodore Maiman, the physicist who invented the laser, most of the coverage of the unveiling of his technology took on the effect of here comes the death ray, invoking another piece of science fiction technology from war of the worlds.

So the laser applications have been relatively focused in recent decades, while in the early years of laser weapon development, the D.O.D. was focused on far-fetched initiatives like the Star Wars initiative, which sought to disable incoming ICBM's with spaceborne laser weapons, the focus has shifted towards air defense, which is the seemingly most practical application of the system.

CHAKRABARTI: And we're going to talk a little bit later in the show about why that is, and particularly because drones are an interesting technology that actually more people than just giant centralized militaries can get their hands on. Do you have any sense as to how much has, I think I said a little bit earlier about how much the United States has been investing in these directed energy programs, a billion dollars a year, is that right?

KELLER: Yes, across 31 individual programs for the last several years. The funding of these programs has taken on a lot of priority, especially as military commanders who operate overseas are recognizing the threat that weaponized drones pose to their forces abroad. In particular, the Houthi threat in the Red Sea has really accentuated this dilemma for military commanders. For the Navy in particular, they're expending million dollar missiles to take out $500 drones. And as commanders have commented in hearings with lawmakers on Capitol Hill, that cost curve is unsustainable.

Part II

CHAKRABARTI: I'd like to introduce Masao Dahlgren into the conversation now. Masao is a fellow with the Missile Defense Project at the Center for Strategic and International Studies where he writes on missile defense, space, and emerging technology issues.

Masao, welcome to On Point.

MASAO DAHLGREN: Thanks so much for having me.

CHAKRABARTI: So what I'd like to do with both of you, first of all, is talk a little bit about other applications already in the military of laser technologies, because that's going to help us understand the difference now with this new weapon system.

I think people might be familiar with, for example, laser guided weaponry already. Can you just tell us a little bit more about what that would entail?

DAHLGREN: Sure. So lasers have been in widespread use in the U.S. military for a variety of non-weapon rules, right? Guidance systems, pointing systems.

They're used for missile dazzlers already on aircraft to defend them from surface to air missiles that might hit them, to blind to the sensors on those missiles. So we've seen a lot of usage there and a whole series of regulations and practices around that. The interesting part is now transitioning to missions like air defense, drone defense.

We were trying to shoot down these big things. We've moved from this big Star Wars concept, strategic missile defense to smaller wars, right? Shooting down these drones that are now ubiquitous across the battlefield.

CHAKRABARTI: So both of you mentioned SDI and I just want to play a clip here from March 23rd of 1983 when President Ronald Reagan announced the Strategic Defense Initiative and that was a plan to protect the United States from intercontinental ballistic nuclear missiles in the face of rapidly evolving capacity from the Soviet Union.

RONALD REAGAN: What if free people could live secure in the knowledge that their security did not rest upon the threat of instant U.S. retaliation to deter a Soviet attack, that we could intercept and destroy strategic ballistic missiles, before they reached our own soil or that of our allies? I know this is a formidable, technical task, one that may not be accomplished before the end of this century.

Yet current technology has attained a level of sophistication where it's reasonable for us to begin this effort.

CHAKRABARTI: That was President Ronald Reagan in March of 1983. Now some of the SDI vision included x-rays and chemical lasers, but Masao, as far as memory serves, we never actually came up with a defense system that used lasers to disable or shoot incoming ICBMs out of the sky.

DAHLGREN: A lot of the work that informed SDI, and other past programs have really informed what's being done now. SDI, a lot of the work that was done was on chemical lasers, right? You would generate the laser beam by mixing really volatile chemicals together. And you could get into a power class that'd be useful for shooting down these nuclear armed missiles. That chemical laser technology later made its way into a program called ABL which would put a laser on a 747 to try and shoot down a North Korean missile. And then finally, now we're moving to a new era of electrically powered lasers.

It's like comparing a steam engine to a Tesla. Instead of mixing chemicals together to generate the laser beam, you'd have a series of diodes, right? What you'd use an industrial laser for cutting metal and fuse them together and use them to generate a beam. So that's the real big change that's happening right now that's defining the future.

CHAKRABARTI: Can we just go back to ABLs for a second? Because that meant, that stands for Airborne Laser System, right? And that was the idea of putting chemical lasers on modified 747s?

DAHLGREN: That's right. And the ABL program was eventually cancelled. It coincided with the financial crisis in 2011. And there wasn't a budget to continue that work, but a lot of the data collected on how to point lasers, on how to cool them down, on how they actually would melt missiles and drones, that wasn't data that existed before, and that data has really informed the work that's going on now.

When I'm thinking about how the DOD is buying new laser capabilities, I'm really worrying about everything but the laser. How do you keep that laser pointed at something that's 200 miles away? It's hard enough to do with your cat three feet away, to keep the laser still. Now imagine keeping it steady on a pinpoint size target 200 miles away, 300 miles away.

That's the problems that we have to deal with when turning this from a science experiment into an actual air defense system.

CHAKRABARTI: Is it actually a problem? I'm asking this from a complete layperson's perspective. But the other sort of laser guidance and laser painting, for example, that you had talked about earlier, that's also done from very far away, isn't it?

DAHLGREN: That's true. But the range classes we're talking about are a little different when you're talking about defending a cargo plane from an incoming missile, within a kilometer, two kilometers, three kilometers, and defending an airbase from drones that might be hundreds of kilometers, tens of kilometers away.

You have to deal with beam direction, right? How do you point that laser? How do you keep that cool? How do you track that target? You have to deal with power. How do you generate enough power for these things and integrate that onto a system where, you know, every pound that you add creates three pounds more fuel that you have to carry with you.

It comes to maintenance; how do you maintain these things? It comes to actually weather prediction. In recent tests and in studies, the range of these laser systems. It goes down tenfold or goes up tenfold, depending on what the weather looks like, what air turbulence looks like and predicting that will really affect the performance of these systems.

So you have to plan for all that, and that's what the Pentagon's trying to get over right now.

CHAKRABARTI: I see. So Jared, let me turn back to you because you've also reported in detail about other programs or attempts to deploy lasers in various formats by the U.S. military. They're just really interesting.

So can we, I want to go through a couple of the ones that you've reported on as well. There was the Army's HMMWV mounted Zeus Laser Ordnance Neutralization System?

KELLER: That's correct. The HLONS, which is a typical DOD acronym, which was eventually deployed to Afghanistan and Iraq to burn landmines and improvise explosive devices and unexploded ordnance out of the way of ground forces.

CHAKRABARTI: And so that actually was used, and was it effective?

KELLER: My understanding was that, as Masao said, the system was very difficult to maintain. There are power considerations, there are atmosphere considerations for coherence. So my understanding is that the success of the system was mixed.

CHAKRABARTI: Okay, and then you also talk about in 2014, the Navy had a laser weapons system that was actually successfully disabling drones?

KELLER: Yes, drones and small boats, and it was tested from the bow of an Austin-class amphibious transport dock, the USS Ponce. I believe the system was referred to as the LAWS, or Laser Weapon System. And the Pentagon billed it at the time, as the world's first active laser weapon system.

Although the Ponce was eventually decommissioned in 2017, and the system was moved on to another warship, which was successfully tested in 2020 and 2021. The Navy in particular has invested heavily in lasers for ship defense. ... But those weapons haven't been deployed in an active combat zone as of yet.

CHAKRABARTI: I see. Okay. So that's the critical difference here. It looks like they've been successful in testing those, you've been talking about and are on just to confirm, are on some naval vessels.

KELLER: Yes, there's one system referred to as the High Energy Laser with Integrated Optical-dazzler and Surveillance or HELIOS, which currently adorns the bow of an Arleigh Burke-class destroyer.

The USS Preble. When you look at publicly released photos of the Preble conducting normal operations in the sea, you can actually see the HELIOS turret on its bow, which is pretty incredible. But there's been no public disclosure that the HELIOS has been used to, say, knock out an incoming drone or an uncrewed fast boat that may be headed to intercept a warship.

CHAKRABARTI: Okay. So I wanted to go through that detailed background of the activity that's been happening in the past 15 or 20 years or so for a specific reason, and that is, as you both pointed out, laser technology first came onto the scene in 1960. And though it was of great interest to basically every military in the world from the get-go, it's not until this more recent period that we've been seeing, the laundry list of programs that have gotten as far as the testing phase. And there's a reason for that. So the question is, what are those reasons and why is there this renewed interest in laser technology now?

STUART DEE: What has changed, certainly in the past two years, probably more poignantly in the last decade, is that the asymmetry of cost between attack and defense has changed very quickly.

CHAKRABARTI: That's Stuart Dee. He's research leader in the defense and security research group at RAND Europe.

DEE: What we've seen in the last couple of years is that attack has become incredibly cheap. So we have examples in Ukraine of scratch teams assembled for comparatively low costs. So there's an example of an entire drone team being put together for about $700,000 that took out Russian equipment worth approximately $80 million. Similarly, there's a proliferation out there of Iranian technology and we're seeing the Houthis in the red sea harassing shipping with large numbers of quite low cost, single use drone technology.

CHAKRABARTI: Dee says that the result of that change is that defense has become particularly expensive in the overall balance of a war.

Currently, the standard Missile 2 used by the U. S. Navy for air defense costs more than $2 million per single shot. Now, Dee says it's not completely clear how much laser weapons will ultimately cost, but there is a general consensus that they will cost less than the current systems in use.

DEE: The relatively high cost associated with conventional, complex weapons, within that, it's not just the cost of the weapon itself.

It's the cost of the research and development that went into it, the control systems, the stockpiling. It's about the entire ecosystem that wraps around it, the intelligent management of the supply chain. And that's where it all fits in. I think what we're probably seeing at the moment is that we don't have quite the same maturity in our understanding of what the cost base for directed energy weapons looks like.

There's an example in the UK with a program where it's been quoted that it's 10 pounds a shot. So what we're probably seeing at this point is that we're basing our understanding of the cost of these new weapons purely on the energy that it takes. It's a very big potential step change in cost, but we might be seeing some quite polarized numbers at the moment.

CHAKRABARTI: That's Stuart Dee. He's at RAND Europe. Okay, Masao and Jared, let's dig into this a little bit because quite frankly, I'm not sure what Dee is providing there, I think he's acknowledging that it's not a total analysis of how much these laser-based weapon systems will ultimately cost, right?

Because are we factoring in the development and the research and all the testing that we know is going on?

DAHLGREN: Sure. There's R&D costs, but we also have to acknowledge that one of the main cost drivers for these systems is the sensors, the sensors used to actually detect an incoming missile, an incoming drone, figure out what it is, and then aim the system to hit it.

Those costs are common, whether you're using a missile interceptor to shoot it down, or a laser or a high-powered microwave. Some of those are going to be pretty similar. But I think he's right in saying that the analysis isn't complete. And when we're looking at the kinetic interceptor side, those missile interceptors that were used successfully, against those Iranian missiles, those costs are also coming down.

We should be thinking about the relative cost of what we're defending. If you're defending a $2 billion ship, with a $200,000, $300, 00 missile, that's not too bad of a deal. And so those kinds of costs also need to be considered when assessing the total cost of a system.

CHAKRABARTI: Jared, what are your thoughts on that?

KELLER: I think Masao's absolutely dead on. Especially with regards to the sensor suite. Maintaining, for a laser weapon to really be effective, you have to maintain time on target for at least a couple of seconds, in order to burn the thing out of the sky. And in order to do that, you need very sophisticated targeting, target acquisition and detection software and that takes, that technology takes plenty of time and plenty of resources to develop. In my reporting on BlueHalo, one of the main points that they've tried to make is that their AI based targeting software is what makes the system as effective as it is. Not only are they able to generate a 20-kilowatt laser beam, but they're able to do so and have it be as effective as, say, 100 kilowatt laser beam. That's their claim.

And a lot of that comes down to targeting software and other technology that enables the laser to lock onto its target.

CHAKRABARTI: How are these things being powered?

Jared, I'm going to start with.

KELLER: A lot of, sorry, with a lot of electrical energy, a significant amount of power. So much power, in fact, that Doug Bush, the acquisition boss of the Army, has stated that systems that are undergoing testing often show up with problems for the average soldier, because they overheat, as Masao said, cooling is a really important element.

But it's a ton of batteries, basically, is the best way I can describe it.

CHAKRABARTI: Masao, do you want, do you have more insight on that?

DAHLGREN: Yeah, though I want to touch back a little bit on a previous point We're talking about these sensors used for laser systems. Actually, when you talk to folks who are prototyping these systems, soldiers, sailors who are using these lasers, the sensors that often come with them, they use for other purposes.

They require really sophisticated cameras. I think there's reporting out there on how they're using that to track small boats just to observe things going on in the Red Sea. And so it's those kinds of knock-on benefits that we should also consider when talking about these systems, but Stuart and Jared are right.

It's everything but the laser. It's the power generation. It's the cooling. It's predicting weather, it's maintenance. It's all that stuff that needs to be matured. The core piece of generating that laser beam with an electrical source, that is rapidly maturing and has enough power for primetime.

CHAKRABARTI: Now, theoretically, with constant maintenance, though, once the technology is matured and the systems are deployed and maintained, again, theoretically. You could, what, get an infinite number of shots out of them, Masao?

DAHLGREN: That's right or at least you'd be limited by your supply chain, your logistics for generating power.

The U. S. Army is investigating a lot of next generation approaches to increasing the power generation on fixed bases, right? They're looking at things from small modular reactors to better and more efficient diesel to biofuels. And so there's a whole range of considerations we need to make that aren't just the laser itself. I think that's the bottom line for transitioning from science to a weapons system.

Part III

CHAKRABARTI: Masao, what other nations do we know are actively developing militarized laser technology?

DAHLGREN: It spans a whole gamut. We know that key strategic competitors Russia, China, have developed and deployed military laser systems. Especially for use in blinding U.S. Satellites. Satellites are, you know, how we get information about the battlefield, how we communicate. We've seen how important they are in Ukraine for communication and they represent a really destabilizing capability. Right? To render U.S. leaders blind in a crisis would be a huge problem.

And so the DOD is doing a lot of work to acquire next generation satellite constellations that are more resilient to these kinds of threats. Those are some developments happening in the adversary space, and our allies are developing these things, Japan among them.

They recognize that the small drone threat really isn't going away. We talk about lasers as a first, right? The first lasers deployed in the Middle East. The other first is that it's the first time a U.S. service member has been killed in an enemy air attack in decades, right?

Out in Jordan, drone attack slipped through and killed two two warfighters, two service members. And that reflects the urgency and ubiquity of this problem set.

CHAKRABARTI: And Jared are there, so Masao mentions Russia and China. I think you've reported on a couple of others.

Correct me if I'm wrong, but like countries like Turkey even?

KELLER: France, India, and Turkey, according to the RAND Corporation.

CHAKRABARTI: Okay. So I guess what I'm wondering is, does putting all this together, it does seem as if the world is turning a corner on the active use of laser technology in warfare, Jared.

Is that a fair assessment?

KELLER: I think so, for a couple of reasons. It's not just a matter of the technology being mature enough. To actually be functional on a battlefield and in chaotic circumstances, which remains to be seen with additional testing. As Masao has mentioned, atmospheric conditions, maintenance, all of those factors will end up determining whether lasers become a ubiquitous fixture of battlefields of the future.

But it's also a matter of need. The rising drone threat in the last several years has put the U.S. and its allies on their heels with regards to air defense, and the attack in Jordan that killed 3 service members was a wake up call. Maybe not the wake up call, but it was part of a long waking from a slumber.

Let's say, and as a result, we see our allies pursuing this technology as well. The UK Royal Navy is moving up the employment of its DragonFire high power laser onto a warship by four years, explicitly citing the threat from Houthi rebels in Yemen and House Republicans in their long delayed security assistance package.

For Israel included $1.2 billion for the development of the iron beam laser air defense system to counter short range rocket threats from Hamas militants. So it's not just the U.S., but our allies as well are investing heavily in laser air defense.

CHAKRABARTI: And since we've mentioned the service members that were killed in that drone attack in Jordan, just to say their names.

They were Sergeant William Rivers of Carrollton, Georgia, Specialist Kennedy Sanders of Waycross, Georgia, and Specialist Breonna Moffitt of Savannah, Georgia. That happened in January. I wanna, we have to be frank in talking about the potential downsides here. Also of this technology, because no new weapon system comes with only infinite upside.

Masao, what are the potential not just dollar costs, but logistics, practical costs, what errors could be made with systems like this? What do you think?

DAHLGREN: So I think there's a lot of operational challenges that need to be worked out. We saw those kinds of challenges with the ABL system.

ABL generated a laser beam that was able to shoot down a missile. The problem was logistics, dealing with those chemicals that have to go on a 747. Dealing with the air turbulence buffeting around the plane that defocuses the laser. We're gonna face similar challenges when we're pushing for this whole stack of technologies.

I mentioned weather before, but that's going to be enormous. In operational testing, weather conditions dramatically affect the performance of these systems, and so that affects an entire stack of planning tasks you have to do if you're an air defense operator in the army, you have to now think about where you might place these to avoid certain weather conditions.

You might have to think about how you mix lasers, high powered microwaves and traditional kinetic defense systems to provide coverage of a base on certain days. You might have to rotate things in and out. There's a whole suite of considerations that need to be figured out, and that's been the biggest challenge, right?

The laser itself is rapidly maturing, but it's everything outside of that. That's a challenge.

CHAKRABARTI: Jared, in your reporting again, you describe video footage of one of these laser air defense systems working and you say in the video, you can see that a drone, at some distance away, suddenly things spark and does it catch on fire and then just fall out of the sky, essentially?

KELLER: That's absolutely correct.

CHAKRABARTI: So would, ostensibly, a similar thing happened to any object in between the laser system and the target drone?

KELLER: That is a potential problem. The issue is, for I think a lot of people thinking about, broadly, about the nature of warfare is what happens when that object between the laser and its target happens to be an enemy combatant and how are we addressing those challenges there?

CHAKRABARTI: So I guess what I'm just, again, forgive me if these questions sound like very elementary, but we're talking about cutting edge technology. But there's essentially, once you fire the laser, there's no way to control its effect on anything that comes in between the system and the target.

KELLER: Essentially now you can basically cut power and eliminate the beam. Should something come between the laser and its target. But no, it's a destructive beam of energy that's traveling across the battlefield. And it's virtually invisible too, so the potential of someone to say stroll between the line of sight between yourself and the target is, that's a potential problem.

CHAKRABARTI: Now, are there any at all international agreements on the use of this kind of technology in warfare? Jared?

KELLER: So there's a 1995 provision from the UN that prohibits the use of lasers for blinding purposes. So to permanently blind an adversary combatant, that's prohibited.

But in terms of actually using laser weapons for offense purposes, targeting, say, an enemy soldier, it's not necessarily prohibited. There are prohibitions around dealing out undue pain and suffering in the course of combat, but there are some debates around whether that really applies to laser weapons.

So really, the only prohibitions are around using lasers for blinding purposes, which is a major problem.

CHAKRABARTI: Masao, do you think that, again, I think these are important sort of ethical questions to ask with the advent of any new technology that's used in warfare, because usually we've done it retroactively, right?

It was after the intro, thinking back to how we started the show, it was after the use of widespread chlorine and other chemical weapons in the First World War that we began as a planet thinking more specifically on bans or prohibitions against chemical weapons. Should we be more proactive when it comes to new technology like laser weaponry?

DAHLGREN: I think you have to consider not just the newness of a technology, but the use case and the purpose. Kevlar is new technology. It was new technology at one point. But its purpose was fundamentally defensive, right? It helped us defend our bodies, our troops, our vehicles, right?

And so the most immediate cases for these weapons to me are defensive, right? How we think through that. You mentioned laser, things coming between a laser and the target. I think those issues apply with kinetic weapons right now and have been mostly resolved. I'm actually more concerned about safety for what happens behind a target.

These continue on after you hit something and so you could end up hitting a satellite by accident, and so you have to do careful planning. You might have to do computer simulation to figure out before you do an engagement whether you're going to hit another satellite, another plane. The reflections of these lasers, they're so powerful that even looking at the reflection of the laser could permanently blind you.

And so how do we think out those safety considerations? I think that's going to be a major challenge moving forward.

CHAKRABARTI: So can I just jump in here? Because that's a really good point. Again, just trying to understand how this technology works. Ostensibly, once the target is hit by a highly directed beam of energy like that, some of the energy has to dissipate, but not all of it.

Is that what you're saying? That it can continue on? For what? How far?

DAHLGREN: It can, it will continue on but it will slowly be defocused, right, by the atmosphere and other things and also just physics, lasers will eventually diffract, and they'll be less powerful. But yeah, the main consideration here is friendly fire toward satellites, now we have a robust body of military law, concepts of operations rules of engagement on lower powered lasers to avoid these kinds of things, right?

Lasers are in frequent use in the military that can blind you, and so we have eye safe measures. The question is, how do we scale those up? How do we reconsider them for these extremely high-powered laser systems?

We've been speaking about this publicly acknowledged deployment in terms of air defense, but obviously one has to wonder, Jared, do we know if offensive capabilities are already being developed for laser technology by the U.S. military?

KELLER: In the past, they have. I believe in the early 2000's, there was a program that was aptly titled PHASR which focus on using a low yield laser weapon to temporarily, not permanently, but temporarily blind enemy adversaries and have them basically stopped in their tracks. My understanding is that the Air Force discontinued research on the project, because not only was it not really functional on the battlefield. It was a huge, bulky rifle-like object, that applying those gets into questions of power and logistics. But the accession of the U.S. to the U.N. provision on blinding lasers in 2009 made the research into that project move.

CHAKRABARTI: Yeah, the reason why I ask that is the two major world wars in the 20th century have always been so instructive to me in terms of how quickly military technology can change, right? Because we went from prop engine planes in the First World War to putting nuclear weapons on a bomber and bombing Japan with a nuclear weapon in the Second World War.

And that was, they were only a couple of decades apart. So it's just, it challenges my imagination to think that militaries around the world wouldn't want to somehow move back towards, or not back, but move towards a more functional system, the 747 idea that we talked about a little earlier.

So Masao, your thoughts on the aim towards developing offensive capabilities for laser weapons?

DAHLGREN: I think the limiting factor here is that lasers are a line-of-sight weapon and this is really simple, almost elementary, but they travel in a straight line, they're limited by the curvature of the earth, how far you can see to the horizon if you're standing on the ground, that's not very far.

If you look at the casualties, most of the casualties in Ukraine and other large conflicts, right? It's mostly from non line of sight weapons, artillery, things that shoot past that curvature of the Earth, past the line of sight that you can't even see. I think their utility is gonna be lower, when you're talking about shooting laser rifles at each other on the ground.

I think the main application in the near term and out for the next 10 years is going to be air defense. But these are things that are changing every day. And curious to see how technology changes.