When war changes, it usually changes slowly. We’re used to military technology advancing in predictable, plodding steps – incremental advances on what went before, with one side spending years developing its new plane, or tank, or missile, the other side simultaneously developing ways to undermine it. The first nation builds a thing, the second builds a thing to make it irrelevant, and so the gears of the military-industrial complex keep on a-grinding.
But from time to time, you get a step change – something that suddenly and dramatically shakes up the ways in which people try to kill other people, or stop other people from killing them. In the Second World War and Cold War, it was nuclear weapons. In the 2000s, it was drones. In the next decade or so, it may very well be the directed energy (DE) weapon – a collection of bleeding-edge defensive technologies that, proponents argue, could make whole swathes of conventional weapons economically unviable and functionally obsolete. Directed Energy weapons, particularly Laser Weapon Systems (LaWS), are being trialled on ships, trucks and aircraft, and developed by militaries around the world including the US, China, Russia and the UK.
But after almost 800 years of gunpowder (and 40 years of Star Wars films), what is it about lasers that’s getting modern militaries so charged up today?
What can a modern laser weapon do?
One of the real game-changing advantages of high-energy lasers (HEL) is the non-existent delay between pulling the trigger and hitting the target. Trying to hit something at range with a bullet requires your operator or the weapon’s targeting system to lead whatever it is you’re shooting at. Missiles tracking a moving target have to correct their course in flight. A laser, moving at the speed of light and having no mass, has to do neither of those things – the ultimate point-and-shoot weapon.
That makes hitting targets in the air – drones, aircraft, missiles and artillery – much less of a computational headache. It also makes directed energy weapons the perfectionist’s weapon platform. For all the collateral damage that they do, militaries (and western ones in particular) spend vast amounts of money on precision. As King’s College London’s Jack McDonald told us in our September 2015 drones feature, the combination of advanced optics and laser-guided weapons are basically an attempt to turn drones into “intercontinental sniper rifles”.
For all that expense, though, a missile is still a missile, and missiles aren’t choosy about whom they kill once they explode. A laser, by comparison, produces no shrapnel, and can focus all its destructive power on a pinhead. For example, here is a video from a 2009 test of Boeing’s Advanced Tactical Laser (ATL), in which a beam fired from a converted C-130 cargo plane burns a hole through the engine of a truck.
For comparison, here is a second video from Lockheed Martin, showing how you achieve the same result with one of its Hellfire missiles. Spot the difference.
Finally, however tightly you cram missiles and bullets into a vehicle or a conventional weapons platform, you will always eventually come up against a hard limit when you run out of space. Directed energy weapons don’t have that problem – and if the threat you’re facing is, for example, a swarm of cheap drones, boats or missiles, that problem is a serious one.
“If you have a drone swarm coming at you, you’re just not going to have the physical number of munitions in your arsenal [to defend yourself],” says Elizabeth Quintana, senior research associate and director of military sciences at the Royal United Services Institute (RUSI), of the constraints of conventional weapons. “Even if you did and you fired them all off, you’re going to be bankrupt by the end of the first wave. The Israelis have faced this with their Iron Dome missile defence system. They can very successfully counter most of the rockets that are fired at them, but the cost of it is astronomical.”
But lasers must be astronomically expensive, too, right?
Actually, no – but there’s a good reason that people mistakenly assume they are.
During the Cold War, when both the US and the Soviet Union were throwing bushels of money at anything that looked like it might one day help to shoot down incoming nuclear missiles, the US Air Force came up with what might be the most Cold War-y idea ever. Why not have a fleet of converted 747s on constant standby, armed with huge lasers that could target Soviet intercontinental ballistic missiles as soon as they launched?
The answer was, among other things, the catastrophic price tag. And with the project’s cancellation, the idea of lasers and high cost got lumped together in the public consciousness. But in the decades since, the technology has been miniaturised to the point that a working laser system can now fit onto a large truck, or a ship like the USS Ponce (no sniggering), which has already demonstrated its ability to shoot down airborne drones.
And once you take out all the R&D costs, you end up with a surprising truth: laser weapons are actually incredibly cheap to run.
Defending a ship or a forward operating base against attack is expensive. Missiles are expensive. The lead wall of bullets needed for effective C-RAM (Counter Rocket, Artillery and Mortar) capability is expensive. But a high-energy laser could be fired after a whip-round by a ship’s crew. The ‘cost-per-shot’ for an HEL, as estimated by the US Navy, could come in at under a dollar.
And once a defensive countermeasure becomes that cheap, it fundamentally shifts the cost-benefit analysis of attacking an adversary in the first place. If you’re shooting down X-hundred-thousand-dollar drones or missiles for less than the cost of a half-pint of milk, attacking your military assets becomes like playing roulette on a table with one red, one black, and one hundred thousand green squares on the wheel.
“Cost in itself can be disruptive to an adversary, in the sense that if you are fielding a technology that’s obviously cheaper to field than conventional weapons, your adversary has to find ways to counter that,” says Richard de Silva, writer for defence learning portal, Defence IQ. “If you can fill a capability and your adversary financially can’t meet the requirement to meet you on the battlefield, you’ve beaten them without really lifting a finger.”
The absurdly low cost of HEL also means that, in the wars in which the west is currently involved, we would no longer be flinging out four or five-figure sums’ worth of hardware to counter threats that could be cobbled together for a thousandth of the price - a vast skewing of resources that has dogged modern militaries in conflicts from Afghanistan to Iraq to Syria.
“Most non-state actors have capabilities that are cheap as chips, because frankly they don’t have the resources to develop anything more sophisticated,” says Quintana. “And yet, we are using missile systems worth tens if not hundreds of thousands of pounds. Cruise missiles are being used against ISIS and other jihadi insurgents in Syria – [and] they’re half a million each. So, you know, that’s fine, but after a while you are going to run out of resources to wage these kinds of wars.
“If you can develop a system where the cost-per-shot is more comparable to the types of threats you’re facing, then that is a very attractive proposition.”
So what is the catch?
When defence contractors hawk directed energy weapons, the marketing overwhelming focuses on their use for defence. DE is great at protecting military assets from attack. The problem is that, like almost any defensive technology, it wouldn’t take much ingenuity to make DE into an offensive weapon – with results that might well make the public queasy, and support for such weapons waver.
The first and probably most infamous examples are less-than-lethal DE weapons – ‘pain rays’. The US and China have both put funding into researching these weapons, which penetrate a minute distance under a person’s skin, and make that person feel like they’re on fire.
But on the battlefield, a key concern has been the potential use of DE weapons not to kill, but to deliberately blind.
“[Blinding] was first brought up in the 1980s, when lasers started becoming more viable, and people realised they needed to start legislating these things,” says De Silva. “In the same way that we don’t want anyone shining a laser pointer into the air and blinding an airline pilot, a vast majority of nations have signed the Protocol on Blinding Laser Weapons, saying they will not use any laser to try and injure or blind [as its primary] use.”
But questions of bad PR aside, this reluctance to use precision weapons that may blind in place of kinetic weapons that will almost certainly kill brings up an interesting, if grisly, moral quandary.
“There is some discussion now about whether it is better to be blinded or dead,” says Quintana, drily. “You know, ‘if we can’t [risk blinding] them, we’ll just use a missile instead’… The idea that it’s ‘more legal’ to kill someone than it is to blind them is a rather silly argument, but that’s where we are at the moment.
“Any [weapons system] you develop could be used in an offensive or a defensive capacity, depending on how you choose to use it… Everyone’s seen Star Wars, and everybody worries about the potential for laser systems to be used in an offensive manner. So of course, the applications that have been discussed so far are defensive in nature, because that’s more politically and publicly palatable than using an offensive system. But the reality is that you could [directed energy] either way.”
The future’s bright. And really hot.
With the overwhelming emphasis on DE for defence and the obvious question of how you power energy weapons in adverse battlefield conditions, we’re a long ways off the sci-fi future of soldiers on the ground blasting each other with laser rifles (“all of these things have to be integrated – if you can’t charge your phone, let alone your rifle, that’s a major issue,” says De Silva). But the promise of a defensive weapon that can quickly destroy multiple targets for pennies on the dollar is, says Quintana, “a revolution in military affairs”.
And as with any revolution in military technology, once one nation shows directed energy weapons to be both powerful and cost-effective, there will be an explosion of proliferation. As is the case with drones and as was feared would be the case with nukes, once one country grabs hold of a game-changing weapons system, others scramble to catch up.
Science fiction, then, has got lasers backwards. By making an attack on another country economically and militarily disastrous, directed energy has the potential to make whole areas of modern warfare unthinkable - and perhaps make us safer as a result.
Elizabeth Quintana is a senior research fellow in air power and technology, and director of military sciences at RUSI. She is the co-author of the paper ‘When Will Directed Energy Weapons See the Light?’
Richard de Silva is a writer on defence and security at Defence IQ, and is head of online content. He is the author of the paper ‘Directed Energy Systems: Analysing the Myths and Misconceptions’. Defence IQ is a partner in the upcoming Directed Energy Systems conference, which runs from February 24-25th in London.