In recent years small drones have gone from being toys and photography tools to a deadly threat on the battlefield. Kamikaze drones have become especially prominent in the news due to their use in the war in Ukraine by both sides. While we haven’t seen coordinated swarms being actively employed on the modern battlefield, it’s likely only a matter of time, making drone swarm defense an active field of development in the industry.
The US Air Force Research Laboratory recently conducted tests and a demonstration of an anti-drone weapon that uses pulses of high-power microwave energy to fry the electronics of a swarm of drones. Named the Tactical High-power Operational Responder, or THOR (presumably they picked the acronym first), it’s housed in a 20ft shipping container with large microwave antenna on top. The form factor is important because a weapon is only useful if it can reach the battlefield, and this can fit in the back of a C130.
THOR likely functions similarly to a shotgun, with a relatively large effective “beam.” This would have added advantages like frying multiple drones with one pulse and not needing pinpoint tracking and aiming tech required for projectile and laser-based weapons. Depending on its range and directivity, THOR might come with the downside of collateral damage to electronics close to its line of fire.
Drone swarms are of course the other side of this arms race, but fortunately they also have non-destructive uses like lights shows and perhaps even 3D printing.
39 thoughts on “THOR Microwaves Drone Swarms”
Is it wrong to want a THOR of my very own?
Frequent low flying helicopters in my area make this sort of thing tempting on a regular basis.
A 2D array of magnetrons and a wave guide to phase match them into a single beam. Maybe add a cavity and make a pumped maser, gamma ray version. :D
If only electricity wasn’t so expensive and high wattage microwave ovens were so hard to find these days.
Depending on what kind of helicopters, you might be disappointed with your return on investment! In our machines the only semiconductors you’re likely to find are the diodes in the rectifiers or the pilot’s tablets XD
Good point, no doubt they’ve anticipated ways to cope with far more wattage than my fusebox could muster, even with a three phase supply.
Still, I wonder how the robot dogs would fair.
I dread the day a couple of thousand of the things come galloping over the brow of a hill armed with machine guns and mini rockets. :D
I lived in a tall apartment building and didn’t think much about leaving the blinds open. Imagine my wife’s surprise to wake up to a drone hovering outside the bedroom window. I actually spotted the creep kid on the roof of a nearby parking garage. Despite really, really (really!) wanting to resort to violence or simply shoot it down with a BB gun, if it fell on someone or someone saw some dude shooting a “gun” off a building it would be me having to explain stuff to the cops.
I needed a THOR.
Couldn’t this also down conventional craft (including airliners or fighterjets)?
I would guess likely not, as electronics in a larger aircraft are generally more hardened/shielded. The aircraft skin is going to act as a faraday cage. And of course the military doesn’t seem to want to talk about the effective range, but given how they talk about how fast it tracks, I’m guessing its designed to be used at medium to short range. A long range weapon wouldn’t require high speed tracking.
I’m absolutely not a military arms expert though.
To be effective, a faraday cage cannot have any gaps larger than the smallest wavelength of light you wish to block. No idea what frequency they’re using, but microwaves can go down to a millimeter in wavelength, so…
Does it have to be 100% gap free to provide any protection? I’m genuinely asking, I don’t know enough about how it works with high frequencies. So say you have a typical electronics bay which is generally surrounded nearly entirely with aluminum sheets that are riveted together, with only removable access panels and wiring passthroughs (behind non-connecting skin) as gaps. Would that block some of it, or none?
There must be a reason this tech hasn’t been thought to have been deployed against full-size aircraft in the past, from what I can tell it’s not exactly bleeding edge. Something about drones must make them particularly vulnerable to this sort of attack.
Yes, they fly orders of magnitude lower and slower. That’s what makes them vulnerable. Direct energy weapons have been used against fast jets before: lasers designed to blind the pilot. To my knowledge there’s never been an energy weapon system to damage the aircraft itself, it’s a hard thing to do from the fortune.
My other comment is meant to say “hard to do from the ground”.
The aircraft skin would act more like a brick wall than a faraday cage, massively attenuating the signal due to the poor penetration capabilities of microwaves. However, any gap larger than a few millimeters would allow the microwave radiation through, potentially causing glitches in the hard circuitry itself.
The reason we don’t tend to use microwaves as weapons like this is manifold – they’re easily scattered and attenuated by weather, because they’re not coherent like in a laser or maser they require massive amounts of power to achieve any sort of usable range, and because leaking or backscattered microwave radiation can be very dangerous to people on the ground, in the right circumstances.
We can reasonably estimate the wavelength based on the size of the antenna, can’t we?
Agree. Assuming that container also includes a generator, no bigger than a few tons, as the power source (as I can’t imagine being grid connected would be viable as a battlefield weapon). And even assuming a low duty cycle, my guess is that it’s useful range is 100s of m, maybe up to a couple of km. It’s not going to touch anything at normal aircraft altitudes.
Wouldn’t a faraday cage around the electronics of the drone render this completely useless?
Well it needs to receive command and control, as well as positioning signals…
Now a crafty HaD reader could probably build an autonomous system to fly by, say, camera sensor. Such a drone is much more complex than an off the shelf consumer piece of kit, but yes… in such a setting one would render this microwave useless
Not an expert but I suspect that if this weapon is not deployed in 4s you can sent out some recon drones and maneuver around it destroy it and THEN deploy the swarm.
Not sure how quick this beast can turn but drones fly at 120km+ speeds nowadays…
Exactly that, and I guess military drones are also much faster than that. The hardest part IMO is not the beam generation, but matching the target speed and direction, hoping it doesn’t engage in semi-random evasive maneuvers, or employing impossible amounts of power to shoot multiple beams in the hope the target will fly into one.
Assume extreme tracking speed, something like the CWIS spins at 115º/s, especially with a wide beam you wouldn’t be dodging it at low altitude. Its hard to say what kind of power output this thing has, based on the enclosure that generator produces less than 3kW, but batteries/capacitors and short bursts could raise the beam output. I do agree though, pitch angle doesn’t look fantastic, I would suspect this is susceptible to attacks from above; combined with radio jamming this would work the first/couple times before an attacker would adapt by programming drone swarms to dodge high on a loss of communication.
In fact, you would probably see drone swarms specializing in targeting this kind of equipment.
‘THOR likely functions similarly to a shotgun, with a relatively large effective “beam.”’
Does your brain hurt? Mine does.
I fail to see how that is better than Goalkeeper CIWS.
Weelll I can’t say “better” per say, but I can see a few differences that might make it appealing in certain scenarios.
1. On land (unlike sea where I see all the images of Goalkeeper being used), where bullets land might actually matter so trying to throw enough of a cloud up to take down a whole swarm might have some unintended consequences. Sure, I imagine they have to be set to avoid other ships but that’s still a simpler challenge than having to figure out all the firing trajectories that might need excluded if it’s used anywhere near civilian populations on land.
2. No specialty ammo to resupply. If it’s got a built in generator of some kind then you just need plain old diesel (or gasoline) to “reload” it, as long as there’s no quick wearing components somewhere in it.
Many moons ago i worked for a company that built the goalkeeper, a naval system to defend against incoming rockets. It had two radars, one rotating radar to find targets and another tracking radar to follow the selected target. It was rumored that this tracking radar ( STIR, https://www.radartutorial.eu/19.kartei/07.naval/karte068.en.html ) could also be used to shoot nearby pidgeons from the deck.
Well, I’ve got an empty shipping container and a large parabolic antenna. What could possibly go wrong?
“In recent years small drones have gone from being toys and photography tools to a deadly threat on the battlefield.”
Totally wrong. War drones predate toy drones by decades.
But this is Hackaday: stuffing text – without any fact checking – is more important than publishing accurate articles.
I read it the other way round: Small toy drones like DJI drones are equipped with darts, grenades and explosive charges for attacks on both sides of the war of assault we have in Europe right now.
So the sentence makes sense to me. Ofc (even small) drones predated the toy drones, but I think the author does literally mean: toy drones equipped with deadly means…
Not to mention that the toy multirotors are called drones not so much for their autonomy as their propellor drone sounds
So THOR can easily shoot down drone swarms but our government couldn’t take out one balloon?
In other news… there was a massive explosion at a Jiffy Pop plant that resulted in a huge surge of popcorn tearing open several buildings. No one was injured. Police are asking locals not to rush to the scene with butter and salt. The military when asked denied any connection between the incident and the testing of their THOR device.
You would have to be a Real Genius to do that to the guy who stole your idea ;^)
As you’ll remember, taking down the balloon was trivial. Picking the crash site not so much.
Drone swarm defeated. Meanwhile, the burrito’s center is still ice cold.
vaguely reminds me of the Dune 2 Sonic Tank
Range is likely to be all the way to the horizon and the bean focus would be controllable too. If civilians can bean WiFi up to 300 km you can imagine what the military gear can do when they don’t have regulatory limits on power output.
>Named the Tactical High-power Operational Responder, or THOR (presumably they picked the acronym first)
It’s called a bacronym.
They make microwave-homin missiles to hit RADAR installations, and now I’m wondering how small they can make those these days. Next chapter might be anti-anti drone weapons on anti-anti-drone drones AADD.
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