US Air Force shoots down drone swarm with THOR microwave weapon | Hacker News Reader

US Air Force shoots down drone swarm with THOR microwave weapon

thedefensepost.com

170 pointsMR4D246 comments

“non-kinetic, speed-of-light microwave pulses”

Presumably the version that uses kinetic faster-than-light microwave pulses is still classified.

Shhhh. Don’t want to be on THEIR naughty list.

It isn't like they are generating plasma conduits with the microwaves and then using a hyper velocity gas gun to propel a slug of plasma down the conduit!

Hammer's Slammers, anyone?

In the series of books they would use a laser to carve a hole in air and then inject a plasma made of super-heated copper into the collapsing channel. I always thought it was a pretty neat concept. That, along with their flying tanks. They used big fans to lift these M1 Abrams style battle tanks. I cannot imagine the power consumption for all of it.

Sounds similar to that "guide lightning using a laser" thing from a few months ago:

https://www.abc.net.au/news/2023-01-17/scientists-use-laser-...

actually the pulses went back in time and killed the systems inventor. So it no longer exists.

I recall reading about some microwave or laser weapon which was pulsed to in theory increase effectiveness. Part of the design was using kinetic effects and the sub light speed propagation of pressure waves through the material.

Basically rather than trying to vaporize armor you heat or blast chunks off in rapid succession which can do all sorts of things including creating strong magnetic fields. Which was then possibly more efficient in defeating armor etc.

I can’t find the exact source but this seems related: https://www.nre.navy.mil/organization/departments/aviation-f...

The kinetic slower-than-light microwave pulse is just a guy throwing microwave ovens at drones with a catapult

Add a targeting computer on the catapult and it might be pretty effective!

Used microwaves are almost certainly cheaper than any similar munitions used by the us mil.

But if someone microwaved fish in one it might be a violation of international law.

Know this is supposed to be a joke but why

Microwaving a trout actually works pretty well, but the joke is that it releases enough odor that just might be strong enough to be banned under The Hague Convention Against Chemical Weapons.

It’s definitely not a nice thing to do to the office microwave!

That's impossible, even for a computer.

So it basically does an omae wa mou on the enemy?

While I’m working mainly on drones/robotics, counter drones is also becoming a big talk with a lot of interest from investors, however, countring drones isn’t that easy, even with latest sensors (sound/visual/Lidar/radar sensors), there’s a lot of false positives when deployed in real scenarios, one trial we tried near an airport, the system we tested caught a lot of birds as drones, you tune it not to detect it, then drones goes undetected. Some systems tries to us AI to study the fly path and find some anomalies and trigger based on that, but so far I didn’t see personally an acurate system that can reliably detect and neutralize. Swarm on the other hand, might be easier given how easy to detect them.

Airport is probably a very different environment, though? I imagine that if you have a military installation, you don't mind blasting some birds with RF every now and then (and the birds probably don't mind either).

As a passenger on commercial aircraft, I don't mind reducing the bird population near an airport.

A bird is small and largely non-conducting. I'd guess it could plausibly survive a burst of microwave that could disable a drone, at any practical distance from the weapon.

Microwave tends to "cook" you.

Microwave covers a huge range 300 MHz to 300 GHz and they want something that will work in the rain or fog which means minimizing absorption by water as much as possible.

I think that if a drone is threatening civilian airline traffic you don't mind blasting some birds, either.

Unfortunately I do mind. Here’s where I live, there’s a bunch of endangered birds that live near the airport and don’t live literally anywhere else. Can’t really just go shooting them with death rays.

If any birds are in that situation near a military base or war zone I hope we got some if them in a zoo or dna as a backup for if we invent really good cloning since otherwise those birds are extinct

There's no war zone near me, so I guess the military doesn't need to shoot birds.

unfortunately, Korea have

The priorities at that point would probably be stopping any terrorist threat before protecting endangered birds.

There's no terrorist threat but there are birds, so we shouldn't just shoot birds for no reason.

Same here. I have zero terrorists in my backyard. I do have kids, rabbits, lots of birds, kites, etc. What's up with these idiots thinking about putting this microwave bird killer in my back yard where there are no threats against which to protect. Idiots.

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The best way to detect UAVs remains the EM they emit themselves, be it telemetry or electromotive hum.

The footprint for small drones is almost negligible, and flying at lower altitudes make it even harder to detect.

Shoot a bird laser [1] at it and if it doesn’t respond, it’s a drone.

[1] https://www.birdcontrolgroup.com/

For the motor hum, yes. Telemetry/Control however is very easily detectable by design alone. Especially for consumer drones and their known spectrum/patterns.

>Telemetry/Control however is very easily detectable by design alone.

Is it? as I said in another comment, I would love to know how you will detect a drone C2/Telem link flying over cellular, or LoRa?

Consumer drones have RC links, flying either at 2.4GHz or ~900Mhz, that can be easily detectable, but you can easily equip a consumer one with other communications capabilities

Silly question but is it possible that the army would not care about birds triggering false positives if the weapon can do the work fast enough?

Yes. You give away information about your position and capabilities if your defensive system triggers inadvertently.

How about trying your tech in Ukraine.

> Russian electronic warfare (EW) remains potent, with an approximate distribution of at least one major system covering each 10 km of front. These systems are heavily weighted towards the defeat of UAVs and tend not to try and deconflict their effects. Ukrainian UAV losses remain at approximately 10,000 per month.

How hard is it for a drone to detect your counter drone system and target it?

I guess if they managed to miniaturize it so that it was handheld somehow? Seems a bit performative but I guess lots of stuff did 20 years ago.

but drones are cheap, so make them sacrificial to find the counter-drone battery and then send in firing mission on the battery

That's what I mean by performative, yes.

If it were somehow miniaturized and handheld then it's easy to move.

I doubt that's physically possible, but I've been surprised before and am old enough to have been surprised before about how clever people are.

It looks like they are primarily thinking of this as protecting a non-mobile installation like a base vs troops on the move. So miniaturizing for hand-held might come, but the power supply for that would also have to shrink making it less useful. I see it mounting to a truck as part of the convoy moving troops during an advance to make it mobile

I would be extremely impressed with the engineering that would be required to somehow overcome the issue of focusing that wavelength at range. They don't mention the range in the article, so I'm suspicious.

It's extremely hard to imagine it having a range bigger than that which is effectively covered by other methods already. The laser makes way more sense to me, at least then the energy isn't spreading out super fast. But you never know, I absolutely did not believe optics would get sophisticated enough to manage realtime actual 3D displays (not VR, like https://voxon.co/technology/).

If they can do that with optics, I know I can't imagine what people with giant budgets can do with antennae.

Maybe a muon or electron or some type of particle beam weapon may be a better idea. Although maybe the wave vs particle spookiness may rear its head and a Faraday cage may stop one of those things too.

> there’s a lot of false positives when deployed in real scenarios, one trial we tried near an airport, the system we tested caught a lot of birds as drones

Those weren’t false positives.

https://birdsarentreal.com/

There's a lot of electronics on a little drone that all produces a lot of noise. Depending on the control schema it may be dumping a video feed or telemetry to the base station (typically over 2.4Ghz?). There's also an incidental EM footprint put out by the electronics on board. Brushless motors are extremely electronically noisy and shielding is expensive (by weight, aluminum foil works, but to be effective it needs to be wrapped around everything). I'd go hunting for ways to characterize that EM signature at a distance. Do you need to point a big collection dish at the target? Yes, very likely, but it should get you beyond the standard set of false-positive scenarios caused by Not Enough Information (TM).

Can we listen for motor noise broadcast by the brushless motors?

> Brushless motors are extremely electronically noisy and shielding is expensive

If we're comparing RF noise quantity, brushed motors generate a heckuva lot more RF because they're spark generators. Of course modern drones don't use brushed motors much.

Brushless motors can in principle have their RF noise reduced by careful modification of their controller waveforms.

But your point is well taken. Brushless motor RF is probably easy to identify by the presence of a few peaks on the spectrogram representing multiples of the rotation frequency. Brushed motors would look like that too except buried in a lot more white noise.

C2 (command and control) and Telem links can be communicated over different means, either cellular, satcom, or even LoRa, how you will differentiate the drone modem from thousands of UEs in the vicinity? what if the drone flying at a low alt, near power lines and other EM noise? one time I made a drone that detect interference sources for a gov agency to detect any violation of the spectrum, a giant LED can cause so much noise more than any brush-less motor, let alone a small drone ones. Maybe if you have a giant drone (plane size) and flying at a high alt in an empty area, maybe, anything else I would say it's impossible or very hard to reliably use EM as way for detection.

Does not matter. Total bird death. We need a system like that anyway for mass bird killing to actually contain avian influenza, otherwise it's just a game of waiting until it gets into humans.

Do you mind sharing what make (vendor) of radar being used? The “AI” in these types of systems is usually more likely classical ML than deep learning, in my experience. The problem is solvable, but it needs more training data and investment to solve to some acceptable performance level. There are a lot of companies trying to cash in on counter drone, and hype-speak like “AI” abounds.

A spy!8-(

Did they also trial it against a drone swarm that knew about THOR (which an assailant would) and had put the drones in "not even Faraday mesh" but just a fairly open wire sphere because microwaves are trivially neutralized with a "mesh" that has several inches of space between the wires?

(E.g. wired cages that are already commonly used by drone-operators in the ducting/smoke stack/container/etc inspection business to prevent their $50k industrial drones from crashing into walls/ceilings)

Because a test that doesn't test "what happens when the enemy knows the weaknesses" is not a test.

The drones would fly in a faraday cage? Really? Even if so, that's more cost and less weight they can carry. I am sure the US mil would also be concerned its own drones can be shot down like that.

A faraday cage protects against interference but does it shield against energy? Are they using microwaves to excite components in the drone or is it more like a MASER where microwave is used to deliver energy?

If this was light for example, I would equate what you are saying to coating the drones with a mirror, but if it is something like a LASER it would still damage the drone.

Conductive paints/coatings exist.

You've clearly never heard of building inspection drones. The drones fly in a sperical cage, which you can trivially run wires through, or over, to create a Faraday cage after programming the drones to fly whatever pattern you need them to. Hell, buy some copper tape, off you go.

Just because you didn't know about this thing, doesn't mean drone operators in military positions don't know about this either.

I did not know, I did not presume what military folks know either.

Military folks participate in drone competitions, and talk to R&D labs working with drones as well as civilian services that operate drones (mostly because the military itself also needs drones, and they need to stay on top of what's happening in the field). They know what's happening in this space, even if most other folks don't.

> You've clearly never heard of building inspection drones.

Maybe they haven't (also, you're being kind of aggressive here - why?) but I think most likely the people building these weapons have. Just because the article doesn't mention drones-in-Faraday-cages doesn't mean that the military are dummies who haven't thought about it / don't know anything about what kind of drones exist.

Eh, just responded in kind. The "Really?" to make it sound like I was talking out of my ass was as necessary as my "clearly".

Why do building inspection drones need a social cage?

> put the drones in "not even Faraday mesh" but just a fairly open wire sphere because microwaves are trivially neutralized with a "mesh" that has several inches of space between the wires?

My physics is getting a little rusty, but I wonder - are microwaves going to "flow around" this mesh, or "flow through" (following a path along the surface and not leaking inside, ofc.)? Because if it's the latter, then I'd guess that enough energy pumped into microwaves will melt the Faraday cage.

Very true, although the question is at what distance it would effect that, because a clustered explosive payload just needs to go off near the target and have the pressure wave do the rest. Going off "on" the target is ideal, but not strictly necessary to do the damage it needs to do.

So I'm thinking - on the one hand, the effectiveness of microwaves drops with r². On the other hand, this solution enables continuous tracking and delivery (whether the beam itself is continuous or pulsed), and it only uses electricity, which may have significant logistics benefits over any kind of physical projectile.

Definitely, but when it comes to counter-offensive, the same rules apply: you don't need to blow up each drone in a swarm. You just need to cause a big enough explosion near enough drones (just like how we don't shoot airplanes or ships by direct impact anymore, we "make thing go boom" close enough to a plane or ship to cause enough catastrophic damage to the flight surfaces/hull and if there's a direct impact, that's just a bonus)

It's 1/r², and the pulsed currents induced into the proposed wire mesh would likely produce some strong local EM effects -- possibly enough to overwhelm the rest of the drone electronics.

Sure, you could build a drone to resist this sort of attack, but SWAP would go way up, and range + mission effectiveness would go down.

I wonder if pulse-wave beamforming can amplify the microwaves to the point where it is < 1/r^2.

You are way way off on your faraday cage gap sizing.

In order to block EM fields with frequencies of 10 GHz and lower, the hole size of the Faraday cage should be smaller than 3 mm.

You want the hole to be less than 1/10th the wavelength of the frequency you’re trying to block

> Because a test that doesn't test "what happens when the enemy knows the weaknesses" is not a test.

Sure it is, if the opponent can't deploy effective counter-measures.

It doesn't matter if a protected drone is possible what matters is whether or not the opponent is capable of actually deploying protected drones. In a cat-and-mouse game all that is important is having an advantage for some period of time. It's not necessary to have the advantage persist indefinitely.

See: Russia's military being battered by very old technology every day in Ukraine, where in many cases counter-measures are well known but unavailable.

I'm fairly certain that countermeasures could be had for a few grams of increased drone weight that wouldn't otherwise change the drone form factor or flight characteristics.

This is left as an exercise to the reader.

That promo video has "suck it Iran" written all over it. Right down to the truck launches and drone shapes.

I do admit I wonder about single point of failure with this, so hopefully it's part of some layered strategy. Maybe with some flingy nets, those matrix-barrel guns with like 100 barrels in a grid, eagles trained to swoop down and pick apart the props, etc. etc.

> I wonder about single point of failure with this

Myself as well although I think this is already one of the last lines of defense. These drone swarms don't have a great range so the launchers need to get lucky to get close enough in the first place (I'd hope).

The new, terrible ‘bat bomb’!

> eagles trained to swoop down and pick apart the props

I assume the eagle dies or gets a horrific injury in this scenario?

Generally not: https://www.michigan.gov/egle/Newsroom/MI-Environment/2020/0...

They tried that, in The Netherlands, I think.

They stopped the initiative. Not sure why, but they didn't think it was effective.

Surprisingly they seem very capable of taking down drones uninjured. They have very strong legs, and with a flexible attack from below they can avoid the props.

Here's a video of some french trained eagles showing how easy it is.

https://m.youtube.com/watch?v=b8kZupqPbJs

I had a wedge tailed eagle take down one of my drones while filming. Drone ended up dropping to the ground damaged while the eagle wasn’t too bothered. It just perched nearby and watched me picking up pieces, not preening or appearing at all injured.

In Neal Stephenson's Termination Shock, a character has trained raptors to take down drones and he crafted 3D printed sleeves to protect their claws from damage during attacks: https://www.nealstephenson.com/termination-shock.html

Training an eagle is expensive and time consuming compared with the swarm. A few explodey drones and an expensive eagle fleet is toast. We’re talking months to years to gain a single eagle’s trust

[edit] Disclaimer: I volunteer at a raptor conservancy. Please don’t propagate the belief that eagles or other birds of prey are an effective counter-drone strategy at scale

I’ve always been curious about eagles as drone deterrents: wouldn’t the birds’ feet be potentially damaged by the propellers on the drone? Admittedly I don’t know what kind of propellers a fancy airport-menacing drone or shahed drone is using, maybe they’re just some kind of plastic.

A shahed drone is, compared with an eagle, a small light aircraft with a piston-engine pusher prop and an 8 foot wingspan. An eagle couldn’t take one down any more than it could a Cessna, essentially

Ah, I didn't know that. So the shaheds are the larger sort of military drones the US and other countries use, more along the lines of reapers and predators than something like a retail drone you or I could buy on Amazon for instance and control with our phones. I'd heard some of them were being used in Ukraine as kamikaze explosives and figured they must be cheap little things being sent into targets. Thanks for the info.

Glad to be of help!

>> kamikaze explosives

(A couple of years ago these were called loitering munitions, with the meaning of a smallish UAV that could, well, loiter until a target presented itself. Personally I never liked the term 'kamikaze' because destroying yourself is true of shells, cruise missiles, etc etc.)

given the number of actual incidents involving shooting down drones in recent months, it might have been nice to include right in the title that this was a demonstration, and not an actual deployment against an enemy.

FWIW, it was a practical test, so while it does not presage war for the US, it does prove that this is a real weapon outside of computer simulations.

Yeah, for sure. But we aren’t under attack, and headlines should tend to avoid any possible confusion about that

Lots of words but not much detail. What I'm interstates to know:

- The effective range of the system, if the range is only 100m or so then you might need a lot of these to protect a larger strategic area.

- How it neutralises the drones, does it overheat certain components or just inject sufficient noise into the system that the flight controller stops working or just disrupt any command signals.

My guess is it just overwhelmems the control. Solving auto-homing sounds like a hard problem and it's more feasible to just have the drone land on the loss of control.

> THOR engaged the targets and knocked them out of the sky using its non-kinetic, speed-of-light microwave pulses.

Maybe that's military jargon but in Physics photons definitely carry and deliver kinetic energy.

A kinetic weapon is one that damages the target by smashing into it. Blunt projectiles like rocks, arrows, bullets, etc.

This is a non-kinetic weapon, because it does not damage the target through kinetic force.

> This is a non-kinetic weapon, because it does not damage the target through kinetic force.

It is literally the kinetic energy of the photons and nothing else that is disabling the drones. The photon kinetic energy is transferred to electrons that either overheat components or destroy control electronics with excessive voltage (the article did not specify which).

Unnecessary pedantry. You know what the title meant.

Intended audience: not physicists.

It's the kinetic energy of a HEAT round that damages a tank too, but that's not classified as a KEW either, since a KEW is where the sole damage done is by the energy of a projectile (and a HEAT round it's the chemical energy in the round that produces most of the damage, after being converted to thermal and kinetic energy).

I will propose that (generally speaking) a projectile has mass, which would exclude photons from the definition.

so classification of non-kinetic weapon versus "non-kinectic light wave pulses"

seems like grammatical confusion to me...

microWaves ≠ photons. It just has to mess with the target’s waves with precision chaos.

Microwaves are literally photons. They're waves because of https://en.wikipedia.org/wiki/Wave%E2%80%93particle_duality#...

In the context of microwave systems, the most relevant information is coming from the waveform function, not the substrate. The densely distributed particles are making small movements in response to its neighboring particle’s ‘tensors’. I think a lot of people think of the laser concept of photons shooting through space, but with masers the waveform and it’s amplification are what make it meaningful.

Well… aren’t microwaves electromagnetic waves and as such photons?!

Yes, I do think the military usage is different than the physicist's usage. I don't think (or at least cannot find) a consistent, hard-and-fast definition, but it seems like they are using kinetic in this sense to mean something that goes boom, and looks cool, and is hard to deny when shown on television. One thing I'm fairly sure about is that they aren't thinking about physics when they use that phrase!

https://en.wikipedia.org/wiki/Kinetic_military_action

Military usage of the words ‘force’, ‘momentum’, and ‘charge’ also don’t follow their classical physics definitions.

Likewise military specialists look confused when mathematicians ask them whether ‘military operations’ are commutative.

I remember describing something as hyperbolic (meaning ridiculously overstated) to a guy with a degree in some sort of fluid mechanics related thing, and he was like "I'm impressed you know that word, but that's a very specific term that doesn't mean what you think it means...", because it is a term he only knew from work. I had to show him a dictionary to prove that sometimes the same word can have different meanings. I'm sure this is an example of that.

It’s energy, but is it kinetic energy? The photon’s massless, but it has momentum… so it can transfer kinetic energy, but does it do so kinetically?

More to the point, ‘kinetic energy’ is ‘movement energy’ - energy you possess by virtue of the fact you are moving.

Show me a stationary photon and we can talk about its ‘kinetic’ energy vs. some other kind of energy.

I don't understand that, given that momentum is mass times velocity. Can you explain?

For a photon, momentum is (edit) the inverse of its wavelength, times the Planck constant.

I appreciate that this is not really an ‘explanation’.

Momentum is proportional to frequency. Inversely proportional to wavelength.

Thanks - corrected

Non-relativistic momentum is (simplified to) mass times velocity.

Photons have zero mass, but still have momentum, p=h/λ.

Mass == energy.

> photons definitely carry and deliver kinetic energy

Technically correct, practically irrelevant.

Full direct sunlight exerts 1 ounce per 20 aces.

---

Kinetic weapons are bullets, bombs, etc.

As contrasted with chemical weapons, or electromagnetic weapons.

>>[the] weapon proved effective in neutralizing multiple targets even though it had never before been tested against the types of drones used in the trial.

Presumably THOR was tested against American and/or foreign-made retail drones, and not foreign military-grade drones. Hardened electronics aren't a new concept.

Still a good thing that they can stop massively asymmetric attacks (huge number of cheap drones with cheap explosives)

I presume that the Defense Department's experts are well aware of these things. The article is sparse in details. Maybe they did test this new capability on "military-grade" drones, whatever "military-grade" means. Military technology isn't always superior to civilian, commercial technology, as anyone with even a passive familiarity with government acquisitions could attest. Both Ukraine and Russia have resorted to modified commercial drones in the Ukraine war. A North Korean drone was once recovered that was nothing more than a piece of crap with a cheap camera mounted[1]. Really, the only serious and adversarial competitor in the drone space is China.

[1] https://www.cbsnews.com/news/suspected-north-korean-drones-l...

> While the capture of the two surveillance drones appears to offer a rare glimpse into the North's technology, analysts stress they do not necessarily represent the best unmanned aerial vehicles the North can field.

Always be skeptical of aggressive mimicry. A "piece of crap with a cheap camera" is cheap and disposable-- and misleads those quick to jump to conclusions. It's what you deliberately throw over the fence when you want adversaries to think you're underequipped.

They have nukes for fuck's sake. They can afford real drones.

May be true, but a lot of the stuff flying over Ukraine is retail. Future conflicts may be similar.

DJIs seem to be popular

https://gagadget.com/en/153538-ukrainian-intelligence-servic...

This is so snarky I cant tell if its genuine or mocking.

Hardening against really high energy pulses adds weight, and quite a lot of it. And flying things don't like weight.

It'll be arms race, as always.

> It'll be arms race, as always.

Example: You send 10-15 cheap drones against a side that employs THOR. When the drones get close to the target THOR will activate itself and bring down those 10-15 cheap drones, and thus revealing its position. You then target THOR directly either with artillery or with a slightly more expensive missile. Once THOR is out you can then send 100 to 200 cheap drones. Rinse and repeat.

Yep. But the picture shows it mounted on a trailer, so its position doesn't have to be static.

In theory, yes, in practice, it's more complicated.

Supposedly a similar thing happened with the recent attack on the Patriot system in Kiev, i.e. the Russians first sent some cheep Geran drones, the Ukrainians shot them down activating the radars around the Patriot system (or part of the Patriot system? not that clear), then the Russians sent some anti-radar missiles that took those Ukrainian radars out and in the third and last stage they sent some more advanced missiles that directly targeted and damaged the Patriot (which was by then without radar protection). Almost all images of radar systems that I saw from this war in Ukraine involved mobile units, both on the Ukrainians' and on the Russians' side.

That's not how it works, the Patriot is a completely self-contained distributed system with a lot of redundancy. It has its own networked radars that can track both missile and aircraft threats. In the instance you are referring to, the Russians tried to flood the zone with a mixture of flight profiles simultaneously (ballistic, cruise, and drone) to overwhelm and complicate the defense. An air defense missile optimized for ballistic missiles won't be great for cruise missiles and vice versa. Patriot batteries contain different missiles optimized for aircraft/cruise missiles (PAC-2) and ballistic missiles (PAC-3).

While there are human operators, the Patriot has a fully autonomous mode that is turned on for large-scale attacks like most integrated defense systems produced by the US. When that mode is enabled humans are no longer in the loop; the networked computers engage all of the targets simultaneously, selecting the optimal weapon assignment and timing for each target. That was clearly used here. If the Patriot didn't have radar it wouldn't work and it clearly worked.

No Patriot system was damaged by Russian attacks, there is no evidence that anything got through. The only reported damage was an auxiliary system component getting hit by a large piece of falling debris, which was promptly repaired.

> which was promptly repaired

...using Duck tape, apparently.

> No Patriot system was damaged by Russian attacks

As per the US media [1]:

> The damage to a Patriot air defense system following a Russian missile attack near Kyiv on Tuesday morning is minimal, three US officials tell CNN, with one official describing it as “minor” damage.

The say the damage was "minimal", but it's there. (and the "minimal" part only showed up later, after the CNN reporter who had first reported it all got accused of being a Russian shill because of it)

[1] https://edition.cnn.com/2023/05/16/politics/patriot-missile-...

> thus revealing its position

Takes a pretty serious piece of tech to do that part though

Yea, would it make a lot of noise, you wouldn't really see it right? Would the energy be detectable by some sort of equipment that you could visualize on the screen?

Triangulation?

Your artillery fires on my THOR but its projectiles are taken out by my C-RAM. Your artillery’s position is noted by my ISR overhead. Your artillery is destroyed by my longer-range artillery. Your 200 cheap drones attempt to attack but are taken out by my still-extant THOR. I now hit your launching point with my artillery again.

All of you do realize war is never as clean and predictable as you are all making it out to be right?

You "just" get THOR to fire and take them out?

You "just" take out inbound artillery?

I haven't paid attention to them since the First Gulf War, but the abilities and competence of the 101st Chairbourne continue to be renoun and without equal.

Yes, it will be all a matter of execution. And as this is supposed to be used either against the Russians or against the Chinese it will all depend on how the Americans' execution will compare to that of the Russians and/or of the Chinese.

Can't speak about the Chinese, but because of this war in Ukraine the Russians definitely have a very big head-start when it comes to the execution of anything artillery-related, as in I don't think the Americans have had to fight a real counter-artillery fire since at least the Battle of Hue. Maybe the Ukrainians (also pretty experienced by now) will teach them, if they (meaning the Americans) will be open to learn.

I think the parent just tried to demonstrate what the "arm race" really mean. I.e. they just countered your hypothetical with another one.

As for the the Russians, they clearly shown that spending tons of munitions to make holes in the open fields is not really efficient. [1] Ukrainians on the other hand are pretty successful in counter-battery fire using US (sic!) systems. See HIMARS, for instance.

[1] https://s2.reutersmedia.net/resources/r/?m=02&d=20220617&t=2...

> See HIMARS, for instance.

HIMARS has started to successfully being jammed by the Russians lately [1]:

> Russia has been thwarting US-made mobile rocket systems in Ukraine more frequently in recent months, using electronic jammers to throw off its GPS guided targeting system to cause rockets to miss their targets, multiple people briefed on the matter told CNN.

which probably should have been deserving of its own HN submission.

[1] https://edition.cnn.com/2023/05/05/politics/russia-jamming-h...

I would assume any such drones would be larger/heavier and in fewer relative numbers. As such, able to be dealt with by conventional means (surface to air missile defense).

> Presumably THOR was tested against American and/or foreign-made retail drones, and not foreign military-grade drones. Hardened electronics aren't a new concept.

So your assumption is that the airforce can’t source a military grade drone to test with?

Do they decide on an acronym first then work backwards to try and come up with what each letter stands for or is it just a coincidence that they landed on THOR? :)

It's called a backronym :)

As they say, "Someone really wanted our initials to spell out 'SHIELD'."

Chatgpt makes this fun and rewarding. How about: Mobile Integrated Countermeasure Radiating Overwhelming Waves Against Virtual Enemies (MICROWAVE)

Both way, I did some projects with military and they care much about these acronyms for some reason.

I imagine when you’re dealing with so many weapons systems it’s helpful to have memorable names. Beats the heck out of X1, X2, X3, X4, X5, X6 (not to pick on BMW, but to pick on BMW).

(Update: not to mention the need to appeal to Congress to keep funding these systems.)

Yep, it’s mainly for catchy names for funding.

If you want to pick on a company for strange naming, Sony is a great choice. WH-1000XM3, WF-1000XM3, Xperia 1 III, etc.

The last time they didn't do this, they ended up carrying MANPADS into battle.

I'd like to know more, like the power of the beam, and what it does to the drones. I'm not wow'ed to learn that an electronic circuit can be influenced by microwaves, nor that a HF radio beam can be jammed. I note the article didn't claim this thing can be used to disable an autonomous cruise missile using inertial/map-based guidance, and having no radio receiver.

Let’s also not forget LEONIDAS, which is a bit more mobile but smaller.

https://www.thedefensepost.com/2023/01/24/epirus-counter-dro...

I wonder if these devices could ever become powerful enough to be mounted on missiles and thrown at helicopters or planes and have them drop out of the sky - or mounting them on Growlers! Could be interesting as an alternative to explosives

Why call it THOR when it uses microwaves rather than bolts of electricity?

More expensive but I think small, fast drone interceptors would be better. Show them the target and then let the machine guide it there, squirt out some 5 cent netting and the target drone is toast if they use a propellor, if they use some sort of jet then hmm. Just have like 500g of explosive in the interceptor I guess.

Serious question, what if instead of pointing it to drones it was pointed to organic flesh? Wouldn't that microwave burst the water contained in someone's body?

that already is a weapon. as an example, they believe a low power version is what was used in havana.

Came to say this. It’s not a big mystery like the news keeps saying it is. How can one defend against this?

Tinfoil hat lining

Please make a tinfoil hat and cook it in your microwave and let us know how it goes.

The latest I heard about Havana is they believe that to not be the case any more. There are however crowd control versions for anti-riot purposes. They induce a burning feeling on the skin without permanent damage, supposedly.

I wonder who is doing the studies to prove no long term harm.

How would non-ionizing radiation that doesn't cause an acute injury result in long term harm? I would assume that you would need to propose a mechanism for it to happen, rather than try and prove a negative.

heat induced denaturing of proteins?

It is lower frequency than visible light, so, of course burning things is harmful but we’re not talking about ionizing radiation.

well if is actually heating the skin it could denature proteins? that can happen at a little 105 degree F. your body operates in the mid 90s naturally if its hot out it wouldn't take much added energy to push you over the limit.

EDIT

a quick wikipedai search says it can heat the skin to 111 degree F so yeah it could easily do damage.

Water has a pretty high heat capacity. Takes a lot more energy to kill a person this way than a drone swarm. For instance, assuming it’s about 20,000Watts effectively focused on one person, it’d take about an entire minute before you manage to increase body temperature by 3 degrees. Versus like a second to knock a drone out of the sky.

The question is, how much can you focus it? It would be enough to boil one vessel in the brain, to kill someone.

Not at all easily. Blood pumps quickly through the brain and back through the torso, quickly distributing heat. And probably the first thing a target would do when feeling heat would be to protect their head.

Bullets are more effective against flesh.

contrary to popular belief microwaves don't cook from the inside out. if you are getting a vessel in the brain to boil you have just fried their face like a egg

It's hard to know exactly how much energy this is pumping out and how focused the beam is, but suffice to say anyone in the way might start to boil.

There is a non-lethal version of this: https://en.wikipedia.org/wiki/Active_Denial_System

Yeah that's why the microwave spectrum is unlicensed. It's not supposed to be used and blasted on humans.

Defense engineers have more fun!

I don't know, I was offered to design and implement military cockpits UI and tracking systems for the biggest weapon exporter in Italy for a very good salary, a 60% raise of what I earned at the time and I was like "no thanks, I want to go sleep without thinking I'm helping writing software to kill people".

Since then I have a very clear clause in my contracts that I don't work in projects involving law enforcement, military and some other business.

Interesting point, I too have a similar moral, but I don’t mind to do something for defense, no?

Much like how one mans terrorist is another's freedom fighter.

One mans defense is another mans offense.

Surely this microwave can be moved to the frontlines and as the frontline moves forward.

You got a point, but going by that logic, as bladesmith, I should never make any knife because there’s always the possibility to be used the wrong way?

Knife have dual purposes, military weapons have only one.

It seems hard to guess based on the technology if something will be defensive or aggressive. I mean, silly example, but if you invent a suit of armor somebody will say “nice, now I can use my sword two handed, no need for a shield!”

Maybe nukes.

Exactly, I mean, if something is clearly will be used to kill or that’s the intention for, I can see the point, but what if it isn’t clear, what if your tool is used indirectly, say React framework which you are a big contributor to, is used to build a UI for X that you don’t agree with morally.. what’s the line here I’m curious?

Neither Italy nor any of it's allies has fought a defensive war in the last 80 years.

It's about weapon exports first and interfering around the globe.

I have a huge moral problem with it, calling it "defense" is hiding it's a business to kill people.

Sometimes it maybe better to bring the change from inside...

Like... if someone wants to build a kamikazi drone interceptor:

You convincing them to build a drone to just shoot a net to stop them vs. Other people trying to build systems that explode automatically...

You convincing them the decision to blow something up must be made by a human vs. Other people building systems that use computer vision to automatically "eliminate threats"...

Not to mention law enforcement, military etc.. are still humans risking their lives for their jobs... But yeah these things can be an minefield to think about... and is easier to find fulfilling work elsewhere...

Very neat. Wonder if drones could fly lower and swarm around it in an almost full circle. There could be anti-THOR suicide drones attacking first before the rest fly in. Then, would any shielding work or even some kind of a microwave energy reflector, like an inverted cone, to concentrate the energy back at the THOR system to use its energy against itself.

They say it's a wide beam. Is that a misinterpretation of the spectrum used or did they mean physically a wide beam, as opposed to a thin maser? That would be extremely inefficient compared to a pinpoint accurate defense, wouldn't it? I assume military drones are difficult to spot, so maybe they need a shotgun pellet approach.

Judging from the size of the dish, I assume it's a physically wide beam. That also means you don't have to aim as well, and you can - like they demonstrated in the video - point and sweep to take out a large swath at once without having to acquire each target individually.

I wonder how effective this is against a microwave resistant design. microwaves are incredibly easy to deflect, 1mm sheet steel at the right angles would be interesting to see. 1M USD start up drone company inquire here.

If you can fully shield the electronics with steel then you're probably good to go. The problem is any small gap in the shielding (such as for venting heat from the rotor motors).

Even aluminum foil can do wonders here.

tin foil hat drones incoming

The drones are going to be vulnerable because they need to have some kind of antenna to communicate externally, that presumably would be pretty broadband. It would be interesting to think about how one could harden them but still allow communication ... I think it's probably possible. Something like an nmr receiver that has diodes that short it out for high power input... I have no idea if that translates practically.

something like a small hole or slit in the deflecting body would allow different wavelengths through. The microwave region extends from 1,000 to 300,000 MHz (or 30 cm to 1 mm wavelength).

Or you could use some kind of fiber optic system, worst case.

Birds can navigate in large groups just based on several birds around them. If you had a swarm that was semi-autonomous after being launched, it could avoid comms altogether.

Interesting. I wonder if there is a design that could be fully autonomous, requiring no outside connectivity.

They're called cruise missiles and have existed for decades. Putting the same avionics in a drone is just building a smaller slower cruise missile.

Also dramatically cheaper, and well within hobbiest abilities.

> because they need to have some kind of antenna to communicate externally

I mean, that's true until it isn't. Autonomous drones (otherwise known as weird looking missiles?) being used to attack a base with a fancy microwave air-defence system isn't really science fiction anymore.

I suppose cameras might be hard to shield too?

It would probably also need GPS. I think it should be possible to harden a camera. Light can go e.g. though an arbitrarily small honeycomb mesh, while microwave cant. But it might be limiting in terms of what a ln autonomous drone would need to see. Lidar might be harder

GPS is jammable, I'd assume that the base with the fancy microwave anti-air system is capable of denying it and you'd want to be capable without it anyways.

Guidance via camera has been a thing for a long time: https://en.wikipedia.org/wiki/TERCOM#DSMAC,_Digital_Scene_Ma... I don't know if it's available open source (or commercially), but I don't imagine it would take me (or any other reasonably skilled programmer) long to develop it these days. Satellite imagery is freely available from google maps if you have nothing better.

Near(ish) peer adversaries (the kind that can afford drone swarms) are definitely capable of the guidance part.

Drones can fly safely with gnss denied environments, a system we tested it was in a mine with a very narrow areas, and at a relatively high speed too, being open in the sky would be easier.

How much do the direction/location of the antenna and incoming pulse matter?

The antenna could point up and communicate with satellites. Meanwhile the pulse will be coming from underneath. Maybe it could be diffused off to the side?

A high power microwave beam will pass right through plastics and composites. Unless you add a lot of shielding, that microwave pulse can and will induct a charge in wires and electrical components. Shielding is heavy and makes a drone easier to detect.

I build drones that fly over 5G, the link os also encrypted, and use the same medium that other UEs (cellphones) use in the area, it is hard to impossible to detect even with DPI, or at least by the time you detect it, the drone would be far gone. The only vulnerable point though is the GNSS, it’s weak, prune to interference and jamming, however, there are fail safe mechanisms that if that happens then it returns or land.

Aren't we talking about physically damaging the drones with high power microwaves?

OP mentioned using a steel sheet, and how vulnerable the signal can be, while it might work for RC ones, if you use a cellular network, it won’t be much of an impact. Now of you can detect and destroy the drone on time, then yeah that works, but you will have to solve the challenge of isolating the cellular drone first from all the UEs in the area.

If you could build a drone perfectly shielded with sheet steel it would be the size of a Cessna and have the radar cross section of a B-52. The perfectly shielded drone would no longer be fit for purpose. It couldn't sneakily fly over enemy lines to spy or drop bombs or whatever. A steel sheet covered drones would just get blasted by traditional AAA.

According to the article, this anti drone system works by targeting the electronics inside the drone with microwave pulses.

Dumb question: why couldn't the electronics be shielded like the door of your kitchen microwave?

anti-drone 'rifles' are used a lot in Ukrainian war by both sides. As I understand they mostly target GPS receivers and force 'disoriented' drone to land. Also there are attacks on control frequencies. Which are countered by frequency changes or hopping, obviously. Attack on drones electronics itself requires significant power. So that thing likely to have short range. AI powered drones, which don't need constant control and GPS, will be much harder to take down. They can be made today for about $1k, more for bigger ones.

Does it work in rainy days?

One has to wonder what incentive there is in publicising something like this. Indicating capabilities to potential adversaries seems to have utility in limited circumstances.

First of all: https://en.wikipedia.org/wiki/Show_of_force

Also capabilities have to be made public to show what tax dollars are being spent on.

Understating capabilities could have utility, no?

Maybe not, since the Star Wars program taught us that propaganda of capability is a good enough deterrent.

An ounce of prevention is worth a pound of cure.

It changes the whole game. We were almost defenseless from swarms of flying grenades before. Now, the military can handle that threat.

Most military missions are posturing, there many incentives.

Same reason for knowing the U.S. defense budgets, number of aircraft carriers, fighter jets, etc.

What's better than winning a war? Not having to fight one.

And also accountability to the citizens who are financing all this. A 773$B black hole in the budget would be undemocratic and rife for embezzlement.

The DOD is unable to account for 61% of its 3.5 trillion in assets.

https://oversight.house.gov/release/comer-sessions-open-prob....

>The DOD is unable to account for 61% of its 3.5 trillion in assets.

I bet most of the circumstances behind this stat are mundane. I used to be in military SAR and we had a mule[0] randomly go missing. We were mystified because it's not like a work-issued Blackberry you could forget at a Subway or something. It's hard to lose track of a 20-ton piece of GSE, or at least you'd think so. It later turned up in Kandahar at the coalition base.

These things happen; it's not malicious so much as the fact that mission success sometimes mean you take the wrong tow mule and "oh well".

[0]https://www.google.com/search?q=sellick+aircraft+tug

Reassuring

It's the nature of the beast, in the same way that sometimes developers need access to prod.

I think they've been working on that. The size of our military and the amount of logistics that occurs requires a tremendous amount of supply chain infrastructure that is not all wired up in to some centralized system.

You can imagine the complexity of auditing the work of tens of thousands of different individuals annually with 100% coverage in a system distributed all over the world that has just tons and tons of constant hard real world material needs day after day, year after year.

My understanding of the situation is that these early year audits were never expected to be a full audit of the entire DoD but the results of the path towards a more auditable system and that we'll see that number of unaccounted for assets continue to shrink over time.

It's only in the last decade or so a system that'd be auditable would be possible without it divesting huge amounts of manual resources at the accounting department as far as I can tell.

We're letting the aliens know the next time they try to invade our airspace disguised as Chinese weather balloons, we'll be ready for them. It'll be like the Battle of Los Angeles for real this time.

Seems to have pretty clear dissuasive capability.

Hard to say what's already known to be known by foreign intelligence. Doesn't hurt to publicize it if you already know that major potential adversaries know about it.

Also hard to say exactly how cutting-edge anything we get to see is.

If a relatively small research project is going to mean adversaries have to spend twice as much on drones which have heavy metal mesh shielding, that’s pretty great return on investment even if the capability is totally negated by that countermeasure.

Also, nothing was said about the maximum design power of this device. For all we know, they could ramp it up to 10x the power with a different power unit.

I think it was Truman who said “Speak softly but carry a big stick”. They have to see the stick for it to have any diplomatic effect.

Then there was Reagan who collapsed the Soviet Union with a mostly bullshit space defense initiative called “Strategic Defense Initiaitive”, aka Star Wars and SDI. That proved if the enemy believes the stick exists you don’t need to actually have the stick.

> I think it was Truman who said “Speak softly but carry a big stick”.

Theodore Roosevelt, actually.

Reagan (or , at least his advisors) was essentially following Moore’s Law in the SDI effort. He knew that computers were getting faster at an increasing rate and the Soviets couldn’t catch up.

Same thing happened in the space race in the 1960’s where the Russians had to build huge rockets because they didn’t have the miniaturization capabilities of the US.

Over the last few years there was a lot of hay being made about how drone swarms have obsoleted $military_technology_du_jour and how there's no real way to defend against "drone zerg", etc.

The USAF is probably publicizing this for two reasons:

1. To reassure domestic audiences that the USAF can counter these things to some extent and is working on it, and also probably to demonstrate return on investment for Congressional oversight reasons

2. As a form of soft deterrence; a reminder to unfriendly powers that "hey, we have this technology, imagine what else we have that we're not telling you about"

I remember the first time I learned about drone swarms was this YouTube video called Slaughterbots: https://m.youtube.com/watch?v=9CO6M2HsoIA

Of course at this point, my country had been using drones to kill people since I was a small child, which I think is ironic.

In the Slaughterbots scenario, each specific drone has sensors and AI good enough it can pilot itself and doesn’t need an external connection that can be detected or disrupted and is good enough to target individual people with facial recognition. I believe (this is not an area of expertise for me) that the drones depicted in that video are still far more advanced than what currently exists currently (but I think it could probably get there within the next 10-20 years), whereas the video linked shows a more realistic drone swarm attack where it’s targeting infrastructure and the blast radius is larger than being able to target an individual's head, but still smaller than traditional UAVs.

It’s an upsetting watch, but the part of me that enjoys speculative science fiction (I love evaluating how realistic the apocalypse is in zombie movies) always found the attempted countermeasures employed to be silly and unrealistic. Covering windows and leaving only tiny circles so no drone can get through etc…

But at the same time, the video struck a chord because as soon as I saw it, I knew some form of this was coming and likely within the next decade. But mitigations and countermeasures are being developed in tandem. I think that's the major thing the Slaughterbots video got wrong.

And there's many different potential countermeasures, they don't all have to be 100% effective, but together they form a kind of "net" that will make these attacks a lot harder to pull off.

For example, they now have a portable machine that can disrupt a drone swarm's sensors, which will at the very least require additional shielding (and increase cost per unit) which removes some of the benefits. It's possible the technology will prove even more fruitful after additional development and make drone swarms mostly untenable for warfare except in rare situations.

This is a very direct countermeasure, but I could also imagine other indirect measures like regulating consumer drone manufacturers and forcing them to add/remove features that make it more difficult to turn them into a weapon. The same way printers can't just print currency and GPS won't work if it's moving too fast.

Ultimately, for war it just makes it another type of weapon/tactic and there's already infrastructure for controlling how those things move between countries and intelligence groups that work to keep them away from terrorists etc...

Which leaves the possibility of a sole actor or small group without state backing turning consumer drones into these swarms. Which could happen, it could be a new vector of terrorist attack. But they'd still have to source explosives which is already monitored, etc... In the Slaughterbots video, these swarm attacks are extremely efficient and effective, killing 5000+ people at a time. I think a similar attempt from a homegrown terror cell would not be more effective than a mass shooting or traditional bombing in terms of casualties (< 50.) I think for it to become more effective, it would have to be done many times and iterated on by the same group, building up institutional knowledge. It's just too complex.

Like the idea of a "dirty bomb", I think it’s one of those things that is theoretically extremely dangerous but due to a mix of factors is unlikely to result in a situation like the one depicted in that video. A matrix of countermeasures will just make the juice not worth the squeeze.

I think about it like guns. There is a lot of gun violence in the United States, but it stems more from ideological gridlock than the government not being able to stop it if they had the will to.

The one thing that does worry me is the possibility of targeting individuals. So if you have a tiny drone that can explode and isn’t part of a larger swarm, then you could potentially murder someone in a way that is very hard to investigate. Much harder than a homicide involving a gun where someone had to pull the trigger. It could be the next evolution of SWATing someone.

Anyone have a formula for E(x,t) and H(x,t) for the actual wave?

Fwiw, large-scale jammer systems using radio frequencies are already deployed and quite effective in Ukraine. Curious what the advantage is here.

Perhaps effective against completely autonomous vehicles?

There are three ways I know to bring down a drone with electronic warfare:

- jam the operator's signal (RF)

- jam or spoof GPS/GLONASS (RF)

- fry the electronics

There are degrees of autonomy. Some autonomous vehicles do not rely on their operators, but continue to rely on GPS et al. Fuller autonomy requires an internal navigation system based on local data of the terrain to be navigated. In that case, the only thing left is to damage the on-board electronics. Google tells me this is what microwaves do...

https://www.sciencefocus.com/future-technology/drone-killer-...

Gonna be pretty gnarly when these get introduced into a theater of war and some desperate person points them at human flesh. :-|

Anyone know what this would do to a more traditional airborne threat (e.g. cruise missile or fighter)?

Now we need steam-powered drones?

It looks like this system might not have 360 degree coverage. Is that a weakness?

there is an opportunity to test this right now in real world battles and save a lot of lives. Just saying…

This should be useful in Florida!

Thor is he-yah!

aka Point Break

This thing is easily defeated with a small amount of software and tactics.

> THOR engaged the targets and knocked them out of the sky using its non-kinetic, speed-of-light microwave pulses.

Microwaves dont travel at the speed of light. Did they mean line of sight?

Edit - well guess I was wrong!

Why wouldn't they? They are just EM waves. "Light" is used colloquially for the visible spectrum but microwaves could be considered light waves

Microwaves do travel at the speed of light, all electromagnetic radiation does.

> Microwaves dont travel at the speed of light

Yes, they do, microwaves are just a wavelength of light.

You might have been colloquially correct. Microwaves travel at the speed of light, but my microwave that heats up a Hot Pocket can't. :-)

They’ll work in a pinch against a drone idling below your kitchen window.

You are actually correct. The speed of light you always hear about is the speed of EM radiation in a perfect vacuum. In a medium such as the atmosphere, the pulse doesn't travel as fast. The slowdown depends on the refractive index, which itself depends on the frequency of the wave -- longer wavelengths have lower indices. This means that microwaves will move the tiniest bit faster than light through the atmosphere.

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