Comment by sbierwagen | Hacker News Reader

Comment by sbierwagen | Hacker News Reader

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https://news.ycombinator.com/item?id=27440924

>>The Block 1A and newer (pneumatic driven) CIWS mounts fire at a rate of 4,500 rounds per minute with a 1,550-round magazine.

>>Shells fired by the Phalanx cost around $30 each and the gun typically fires 100 or more when engaging a target.[14]

>So it's about three grand to zap one drone, and you get 15 shootdowns before a human needs to shovel more ammo into the turret. That would make it vulnerable to a saturation attack.

You could imagine firing fewer rounds per salvo, but that only slightly mitigates it. Against drone swarms you kinda want directed energy weapons, either microwave or laser. Which don't exist, currently.

Also note that Phalanx is radar based, leaving it open to the usual suite of radar jamming/ECW/antiradiation attacks.

You can tip the odds back in your favor by emplacing more Phalanx systems, but at ten million bucks each, that limits you to stuff like defending small-size/high-value targets like the White House, rather than numerous and sprawling US military bases.

> Against drone swarms you kinda want directed energy weapons, either microwave or laser. Which don't exist, currently.

These guys reckon they can detect, locate, and take down drones and drone swarms by jamming them with directed RF (not energy weapons as such): https://www.droneshield.com

These guys build "remotely operated weapons" that include 5.56mm up to 30mm cannons (as well as grenade launchers and missile launchers), and a "Counter Drone Defence System" that can drive them: https://www.eos-aus.com/defence/

I don't know it this works anything like as well on moving targets, but what you see at about 30 secs in this video looks like it'd take down most significanbtly-smaller-than-Predator drones pretty reliably at 900m out: https://vimeo.com/429825806 And I suspect 7.65 or 5.56 would probably work just as well as 50cal for that (though perhaps less accurately at long range?)

Not anything like as vicious as Phalanx, but if you're trying to protect against quadcopter or fixed wing drone swarms instead of cruise missiles, I'd bet they're remarkably more cost effective.

Actually proximity fuzed rounds should work the best, each taking outv many swarm memvers. Its not like these things could be armored rather than as light as possible.

Proximity fused rounds do have the significant downside that using them near built up areas will cause significant collateral damage. For example, if a drone swarm attacks an election rally somewhere in the US then you can't really detonate airburst shells above the crowd to take out the drones, since you would do more harm than good with that.

Hmm, a slightly Rube Goldberg type idea - what about firing proximity fuzed "airbag rounds" ? A Kevlar bag + car airbag style gas generator. If fuzed and timed just right it could potentially punch the drone from the sky, either breaking it or casing enough flight path distortion it migh not recover.

Or maybe release a bunch nylon filaments that will entangle any propellers and make the thing fall down ?

Would you? What if the drones are carrying grenades?

I mean, I can see how it’s less than ideal, but I don’t think it’s safe to assume you’d do more harm than good.

If you can say for certain beforehand that the drones are carrying grenades, then _maybe_. But if they are "just" carrying a sharpened stick to try and skewer whichever politician is holding the rally with, then killing a large amount of the audience will be really unpopular Also, not killing them but allowing the politician to be killed will be really unpopular too. Lasers on the other hand don't run out of ammo, cause much less collateral damage and are quite effective against lightweight drones.

(Of course by the time you have to guard political rallies so much that "grenade attacks by drone swarms" becomes a reasonable threat scenario, you may have to rethink things and probably just cancel the rally for now.)

Lasers still can cause potentially blinding unwanted reflections. Still likely a better option than supersonic shrapnel from standard proximity fuzed rounds though as collateral damage goes.

Yes lasers are not perfect either, for example the chances are often fairly high that a shot-down drone will fall onto something (or someone). Like I mentioned before, if drone swarm attacks are a part of the threat model then you might want to reconsider if you want to let civilians near the event at all.

Or just load up birdshot haha.

Birdshot at 100 shots per second ;-)

Second thought: is there something like a "constant airgun"? Where you just drop in pellets from a hopper into a high speed airstream?

https://m.youtube.com/watch?v=zyC-F_7QXtk

Like this?

> shells fired by the Phalanx cost around $30 each

That's pretty crazy to think of ... I guess the only justification for that is that the assets that are protected by such a system are worth more than that.

> You could imagine firing fewer rounds per salvo

If I learned anything from games, it's that you want AoE damage for swarming enemies ;-)

Phalanx was designed to protect battleships and aircraft carriers from cruise missiles.

Emptying 6 or 8 4500 round Phalanx turrets at the half dozen cruise missile locked onto your aircraft carrier seems like a pretty sensible way to spend a million bucks.

it costs $27,000 to fire this weapon... for 12 seconds.

Still less expensive than NAT gateway though /s

It should certainly be possible to develop and use a cheaper anti-drone system than a Phalanx, but that requires a static specification to develop against. The attacker's advantage seems to be that defenders doesn't have that yet.

I think for drones of this kind you can set up mini phalanxes. They don’t quite move at the speed that a missile moves, and the caliber necessary to destroy a drone is much lower than that necessary to disable a missile.

And [load them up with birdshot](https://news.ycombinator.com/item?id=28757668) ... or even salt. I guess most props won't handle any impact well.

and this is not even taking into account the difficulty to actually hit a target this small with a projectile weapon.

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