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Comment by jonnycowboy | Hacker News Reader

The technology does not destroy the attacker but the projectile.

Also I assume objects travelling below a certain speed or heat threshold are not "processed" so most children or children-thrown objects would not be targeted.

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...so next step would be strapping anti-tank mine to heavy duty quadcopter?

Another possibility would be adding stealthy nose-cones to RPGs. Then you have to increase radar power of the defending system. ...which would help enemy artillery to target the tanks.

I'm not saying this system is nullified. Just that there will be ways to bypass it.

I strongly believe that the next step in asymmetric warfare will be the underdogs using swarms of drones where most are cheap, harmless "toys" to turn it into a numbers game to figure out which 1%-10% are full of explosives. As the cost of small drones drop, you'll potentially be able to drive up the cost of counter-measures dramatically with lots of dummies.

I'm not sure decoys are worth it really. Conventional explosive are cheap. Very cheap. You might as well stuff them into every "thing" you deploy.

It's different with ICBM's.

But yes, I think you have a point in that with COTS robot technology, it should be very cheap to produce swarms of simple missiles. If the adversary answers with "military-grade" countermeasures, he'd go bankrupt..

As someone pointed out elsewhere, though, drones that can carry enough explosives, on the other hand, are not cheap.

But drones that can be made up to look like they are drones that can carry enough explosives when seen from a bit of a distance is another matter.

The payload is cheap compared to delivery and control.

If you have a type of drone that can carry a useful payload (shaped charge powerful enough to disable a tank, in the ballpark of 5-10 kg, is not that feasible for a small drone - but a something like a frag grenade may be feasible), then you might as make them all real, the dummies would cost almost the same.

There was recent news about drone that could carry full sized movie camera. Price was few thousands for the drone.

If you go handgrenade size, the drone costs just bit over 100$.

A frag grenade costs something like $30 (and that's with military procurement overhead that would also raise the drone price to $300; mass produced third world grenades cost $5-$10 to their armies); a detonator, explosives and ballbearings for a DIY modification to that drone would be much cheaper.

Anti-tank shaped explosive charge would be hundreds of dollars but again, a fraction of the drone cost.

If the drone system is capable of aiming, you might want to try this wrinkle: https://en.wikipedia.org/wiki/Explosively_formed_penetrator

The dummies don't need to be a type of drone that can carry a useful payload, that is the point. They just need to sufficiently resemble one for long enough that you have to shoot them down just in case.

The radar signature of a small projectile coming in at, say >30m/s is indeed a lot different from a running, tiny human. What about something like a soccer ball, though? It's a small-ish projectile, coming in quite slowly. What about a hand grenade?

Hopefully they test for this stuff and have a firm idea of where they want their thresholds but, then again, sometimes bugs happen. https://www.wired.com/2007/10/robot-cannon-ki/

I get the feeling that destroying a kids soccer ball thrown at a tank is the least of the kid's worries in that situation. I would assume it would only go active with the permission of the people in the tank.

These systems are set to ignore anything moving slower than 50 m/s or so. Even professionals can't kick a ball that fast. The lower limit is specifically set to avoid triggering the system on rocks, falling debris, birds, people, and anything else benign that might be moving in the area.

The problem is that a thrown hand grenade is detectable by the system, but well under the limit.

One publicized case of a soldier in a vehicle "protected" by this system but killed by a tossed hand grenade or hit by a grenade launcher from long range (ordinary 40mm grenades are only fired at about 75 m/s at the muzzle), and there will be calls for this value to be adjusted.

The system is also capable of detecting firearm projectiles, but is specifically tuned not to react. Regardless of what calls may come, there won't be a change because the designers and the customers have already considered that possibility and specifically excluded it as not being worth the risk. This is not a case of being too cheap or short-sighted to do something.

The system rightly should not react to tossed hand grenades or ordinary 40mm grenades, just as it shouldn't react to rifle rounds or thrown rocks - those grenades have no chance of penetrating the tank's armor anyway.

If soldiers are exposed, then such a system reacting is a greater threat to their lives than a hand grenade; triggering the system is quite likely to harm nearby troops.

These systems don't try to deal with grenades which aren't really a threat to anything with armor so the code can ignore anything that people could throw/kick really. What the APSs are designed to catch are RPGs and other anti-tank rockets which all travel >100 m/s which is well above what a playful kid can make.

rockets which all travel >100 m/s which is well above what a playful kid can make

Speak for yourself. I loved rockets[0] as a playful kid!

[0] https://www.estesrockets.com/

Even without this new system, a person setting a toy rocket off near a deployed military force is really asking for trouble.

I disagree. It is the deployed military force that is asking for and finding trouble. It is the innocent who bear the brunt of the danger for this. This is the moral hazard[0] of war.

[0] https://en.m.wikipedia.org/wiki/Moral_hazard

Possibly, though I bet the return from the cardboard/cardstock that most of those are made from are very different from the radar return from a metal missile.

I played with Estes rockets too. How many people are likely to in war zones like these APS devices will be deployed in are likely to though? The rocket motors aren't super cheap and aren't really reusable or easy to make your own.

The G in RPG is Grenade.

I think RPG actually stands for ruchnoy protivotankovy granatomyot

'rocket propelled grenade' is a backronym.

Uh, what do you think "granatomyot" means?

What do you think the rest of it means? According to Wikipedia[1], the phrase "ruchnoy protivotankovy granatomyot" means "hand-held anti-tank grenade launcher".

[1]: https://en.wikipedia.org/wiki/Rocket-propelled_grenade

There are hand-held grenade launchers, crew served grenade launchers, etc. None of which means it's a "backronym."

Sure it does. The acronym RPG literally comes from the phrase "ruchnoy protivotankovy granatomyot", which was the name given to a series of Russian weapons in the category of portable anti-tank rocket launchers. And this name definitely pre-dates "rocket-propelled grenade", and in fact predates the weapons being rocket-propelled at all. For example, the RPG-40 is simply an anti-tank hand grenade (https://en.wikipedia.org/wiki/RPG-40), or the RPG-43 (https://en.wikipedia.org/wiki/RPG-43) and RPG-6 (https://en.wikipedia.org/wiki/RPG-6).

Actually, looking at these sources, the non-propelled versions were actually called "ruchnaya protivotankovaya granata" ("hand-held anti-tank grenade"). Still the same acronym of course, it just doesn't include the launcher. So when the launcher part was added, the phrase changed slightly but the acronym remained the same. And it was only at this point that the phrase "rocket-propelled grenade" could be used to refer to this weapon, and the phrase was presumably created to match the acronym RPG.

The RP in RPG is Rocket Propelled. /pedantry

There's a huge difference between RPGs and hand thrown anti personnel grenades. The first uses a shaped charge to create a very directional blast of fast hot metal that can punch through armor and the latter is an unfocused omnidirectional blast that can't get through light armor.

>so most children or children-thrown objects would not be targeted.

>most

Great/s

This seems like a willful misinterpretation of the comment.

Do not mind the naysayers, they may be vocal now but Tsahal will also deal with them with equal retribution once the constant threat of palestinians is eradicated.

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