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$96 3D-printed rocket that recalculates its mid-air trajectory using a $5 sensor

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Re: $96 3D-printed rocket that recalculates its mid-air trajectory using a $5 sensor

#281

Post by halflife »

hermitcrab wrote: post #224
pjc50 wrote: post #198

Earlier quoted context omitted.

> price floor is not dictated by the electronics (which did get cheaper), it's dictated by the rest of the system: propulsion, warheads, arming and safety, QA, traceability, climate and shelf life stability. I wonder how much of that Ukraine is bothering with. Or Iran. Certainly Hezbollah are building down to a budget.

I wonder how many Hezbollah rocket operators get blown up by their own rockets? A not insignificant number, I suspect.

Last week they launched 200 rockets in the span of one day, about 40 of those fell inside Lebanon border, that’s not counting the number of rockets that did not fire at all.

Re: $96 3D-printed rocket that recalculates its mid-air trajectory using a $5 sensor

#282

Post by snitty »

ralferoo wrote: post #238

I remember an anecdote our robotics lecturer told our university class in 1995, which was about how in the west we try to make expensive things that are the absolute best of technology and how the other side didn't have that luxury and relied on ingenuity. He described a cold war Russian missile they had somehow obtained and were tasked with trying to reverse engineer. Ostensibly, it was thought to be a heat seeking…

This is shockingly similar to microbial motility mechanisms. Like random walk plus chemotaxis.

Re: $96 3D-printed rocket that recalculates its mid-air trajectory using a $5 sensor

#283

Post by nippoo »

redgridtactical wrote: post #151
hrmtst93837 wrote: post #46

Earlier quoted context omitted.

[flagged]

For a sub-minute flight the drift budget is actually pretty forgiving — a MEMS gyro drifts maybe 1-3 deg/sec, and if you're fusing with accelerometer data you really just need "which way is up" and "am I still pointed at the target." A $5 IMU can hold that for tens of seconds. Where you're right is repeatability. Mil-spec works the same on launch 1 and launch 500 across temperature extremes. Consumer MEMS you'd need…

Good $3 MEMS gyros are about 100x better than that now - look at anything new made by Invensense in the past couple years. And their drift is pretty Gaussian-distributed, so the error scales as sqrt(n). If you combine 8+ of them on one board you can get about 5deg/hour stability...

Re: $96 3D-printed rocket that recalculates its mid-air trajectory using a $5 sensor

#284

Post by dgroshev »

computerdork wrote: post #269
kdheiwns wrote: post #263

Earlier quoted context omitted.

If you think shelf life, QA, safety, blah blah blah matters when a rocket is 100 bucks, I have just three words: you will lose. The Ukraine war is being fought with a bunch of cheap toy style drones dropping grenades everywhere. The US got their bases blown to pieces across the Middle East by cheap drones that gently float through the air like a paper airplane in comparison to absolutely any missile. And let's not fo…

You have a point - cheap drones have changed warfare - but you might be simplifying the issue. As some warfare experts online have discussed, it isn't that cheap drones are the only weapon that is used in Ukraine (or warfare in general), it is one option in vast array of options based on the situation (although, agreed, it is taking on a much bigger significance). Look at the war in Iran. They did a pretty standard p…

It's fairly important to distinguish what kind of drones are we talking about [1]. Iran's using Group 3 drones.

The GP is confusing Iran's neighbours not being ready to counter group 3 drones with the drones being inevitably effective. These drones are by necessity large and slow, because they need a lot of energy and aerodynamic efficiency to get their range. That means that they are vulnerable to cheap counters, which Ukraine is demonstrating very convincingly: even though Russia is now launching 800+-drone raids, the vast majority is shot down.

Even when those drones do get through, they are extremely inefficient. It's not just that they can't carry a heavy or sophisticated payload (more complex warheads are more effective, but way more expensive), the extremely high attrition ratio forces the enemy to try to target way too many drones per aimpoint. Instead of serving a few hundred aimpoints, the 800-strong raid is forced to concentrate on just a few, otherwise most aimpoints will get no hits whatsoever.

But also the only reason 800-strong raids can even be launched is Ukraine lacking the capability to interdict the launches. 800 group 3 drones have an enormous logistics and manufacturing tail, which a Western force would have no problem destroying way before the raid can be launched. For example, Iran in its current state can't launch such raids. So in practice Iran's neighbours would need to intercept only a handful of drones, which is hardly an insurmountable challenge.

[1]: https://mwi.westpoint.edu/wp-content/uploads/2024/05/FL1.jpg

Re: $96 3D-printed rocket that recalculates its mid-air trajectory using a $5 sensor

#285

Post by itsthecourier »

mda wrote: post #276
einpoklum wrote: post #48

Earlier quoted context omitted.

I am completely against the US-Israeli war on Iran. That said, they are not carpet-bombing Iran. That is, they appear to be selecting individual targets rather than engaging in carpet bombing entire areas: https://en.wikipedia.org/wiki/Carpet_bombing The choice of targets is not legally legitimate (and the entire campaign is illegal AFAICT), and sometimes they used old/invalid intel, like what happened with that girl…

[flagged]

[flagged]

Re: $96 3D-printed rocket that recalculates its mid-air trajectory using a $5 sensor

#286

Post by esseph »

regularfry wrote: post #223
dgroshev wrote: post #115

Earlier quoted context omitted.

100 rockets for $10k is not happening. The price floor is not dictated by the electronics (which did get cheaper), it's dictated by the rest of the system: propulsion, warheads, arming and safety, QA, traceability, climate and shelf life stability. Take a look at Raytheon's manufacturing line: https://www.youtube.com/watch?v=kCCkVAHSzrc That's what it takes to have missiles that are nearly guaranteed to perform to sp…

Without necessarily disagreeing with your point, the driving consideration for Raytheon's production line is arguably not reliability. It's being able to charge the customer for perceived reliability. It's very hard to know from the outside how much of it is theatre, even if earnestly arrived at. There are incentives for these things to be expensive.

The US military is not "new" at this. There are whole career professions in the military around just this topic.

Re: $96 3D-printed rocket that recalculates its mid-air trajectory using a $5 sensor

#287

Post by srean »

redgridtactical wrote: post #253
tclancy wrote: post #38

Earlier quoted context omitted.

> The gap between consumer electronics and mil-spec capability keeps shrinking My friend's brother works in munitions and had, in his spare time, designed and prototyped a missile that could be built for about 10k. He pretty much was ignored by the contractor he works for. Shockingly, as of a couple weeks ago, they are all hot and bothered to talk.

That tracks. The defense primes have zero incentive to make things cheaper — their business model is cost-plus. A guy building something for 10k in his garage is an existential threat to programs billing 500k per unit. Of course they ignored him until the geopolitical situation made it impossible to keep ignoring.

> That tracks. The defense primes have zero incentive to make things cheaper

Same in medical imaging industry.

Re: $96 3D-printed rocket that recalculates its mid-air trajectory using a $5 sensor

#288

Post by dgroshev »

littlestymaar wrote: post #278
kdheiwns wrote: post #263

Earlier quoted context omitted.

If you think shelf life, QA, safety, blah blah blah matters when a rocket is 100 bucks, I have just three words: you will lose. The Ukraine war is being fought with a bunch of cheap toy style drones dropping grenades everywhere. The US got their bases blown to pieces across the Middle East by cheap drones that gently float through the air like a paper airplane in comparison to absolutely any missile. And let's not fo…

So much this. Reliability and durability only matters because the thing costs a million dollar a piece. When you have stuff with a mere 5-digits price tag or less, you simply don't care if half of them miss their mark or doesn't fire 10% of the time.

Half of munitions missing means doubling the logistical burden of delivering the munitions to where they need to be employed. The trucks/plains/ships that carry your munitions need to be fuelled and protected, too, so the expense is super-linear, especially when it's a distant war and not a war fought on the country's own soil, like in Ukraine.

Cheap munitions sometimes explode before they are launched, killing crews and destroying platforms.

Cheap munitions mean that CAS is a roulette. You waited for ten minutes for a support fire mission? Sorry, wait for ten more, whatever we launched has failed. Or maybe you're dead because the munition has hit you instead.

Cheap munitions can pin you down. Those cheap FPV drones that are supposedly cheaper than Javelins require dedicated immobile units to launch and guide to targets. Javelins are organic to infantry squads.

Cheap munitions are either very expensive or impossible. There's no cheap anti-ballistic missile and no cheap missile that can sink a warship in the Taiwan strait when launched[*] from Guam.

[*]: alright alright an LRASM would need to be flown closer by an F-35 but the point still stands

Re: $96 3D-printed rocket that recalculates its mid-air trajectory using a $5 sensor

#289

Post by trhway »

ralferoo wrote: post #238

I remember an anecdote our robotics lecturer told our university class in 1995, which was about how in the west we try to make expensive things that are the absolute best of technology and how the other side didn't have that luxury and relied on ingenuity. He described a cold war Russian missile they had somehow obtained and were tasked with trying to reverse engineer. Ostensibly, it was thought to be a heat seeking…

that sounds like crude-fied version of first Sidewinders.

Re: $96 3D-printed rocket that recalculates its mid-air trajectory using a $5 sensor

#290

Post by smileysteve »

kdheiwns wrote: post #263
dgroshev wrote: post #115

Earlier quoted context omitted.

100 rockets for $10k is not happening. The price floor is not dictated by the electronics (which did get cheaper), it's dictated by the rest of the system: propulsion, warheads, arming and safety, QA, traceability, climate and shelf life stability. Take a look at Raytheon's manufacturing line: https://www.youtube.com/watch?v=kCCkVAHSzrc That's what it takes to have missiles that are nearly guaranteed to perform to sp…

If you think shelf life, QA, safety, blah blah blah matters when a rocket is 100 bucks, I have just three words: you will lose. The Ukraine war is being fought with a bunch of cheap toy style drones dropping grenades everywhere. The US got their bases blown to pieces across the Middle East by cheap drones that gently float through the air like a paper airplane in comparison to absolutely any missile. And let's not fo…

It's even worse when your goal is commercial viability of carrying a relatively flammable liquid.

Tankers moving at a slow speed, across a narrow strait.

They don't have to sink to not be commercially viable; a few deck fires negatively impact your days at sea without incident.

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