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dgroshev

1,776 karma · joined September 30, 2014

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dgroshev··on Artemis II safely splashes down
You're factually incorrect with most of your Kinzhal-related points.

Kinzhal is just an air-launched version of Iskander with a bit better energetics because of not launching stationary from the ground. It's not a magic superweapon.

Its terminal manoeuvring is hardly new, Pershing II was doing that back in the 70s.

The top speed of a ballistic missile (that you're citing) is not the same as its speed in the interception-relevant section of the flight, because atmosphere gets denser and slows missiles down (and manoeuvring slows MARVs down even further). The Ukrainian operators claim that the observed speed was close to Mach 3.6.

The primary interceptor for the higher energy Kinzhal would be THAAD, not PAC-3. Sadly, Ukraine didn't get THAAD.

"Plasma stealth" is a sci-fi fabrication. The US had no problem tracking ICBM RVs with their much higher speeds close enough for a direct hit during a Sprint test back in the 70s.

dgroshev··on Are We Idiocracy Yet?
I'm not being dishonest, I'm being sarcastic. Although I can see that you ignored everything else that I said.

I couldn't care less about "winning".

dgroshev··on Are We Idiocracy Yet?
"I'd love to hear any additional ideas except those that work everywhere because that'd require big changes"

The answer is trivial and well-known: federal-level gun controls (because anything state-level is a joke without hard borders between states), coupled with a buy-back program, amnesties, and real enforcement. There are no school shootings in the UK or Australia.

Unfortunately, there are too many people who'd rather have more guns and more dead kids (and adults) than fewer dead kids and fewer guns around. They'd justify that by talking about "preventing tyranny" or something, ignoring that paramilitaries executing people in broad daylight on camera with no consequences is already the reality of the US today, and guns played zero to negative role preventing that. Coincidentally, there are no such paramilitaries in the UK or in Australia either.

As for "the rights of citizens": there is no such thing as an immutable unconditional right. American citizens don't have a right to own nuclear weapons, neither should they, even though it's perfectly possible to have a very expansive definition of "bearing arms". Plus, the Constitution itself was amended many times in the past, and by now is clearly in need of a major overhaul, as evidenced by the US sliding down in various democracy indices (for example, World Press Freedom Index puts the US under Romania in 2025). So there is nothing impossible or uniquely oppressive about the reforms necessary to stop children being shot in schools, but because it's such a foundational element of identity for so many with a lot of money behind it (the NRA is exceptionally well funded), in practice there's indeed "No Way to Prevent This".

dgroshev··on Missile defense is NP-complete
Again, the unfairness goes both ways: RVs need to carry substantial payloads, whereas KKVs only need DACS and sensing. THAAD KKVs weigh about 50kg; most effective payloads, even nuclear, would weigh substantially more.

Hypersonic gliders can't be nearly as numerous as ballistic RVs because physics, and they are getting their own interceptor (GPI).

I think this conversation would benefit from splitting theatre ballistic threats (evidently, those are now being effectively countered without 30 to 1 ratios) from strategic threats. For strategic threats, the logic is substantially more complex: even 50% intercept rate greatly complicates counter-force strikes and is valuable. In practice, the rate is substantially higher than 50%.

Chevaline wasn't the only program, the US had its own they didn't end up deploying. Both countries concluded that effective decoys end up weighing roughly the same as warheads.

dgroshev··on Missile defense is NP-complete
That goes both ways. Terminal manoeuvring gets difficult as speeds increase, too. Besides, higher tier threats are intercepted outside the atmosphere, where it would be prohibitively expensive (in mass and accuracy) for RVs to manoeuvre.

Your SSPK is way WAY too low. Also, the math on interceptions changes completely with multiple KKVs per interceptor (see NGI).

Decoys don't work even at the highest end (ICBMs), see Chevaline's history and its rapid decomissioning for an example of just that.

dgroshev··on Missile defense is NP-complete
Not sure where the crucial SSPK number came from, given that the referenced link https://missilethreat.csis.org/system/gmd/ does not have neither the number nor data to calculate it. Even more importantly, using the test history too far back is incorrect, since the system was debugged and refined.

Also, a big omission in the post is NGI carrying multiple kill vehicles. Considering the relative cost of a launching system and a KKV, multiple KKVs flip the math quite significantly.

dgroshev··on Dune3d: A parametric 3D CAD application
G2 fillets are the next frontier. Even Fusion doesn't seem to handle them well. I mean they can be created without much drama, but geometry derived from them is very likely to fail with no real reason.
dgroshev··on 4Chan mocks £520k fine for UK online safety breaches
> recused itself

Surrendered.

dgroshev··on 4Chan mocks £520k fine for UK online safety breaches
> more or less politically, culturally, and economically irrelevant

I feel like we're reading different posts.

dgroshev··on 4Chan mocks £520k fine for UK online safety breaches
Is it indicative of "economic irrelevance"?
dgroshev··on 4Chan mocks £520k fine for UK online safety breaches
> the UK really heading quickly towards a Great Firewall

> top most read article on BBC News right now is yet another public sector cover up

Do you not see a tiny little bit of contradiction here (regardless of your mis-characterisation of the second link)

dgroshev··on 4Chan mocks £520k fine for UK online safety breaches
It's not "knocking the US", it's an example of the (likely, projected) decline. The size of the economy is an example of why "irrelevant" is delusional. Two different points.

The "prominent UK residents" don't "leave" the UK. Benedict Cumberbatch lives in London, despite constantly starring in Hollywood films. It's an example of the UK culturally punching way above its weight in proportion to its population.

dgroshev··on 4Chan mocks £520k fine for UK online safety breaches
We need to recognise the difference between the GP rant and what you're describing. The austerity is undeniably still reverberating through the country. It will take years for this ship to turn around, although it is being turned around. For example, in just about a month we're getting European-style rents with the Renter's Rights Act, which is transformational. We can and should do better, and everyone can contribute to solving those issues, but after a decade of nothing the necessary changes are finally being implemented.

But the rant is entirely counterfactual. Britain is a very rich country with beautiful and recovering nature, a healthy and educated population, one of the more capable armies in Europe, a functioning deterrent, and a relatively healthy political system. We just got two new parties becoming credible threats to the "main" two (regardless of the parties' views, the political competition itself is a much healthier situation than the American duopoly)! We just abolished hereditary peers, which is a constitutional change (and it can just be done)! Below the everyday media noise, we're doing alright as a democracy.

dgroshev··on 4Chan mocks £520k fine for UK online safety breaches
This is an entirely delusional twitter-brain take.

Despite its problems, the UK is still a sixth largest economy, a cultural powerhouse (how many Hollywood actors are British?), with a lot of soft power, a capable and currently renewed nuclear arsenal (Astraea and Dreadnought are on track), a globe-spanning network of alliances (from AUKUS to Japan deploying to the UK first time in their history to being one of the closest and most unwavering allies for Ukraine), and a constitutionally healthy and adaptive system of government (we just passed another constitutional change and it's not a big deal, we can just do that).

Frankly, this meme stinks of projection. Going from a shining city on a hill to a place where public executions by state backed paramilitaries are just another partisan talking point, that starts Special Military Operations with no plan or goal, that threatens to annex territory of its allies in about a year is an achievement. I guess projecting this free fall on the UK makes living through it more bearable.

dgroshev··on MoD sources warn Palantir role at heart of government is threat to UK security
GDS is amazing. However, unless we double/triple the GDS salary grades, it'll inevitably be hollowed out. From what I heard, that might've already happened.

Look for yourself, GDS is hiring a "Lead Technical Architect" for £67,126–£91,453 https://gds.blog.gov.uk/jobs/ . FAANG (and Palantir) pays up to triple that. How can GDS compete for talent?

dgroshev··on $96 3D-printed rocket that recalculates its mid-air trajectory using a $5 sensor
> It means doubling the transport capacity, but not doubling the burden

Which is my point, doubling the capacity at the end of the spear is more than double the burden. The scale is superlinear. The further out the front is (for the US, it's over at least one ocean), the more superlinear the scaling is.

> but it's not proportional to cost

You might've heard of the cheap North Korean shells exploding in barrels, destroying Russian howitzers. It is indeed very disproportional, that's why spending severalfold on better shells is a great tradeoff.

> You'd launch two at the same time to take the possibility of failure into account

It depends on the ability to launch two. Oftentimes it's impossible; cheap FPV drones interfere with each other, or maybe you don't have double the planes to fly CAS.

> how they are being employed today in Ukraine

It's logistically impossible to employ the kind of drones Ukraine is employing on the go and organically to infantry. Features and CONOPS that enable organic employment lead to a substantial increase in per-unit prices, see Rogue 1.

> A Magura isn't a missile, but it has shown its capability of completely shutting down the Black Sea Fleet.

It's three Black Seas worth of distance between Guam and the Taiwan strait. On top of that, nowadays those boats are pretty effectively countered. Overindexing on the war in Ukraine would be a mistake.

dgroshev··on $96 3D-printed rocket that recalculates its mid-air trajectory using a $5 sensor
To "look enough" like a missile that can hit something a hundred kilometres away with enough precision to not be ignored you need a missile that can fly a hundred kilometres. This is not cheap.

Instead of repeating myself, I'll just link a reply, if you don't mind: https://news.ycombinator.com/item?id=47389309

dgroshev··on $96 3D-printed rocket that recalculates its mid-air trajectory using a $5 sensor
AAA batteries don't have the current. Li-Ion is too fussy and has a pretty high self-discharge.

Ukraine can afford the cardboard boxes because they are fighting in their own country. The US has an ocean to cross.

Ukraine can get away with short shelf life because they are at war right now. The US has to stockpile because the supply chain has to run at some capacity in peace time to be able to ramp up quickly when needed, and discarding the produced ammunition after a year would be incredibly wasteful.

Neither Ukraine nor Russia can defeat each others' air defence networks. The US has a lot of experience doing just that, while successfully defending against ballistic missiles. High tier capabilities matter.

The Patriot in 1980 is a very different system from the Patriot that is fielded today. Between PAC-2 and PAC-3, AN/MPQ-65A and LTAMDS it's a cutting edge air defence system. The progress is constantly incorporated.

The Stinger is a bit old, but mostly because the US doctrine has few uses for it. Regardless, NGSRI is coming.

dgroshev··on $96 3D-printed rocket that recalculates its mid-air trajectory using a $5 sensor
It's an objective statement of their tactics, not something relative.

Modern precision guided weaponry is meant to selectively destroy military targets. WW2 style strategic bombing was targeting civilian populations mostly trying to disrupt industrial production in support of military action. Randomly firing a few unguided rockets into civilian population centres can't possibly achieve either. The only goal is to provoke terror in the civilian population, therefore it's a terrorist organisation.

You can see similar tactics in the "human safari" the Russians are running in several Ukrainian population centres.

dgroshev··on $96 3D-printed rocket that recalculates its mid-air trajectory using a $5 sensor
We're absolutely not running out of APKWS. They are manufactured by tens of thousands, and Hydra 70s are even more numerous.
dgroshev··on $96 3D-printed rocket that recalculates its mid-air trajectory using a $5 sensor
I don't understand your point. Sure, Ukraine can cut a few corners that western militaries are unwilling to cut. They still can't produce a domestic ballistic missile at scale, because it's genuinely hard, and simple terror weapons like Qassams are useless for militaries. "100 rockets for $10k" is off by orders of magnitude.
dgroshev··on $96 3D-printed rocket that recalculates its mid-air trajectory using a $5 sensor
GPS denial is a mixed bag. After about two years of efforts and counter-efforts, the Russians seemingly managed to build GPS receivers that are pretty resistant to jamming.
dgroshev··on $96 3D-printed rocket that recalculates its mid-air trajectory using a $5 sensor
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

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

dgroshev··on $96 3D-printed rocket that recalculates its mid-air trajectory using a $5 sensor
I'm just not sure what to even say when you're both so assertive and completely wrong. Please stop relying on twitter/reddit to inform your takes.

The war in Ukraine is being fought with all tiers of systems, ranging from Zircons and PAC-3 on the high end to booby traps on the low end. All of them are essential, and shortcomings on any of the tiers is ruthlessly exploited by the other side. Saying that it's only the small drones that matter betrays over-reliance on the gory FPV kill footage.

"QA, safety, blah blah blah" get implemented on every level as soon as it's feasible. You can just look at photos from Yelabuga and see how their assembly lines are not fundamentally different from Raytheon's. Ukraine is standardising their drone manufacturing. This is inevitable, because faulty munitions lead to

- killed friendly soldiers if the munitions explode pre-launch

- wasted logistic resources if they don't launch

- wasted time and targeting opportunity or friendly units not getting fire support when they fail after launch

The cost of faults is severe and much higher than just the cost of the munition itself.

It seems that you're misinformed about the real cost of modern FPVs used in Ukraine. Reports of sub-$1000 drones are years out of date and heavily relied on salvaged munitions, but there are only so many RPG warheads you can get for "free". Current FPVs are heavier, more capable, and cost a few thousand dollars. Further, it's reported that it takes dozens of FPVs to kill a single "hedgehog tank", which brings the total cost of one kill to a rough parity with "classic", "expensive" systems like the Javelin, except Javelins can be carried by a mobile squad, and launching FPVs requires a dedicated immobile unit with a long logistical tail.

Don't mistake forces not being ready to counter low-tier threats immediately with the threats being impossible to counter. Group 3 drones are very effectively countered in Ukraine, to the extent that it takes hundreds to deliver maybe a few TLAMs worth of payload to the target. There are mature systems being rolled out right now across western armies, from various gun-based solutions to APKWS. Group 2 drones are decimated with cheap anti-air drones. Group 1 drones are being handled with APSes, which work pretty well even in urban environments, as Israel has (very unfortunately) demonstrated lately.

dgroshev··on $96 3D-printed rocket that recalculates its mid-air trajectory using a $5 sensor
That's entirely possible, but doing so reliably and safely is difficult and expensive enough that for a very long time Ukrainians were accepting the risk instead.

The risk appetite countries in existential conflicts have is quite different from what we're used to. For example, there are plenty of videos of Ukrainian soldiers angle grinding cluster munitions open to extract submunitions to put on drones, but that's not a strategy that western armies can rely on.

dgroshev··on $96 3D-printed rocket that recalculates its mid-air trajectory using a $5 sensor
> TFA is literally about a $96 rocket

It's a firework-grade rocket with no payload that can't even ignite reliably.

To imitate even a TBM or a MBRM, you need similar kinematics, even if you're running without a payload. Maybe your solid rocket motor would be a touch smaller because you're not delivering hundreds of kilograms of explosives, but it still has to be large because of the rocket equation. With a large motor you're looking at a lot of damage if it explodes at the launch point, so you need quality casting. You can't really save much money on the motor.

Then, you need a TEL. Because the motor is large, the launcher has to be comparable to the real thing. You probably don't want to have two different vehicles, so you keep the same vehicle; it needs to be armed, driven around, and set for launch. Not that different from the real thing.

So you've done all of that, and then you realise that your empty warheads are too light and the missiles (or warheads, if you split) don't interact with the atmosphere in the same way as non-decoy missiles do. What's worse, modern radars are perfectly capable of noticing that and discriminating the decoys. All of that effort, and you didn't win anything. Might as well add the payload.

The US and the UK spent vast amount of money chasing exactly your line of reasoning with nuclear warhead decoys. Chevaline is a culmination of the effort, and it's retired for 30 years. In the end, relying on decoys doesn't really work, they are too expensive.

Fancier CPUs change very little of this calculation, because compute is a very little part of the cost to begin with.

dgroshev··on $96 3D-printed rocket that recalculates its mid-air trajectory using a $5 sensor
Ukraine does bother with all of that when they can afford it. I'd even say that FPV drones are the main exception, and only because Ukraine was so pressed for immediate results and had stockpiles to repurpose. There are only so many old RPG warheads you can reuse with a detonator made of live wires, and maiming your own launch crews because someone made a tiny wrong movement arming their thirtieth drone of the day under artillery fire gets old fast.

Hezbollah is a terrorist organisation, they don't need their contraptions to work reliably. GMLRS serves an entirely different purpose to rockets made of repurposed telephone poles, and is much more useful for a military force.

Also, don't forget the distances. Ukraine is fighting a war in their own country, with direct ground lines of communication to the frontline. On the other hand, you can fit three Ukraines just between Guam and Taiwan.

dgroshev··on Kuwaiti F/A-18's Triple Friendly Fire Shootdown Gets Stranger by the Day
None of those articles elaborates on how that particular target was selected, which is the claim the GP made. There's a difference between "Pentagon uses AI for targeting" and "AI selected a school as a legitimate target".

Ted Bundy drove a car. Cars kill people. Doesn't mean that Ted Bundy was killing people by running them over.

dgroshev··on $96 3D-printed rocket that recalculates its mid-air trajectory using a $5 sensor
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 specification every time. You can stockpile the packaged missiles in a non-climate-controlled shed for years, replenish them at sea while being showered with salt water, subject them to shock of a nearby blast while in a VLS, and they will still launch, go up to Mach 13, and catch an incoming ballistic missile nearly every time.

Sure, Iran's ballistic missiles are simpler than SM-3, but they are still subject to most of the constraints. They still need perfectly cast large size solid rocket motors that don't crack after being stored for a year, they need warheads that only go off when they are supposed to, they still need to trace every part for QA, etc. There's a vast gap, largely invisible to amateurs, between garage prototypes and stockpiled AURs.

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