pixelsort
7 months ago
Mach 11 hypersonic missiles? Is it even possible to intercept something going that fast without your interceptor tearing itself apart?
openasocket
7 months ago
Absolutely! The US ABM shield is meant to intercept incoming ICBMs, which in terminal velocity will be in excess of Mach 20. The difficulty with speed isnt that the interceptor will “tear itself apart” it’s just that it means less margin for error when plotting your intercept course
stormfather
7 months ago
I bet there are nuclear tipped interceptors too, though that wouldn't be public. Its a lot easier to destroy the incoming missile if your margin of error is a few miles versus a few meters. Not to mention it would blot out all the multiple re-entry vehicles. The public wouldn't want to know that's the plan but it would sure beat nukes detonating in cities.
I even remember reading about how the Soviets planned to chain detonate nukes over Moscow in the event of an exchange to destroy incoming ICMBs.
openasocket
7 months ago
GMD is hit-to-kill. Though I should point out that it’s broadly useless.
GMD is only capable of taking out 10-20 missiles at once. Russia and China both have hundreds of missiles, and if the DPRK isn’t there yet they will be soon. GMD is essentially useless at preventing a first strike. It was ostensibly meant for if a rogue state managed to launch a handful of ICBMs at the US, a scenario that really isn’t likely. What it would be useful for, is if the US were to strike first and take out the majority of the enemy’s missiles on the ground. To be clear, I don’t think that is why the US built it, and that isn’t part of the strategic thinking. But that possibility is exactly what Russia and China suspect about GMD. Hence their expansion of new weapons.
stormfather
7 months ago
Yeah exactly. Shooting hundreds of bullets with your bullets. And each bullet you need to shoot breaks into smaller bullets upon re-entry that start randomly maneuvering. Hit to kill is just not practical against a peer firing hundreds of ICBMs.
That's why I suspect the US never stopped developing nuclear tipped ABMs with the Sprint I and II programs. They just went dark. It's the only logical way to defend against the only existential threat we face, and DC is gonna be first struck so you can bet the political class is incentivized to develop this.
Why keep it secret? Well first it interferes with MAD which is very destabilizing. Also its good to hold your most important cards close to your chest. And there's the fact that the public would be uncomfortable with the idea that our plan to survive involves so much radiation being thrown around. A lot of incentive to not talk about it...
openasocket
7 months ago
I don’t think that makes sense. Where are the vast stockpiles of missiles? The silos? The thousands of people who would need to be on ready alert to launch those missiles? This also would require the US to have been cheating on the START treaties and probably the ABM treaty when it was in effect as well.
Also, nuclear-tipped ABM systems aren’t some sort of super power. Remember that all of this is happening in space at very high speeds. The Nike Zeus had to get within a kilometer of the target warhead before detonating. It’s not like you could throw a couple of these up and knock hundreds of incoming warheads out of the sky.
LargoLasskhyfv
7 months ago
Not to forget: "Where are the rest of these?" https://en.wikipedia.org/wiki/Safeguard_Program#/media/File:...
Or is there another option now, with the necessary coverage? From space, via SAT? Some sort of 'dent-detection' in the electromagnetic field instead, be it natural, or man-made?
gs17
7 months ago
Nuclear armed anti-balistic missiles have been made, but they're not in use as far as we know. https://en.wikipedia.org/wiki/Sentinel_program Spartan missiles were set to be armed with 5 MT warheads!
user
7 months ago
maxglute
7 months ago
AFAIK US doesn't have any ABM system that can intercept mach 20 ICBMs, let alone in terminal phase. The closest was FTM-44 in 2020 that hit an "ICBM representative" target midcourse in "highly favourable", i.e. not operational conditions. Which doesn't reveal speed of mock target, but IIRC there was testimony to subcommittee on strategic forces a couple years ago where director of missile defense stated US does not have systems to track "much less intercept" missiles going at mach20, suggesting limits of current capabilities. I would guess not much more than mach10, seeing how few Fattah 1s (mach10-15) were not intercepted in last round of ballistic attacks against Israel in October, where USS Bulkeley (which has ANSPY6V1 / aka highend AEGIS BMD) was trying to shoot them down with SM3s. Granted we don't know interception % of Bulkely, or how many they tried to intercept, but a lot of "high"end Iranian missiles (really medium tier) got through.
LargoLasskhyfv
7 months ago
It could have, something like this, just more modern: https://en.wikipedia.org/wiki/Sprint_(missile) <- Tip glowing white hot while ascending with 100Gs. Whee!
Combine this with facilities like these https://en.wikipedia.org/wiki/Safeguard_Program and have modular mini nuke breeders on site, powering atmospheric capture of CO² to turn them into synthetic fuels. Pharaonic Profits!1!!
maxglute
7 months ago
Shooting down nukes with mini nukes during terminal interception, i.e. over your soil is probably only going to fly during cold war hysteria. Safeguard was about protecting nukes in silos before SSBNs added survivability to triad.
I suggest: https://cnc.fandom.com/wiki/Firestorm_wall_section
LargoLasskhyfv
7 months ago
Unconvinced :) Maybe something more like this? https://duckduckgo.com/texas+tesla+tower
But this still has to get reliable ännärdshy from somewhere, so the possible synergy between modular mini nuke plants to power on site atmospheric capture of CO² to produce clean synfuels still applies!1!!
Or maybe we could have an HVTC (High Voltage Teslatronic Current) atmospheric supersmartgrid, made out of a network of these.
(Bzzzt Brrzzzzt Bzzzt Brrzzzzt)
moralestapia
7 months ago
Has it been demoed/tested against hypersonic missiles?
openasocket
7 months ago
Ugh, I really hate that term. “Hypersonic” just means traveling faster than 5 times the speed of sound. We’ve had ballistic missiles capable of exceeding that speed since the 1950s. ICBMs are hypersonic. So, yes, GMD has been tested against hypersonic missiles.
The latest hype is around “hypersonic glide body” type weapons. Where instead of traveling a straight ballistic trajectory they have small control surfaces and are capable of maneuvering. Ironically, though, having to maneuver like that makes such missiles slower, not faster, than an equivalent ballistic missile. And their maneuverability isn’t exactly huge, because at those speeds even small turns will impose significant g forces. So there’s this weird tradeoff between speed and maneuverability.
LargoLasskhyfv
7 months ago
Hm yes, but depending on course/great circle distance ballistic missiles have an apogaeum between 1200km to 4500km. While anything which is 'boosted back down there' during ascent reaches maybe 300km max height, then doing 'skip reentry' stuff and/or powered steering at 100km to 200km. Which is less distance to cover.
ttyprintk
7 months ago
I think the question was about hypersonic cruise, specifically whether ABM systems can detect a signature.
moralestapia
7 months ago
Ever since HN was taken over by LLMs you bump into these sort of arguments regularly. Indeed, it is pretty obvious how a real human would have interpreted and answered the question.
I wish HN had a "flag as LLM" button.