Hypersonic HAWC missile flies, but details are kept hidden • Hacker News Board

Re: Hypersonic HAWC missile flies, but details are kept hidden

#191

Post by sudosysgen » Wed, Sep 29, 2021, 7:43 PM UTC

baybal2 wrote: post #190

sudosysgen wrote: post #173

Earlier quoted context omitted.

Really not. Hypersonic missiles are a game changer because, without any risk of escalation, they are un-interceptable and can hit very important and high value assets very fast without requiring survivable targeting platforms.

If somebody takes out the GHQ of a superpower tomorrow with this, that is certainly "very escalateable," but unlike other options it still requires conventional follow up to deliver defeat, and keep the enemy occupied in immediate aftermath. And it surely lacks the intimidation factor of a massive nuclear ballistic missile attack. No amount of surgical strikes will be enough to behead a well trained military of a sup…

No one is trying to invade a superpower. Certainly not China.

The point of hypersonic missiles is to paralyze the force projection abilities of an exceptionally powerful military. For that striking only 30-40 very high value targets is enough.

Re: Hypersonic HAWC missile flies, but details are kept hidden

#192

Post by 2OEH8eoCRo0 » Wed, Sep 29, 2021, 9:08 PM UTC

sudosysgen wrote: post #180

2OEH8eoCRo0 wrote: post #39

Earlier quoted context omitted.

How are the hypersonic missiles guided and what is their range?

They are guided by active radar, passive radar, and optical sensors. Their range is anywhere from 5000-700km, but many can be air-launched.

If they are hypersonic in the atmosphere then they have radio opaque plasma around them. How do they transmit and receive radar pulses? How do they see with optical sensors?

Re: Hypersonic HAWC missile flies, but details are kept hidden

#193

Post by throwawaylinux » Wed, Sep 29, 2021, 9:24 PM UTC

kubanczyk wrote: post #168

throwawaylinux wrote: post #150

Earlier quoted context omitted.

> No, armies do not have their finger on nuclear trigger with a time horizon of 30-ish minutes. > We are not in the 1960s when at times it was literally true. You are claiming that not only China, but the US and Russia don't have the capability of launching strikes from 30 minutes? (i.e., well beyond the time to respond to ballistic missile launch detection)? Do you have a source for this? This doesn't appear to agre…

Yes, I was writing about launch-on-warning posture although I can now see I could have been more clear. As far as I know no country is presently assuming that it is able to detect, interpret, and authoritatively decide to enter full-scale nuclear war within ~25 minutes of enemy ICBMs' launch. (Leaving say ~5 minutes to implement the decision.) What you cited is sad, but firstly it is still an "ongoing debate", and se…

> Yes, I was writing about launch-on-warning posture although I can now see I could have been more clear. As far as I know no country is presently assuming that it is able to detect, interpret, and authoritatively decide to enter full-scale nuclear war within ~25 minutes of enemy ICBMs' launch. (Leaving say ~5 minutes to implement the decision.)

Do you have a source for that?

The sibling comment says Russia and USA have a prompt alert which can launch in under 15 minutes. Other articles say the US president could be contacted and approve in under 30 seconds, not sure how the Russian chain of command goes.

The decision process does not begin when nukes are detected of course, that's the end of the process. Pre agreed criteria have already been met. Quite likely there is no decision about entering a full scale nuclear war because they are already in one.

Re: Hypersonic HAWC missile flies, but details are kept hidden

#194

Post by throwawaylinux » Wed, Sep 29, 2021, 9:32 PM UTC

zardo wrote: post #171

throwawaylinux wrote: post #128

Earlier quoted context omitted.

> It's worth noting that at these speeds a "long" period need only be ~1 hour to reach a target from launch. A flight from Hawaii to Taipei would be 1.3 hours at Mach 5, and 54 minutes at Mach 7. > These weapons represent an ability for both the US and China to conventionally intervene from their mainlands to any location within the Pacific. Is that the kind of range these have? Almost 9,000 miles from LA to the Sout…

>Ballistic missiles of course have these kind of ranges and can carry conventional payloads. Just call while the missile is on the way to let the people it's going to kill know its not a nuclear bomb headed their way so they shouldn't fire a nuclear bomb back.

On the same call you could also tell them not to worry about the nuclear capable hypersonic intercontinental cruise missile that's on the way.

Re: Hypersonic HAWC missile flies, but details are kept hidden

#195

Post by sudosysgen » Wed, Sep 29, 2021, 9:37 PM UTC

2OEH8eoCRo0 wrote: post #192

sudosysgen wrote: post #180

Earlier quoted context omitted.

They are guided by active radar, passive radar, and optical sensors. Their range is anywhere from 5000-700km, but many can be air-launched.

If they are hypersonic in the atmosphere then they have radio opaque plasma around them. How do they transmit and receive radar pulses? How do they see with optical sensors?

That is not how plasma stealth works. The temperature of the plasma determines the minimum frequency of RF that gets through.

So you have to use a higher frequency radar and make sure the temperature of the plasma is not too high in front of the radar. You don't have to put the radar on the nose.

For optical sensors you would be imaging off-axis. So you can put the sensors pointing, say, 30 degrees below forwards relatively far back and there will not be much plasma in front of the sensors as it comes from compression and not friction.

There's a NASA PDF floating around that cites ~7000 K as the temperature of a plasma in front of hypersonic aircraft and concludes that radar is feasible then.

Re: Hypersonic HAWC missile flies, but details are kept hidden

#196

Post by post_from_work » Thu, Sep 30, 2021, 12:21 AM UTC

sudosysgen wrote: post #183

post_from_work wrote: post #119

Earlier quoted context omitted.

The US Navy does shock tests, where it detonates large explosives underwater close to its carriers, for exactly this reason. These ships are way more durable than you give them credit for. https://www.thedrive.com/the-war-zone/41181/shocking-images-...

Lol, no. The water stops explosions. A direct hit by a 10 ton mass going at Mach 7 will destroy any ship . the Navy won't make tests for that because it's a foregone conclusion.

>>>The modern one probably won't survive a drop less than 1 meter.

That link was more in response to the assertion "The modern one probably won't survive a drop less than 1 meter.", suggesting that warship-grade computer and electronic systems are vulnerable to mild shock damage.

And the Navy has, in fact, done a SINKEX on a carrier: https://www.thedrive.com/the-war-zone/22639/this-is-the-only...

The results are classified. Considering how the flight deck and upper works look pretty much intact, they probably hit it with multiple torpedoes rather than anti-ship missiles.

Re: Hypersonic HAWC missile flies, but details are kept hidden

#197

Post by sudosysgen » Thu, Sep 30, 2021, 1:37 AM UTC

post_from_work wrote: post #196

sudosysgen wrote: post #183

Earlier quoted context omitted.

Lol, no. The water stops explosions. A direct hit by a 10 ton mass going at Mach 7 will destroy any ship . the Navy won't make tests for that because it's a foregone conclusion.

>>>The modern one probably won't survive a drop less than 1 meter. That link was more in response to the assertion "The modern one probably won't survive a drop less than 1 meter.", suggesting that warship-grade computer and electronic systems are vulnerable to mild shock damage. And the Navy has, in fact, done a SINKEX on a carrier: https://www.thedrive.com/the-war-zone/22639/this-is-the-only... The results are clas…

Carriers are not vulnerable to a meter drop, but it's objectively true that ships are not built to the same standards nowadays as they used to be.

In WW2 ships were built to remain operational after multiple direct strikes. Nowadays ships are built to not sink after a single direct strike at the most like carriers, or only mildly though against such a hit because actually dealing with it would make them orders of magnitude more expensive and so heavy they'd be useless.

While a WW2 battleship could survive multiple direct hits and still fulfill its mission, a modern carrier would be lucky not to sink, and definitely won't be launching and recovering aircraft.

If a carrier in a war against a major power can't launch any aircraft anymore it's as good as dead, once it's off the AA ships will be targeted and sunk as they won't have AWACS and fighters to defend them and the carrier itself will be destroyed by enemy air power.

But the commenter is absolutely correct, ships are not expected to remain operable after a direct strike anymore. Weapons have gotten so good that defending credibly against them is not practical, so it's not really worth it to protect them nearly as much as it used to be.

Re: Hypersonic HAWC missile flies, but details are kept hidden

#198

Post by varjag » Thu, Sep 30, 2021, 6:31 AM UTC

dirtyid wrote: post #186

varjag wrote: post #165

Earlier quoted context omitted.

I mean, sure: that's what my original point was, it's not just nuking the carrier group. China knows the dynamic, the likely escalation route from that and it knows at the end of it, it lays in radioactive ruin. Nuking is just not an option; even a conventional attack (with much less guarantee of success) is already a pathway to full scale war, just not immediately nuclear.

> not just nuking the carrier group US/USSR were prepared for theatre level nuclear engagements, as long as not on USSR or US soil. I would not dismiss trading tactical nukes on third party soil if things get desperate. PRC SCS islands, US indo-pac bases, carrier groups are no brainers. Up to US bases in Japan and Australia. I think we dismiss low level nuke engagement at peril, any competent war planner will keep it…

> PRC SCS islands, US indo-pac bases, carrier groups are no brainers.

PRC SCS islands are sand piles with a couple of barracks and a landing strip, that would not be an equal trade for a carrier group.

> US/USSR were prepared for theatre level nuclear engagements, as long as not on USSR or US soil.

I dunno what America was prepared for, but I was in USSR at the time and the public message was any nuclear confrontation will end up being a total one.

Re: Hypersonic HAWC missile flies, but details are kept hidden

#199

Post by dirtyid » Thu, Sep 30, 2021, 8:11 AM UTC

varjag wrote: post #198

dirtyid wrote: post #186

Earlier quoted context omitted.

> not just nuking the carrier group US/USSR were prepared for theatre level nuclear engagements, as long as not on USSR or US soil. I would not dismiss trading tactical nukes on third party soil if things get desperate. PRC SCS islands, US indo-pac bases, carrier groups are no brainers. Up to US bases in Japan and Australia. I think we dismiss low level nuke engagement at peril, any competent war planner will keep it…

> PRC SCS islands, US indo-pac bases, carrier groups are no brainers. PRC SCS islands are sand piles with a couple of barracks and a landing strip, that would not be an equal trade for a carrier group. > US/USSR were prepared for theatre level nuclear engagements, as long as not on USSR or US soil. I dunno what America was prepared for, but I was in USSR at the time and the public message was any nuclear confrontatio…

It's not an equal trade, but it's as close to proportional tactical/theatre level nuclear retaliation as US can get, PRC simply doesn't have many overseas bases / vunerabilities for US to target. Vast majority of PRC forces are on the mainland which is... basically the top of the escalation ladder, and opens up CONUS + territories for proportional retaliation.

Otherwise, SCS bases are substantial forward deployment positions for PRC. Conventionally neutralizing SCS bases would require 100s of ordnance from naval platforms in a mostly secondary theatre - substantial amount of what US can concentrate in region. The bases serve missile sinks by design. So in a sense, taking them out via tactical nuke versus expending significant in theater munitions is an appropriate trade.

>public message

There's a lot of (declassified) literature on nonstrategic nuclear weapons and scenarios, war plans for theatre level use in Europe and Asia. Here's a report from this July.

https://sgp.fas.org/crs/nuke/RL32572.pdf

Public messaging is going to play up MAD, but nonstrategic nukes has never been off the table. PRC has no first use, but one never knows. Especially since the engagements are likely maritime over empty waters, which has different escalatory potential than scenarios of nuking NATO/USSR buffer countries during cold war. It's not that I think it's likely, just the chances are less non-zero than what's publically presented, i.e. the 2021 report exists in the first place because US wonks are at least discussing tactical nukes which are not subject to arms control agreements.

Re: Hypersonic HAWC missile flies, but details are kept hidden

#200

Post by rini17 » Thu, Sep 30, 2021, 11:47 AM UTC

sudosysgen wrote: post #182

rini17 wrote: post #159

Earlier quoted context omitted.

Now notice how no one is going to "harmonize" you.

Not anymore that it is an unshakable fact and it doesn't matter what you think. Go back in 1790 or 1810 and see yourself jailed as a traitor.

Can you restate that? I honestly don't understand.