Comment by credit_guy | Hacker News Reader

Comment by credit_guy | Hacker News Reader

Elon Musk may or may not know it yet, but his biggest contribution to humankind will not be that the Starship will take us to Mars, or that Tesla will help us shake off the dependency on fossil fuels. His biggest contribution will be to bring the end of the MAD world. The Mutually Assured Destruction world in which the majority of the living people were born, and never thought it will ever end.

You see, in the '80s the US had a missile defense idea called Brilliant Pebbles [1]. Basically they would put about 10k to 100k small missiles in orbit and these missiles would detect ICMB launches and go and destroy them. The problem was the economics of the system. It was simply too expensive. And because of that it was very easy to counter it: it was cheaper to build a few additional ICMBs than to add the necessary "pebbles" to neutralize them.

But SpaceX changed this calculus. It's now much easier to put things in LEO. And it will become cheaper still. It is very likely that in 10 years the Brilliant Pebbles will become economical. And if they do, they become obligatory. Because it will be only a matter of time until Russia (or maybe China) builds the capability of cheap space launches that will match SpaceX. And if they do, and build the Brilliant Pebbles first, then the US will find itself in a very unenviable position.

So in a very near future someone from the Pentagon will approach Elon Musk with an offer he won't be able to refuse. And why would he? Being part of the thing that ends the MAD will be certain to net him a Nobel Prize for Peace. And he will definitely be worth it.

[1] https://en.wikipedia.org/wiki/Brilliant_Pebbles

I'd expect such a system to severely ramp up tensions during development. "Our nukes are about to be useless, and theirs will work fine" is not a great thought to have in an adversary's mind for a 5-10 year period.

This is also is in line with the Russian objection to the the US wanting to convert some of their SSBNs to fire conventional warheads, to paraphrase their response “we won’t be wasting time trying to figure out what was launched and where is it heading”.

Unlikely. Russia's SS-18, a.k.a. Voevoda, a.k.a. Satan, a.k.a. R-36 - a big liquid fuel ICBM - are also known as Dnepr, a launcher which worked in Kosmotras. USA didn't have a problem with that.

Eh? We’re talking about launching Trident from a sub with a conventional warhead instead of a nuke.

There is a huge difference between using an ICBM as a SLV platform and using your nuclear triad.

Isn't this essentially triggering another arms race? The US finding a way to way counteract MAD means that the nukes China, Russia, etc have are all useless in an attack against US meaning now there is an arms race to develop something that can fight against the "Brilliant Pebbles" which will the force the US to come up with something that fights against that and so on.

MAD has allowed for peace in our time. Yes, the world has problems but its significantly better now than before. Maybe its best to remain in this condition.

I think we’ve always been in an arms race. Sometimes it’s money and not lives or power but we’re always struggling to one up everyone else.

Sure. But we aren't building more nukes. Breaking MAD means breaking the one fundamental principle/fact that has truly meant peace for quite a few years now. If we could maintain or improve this level so that wars are much less commonplace, that might just mean that we as a species might be able to move on from this petty warfare and actually work together.

Uh, we are: https://www.defensenews.com/smr/nuclear-arsenal/2020/02/04/t...

Not really. These are older warheads with a dialed-down yield. https://en.wikipedia.org/wiki/W76

If orbit gets weoponized to counter ICBMs it just sounds to me like midrange missiles from subs and allied countries are going to have a rennaissance. Basically the clock is going to reset back to the 60s. Then, ICBMs are probably going to get their own defenses against pebbles so you'd need more and more of those, until orbit is so full that space becomes inaccessible (Kessler syndrome).

> Isn't this essentially triggering another arms race

Where did you get the impression that arms races ever stop?

An arms race is a problem if it drains the resources of both participants. But the situation is so unequal here that this "arms race" would be more akin to a checkmate in one. Imagine this arms race would force both Russia and the US to invest $100BN more annualy in nuclear weapons. That would be economically devastating for Russia (who has a current defense budget of about $65 BN), and it would barely register for the US, with a current defense spending of $700 BN.

And then then our adversaries build endoatmospheric hypersonic weapons and robotic doomsday submarines and nuclear powered cruise missiles (all of which Russia is doing or has done), and we're back to square one.

Best answer to my admittedly wild hypothesis. Yes, this would be the correct response from Russia. But it's quite likely the US would find that a much easier thing to deal with than the ICBMs (and SLBMs) were for the last 60 years.

1. Hypersonic weapons. They don't have enough range. The Russian officials claim the Kh-101 missile has a range of 4500km, but it's more likely it's about 1500 km. That's quite bad, but defenses can be set up 2. 100 MT TNT autonomous submersible drones. To have their purported devastating effect, they need to blow up close to the shore, otherwise they don't create a huge tsunami. It's not a slam dunk that the Russians are able to sneak in such a drone close to the US shores. 3. Nuclear powered cruise missiles. They do have the range, and they appear quite scary. If Russia makes advances in this, it would be a benefit for humankind, as this technology could be used in space exploration. The MAD doctrine could be alive and well, but we'd end up with a powerful new tool in our toolbox for exploring the Solar system. Elon Musk would not be very upset.

ICBMs are old hat. Expect hypersonic scramjets to ratchet things up a notch. A country will have less than a 5 minute window to press their red button in the event of an alert. Not looking forward to this.

Get a robot to monitor your sky defense network.

Hypersonic weapons are slower than ICBMs btw. You’re not comparing apples-to-apples.

Reducing the cost of putting things into orbit also changes the economics of direct kinetic weapons in space.

That said I think people overestimate how much the US and Russia actually strive to destroy each other militarily.

And in general arms races aren’t a good thing, you build a missile shield your enemy builds a better missile.

What about submarines? Can a LEO missile hit a nuke launched from a submarine off the coast of New York in time to stop it?

Maybe, if you had a string of pearls of LEO missiles orbiting above New York at all times.

But you might as well have land based anti-aircraft nukes, I guess. (Shooting nukes with nukes.)

The potential for ABM systems to actually neutralize their ICBMs is probably why Russia is developing nuclear powered (and armed of course) torpedoes and cruise missiles.

That doesnt make sense for the torpedoes, which aren't a replacement for ICBM/SLBMs. It's plausible for the cruise missiles, which can replace SLBM/ICBMs in the strategic strike role.

I believe the torpedoes are intended as retaliation weapons. In theory they have the range of ICBMs, though can only attack coastal targets and are obviously orders of magnitude slower. They've spent a whole hell of a lot of money on these, including building the world's longest submarine (the K-329 Belgorod, which seems to be an Oscar-II given the stretch limo treatment) to carry these torpedoes. They may also be planning on creating 'silos' for these torpedoes on the floor of the Arctic Ocean.

Submarines can launch nuclear cruise missles that can annihilate a country without requiring that they pass through space.

There are more things in heaven and earth, Horatio..

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