SpaceX launches military satellites tuned to track hypersonic missiles | Hacker News Reader

SpaceX launches military satellites tuned to track hypersonic missiles

arstechnica.com

45 pointsRafelMri13 comments

Well, I guess it's some sort of public gesture of false reassurance, since all I have been hearing about these past two years is Russia's hypersonic missiles with plasma shields that cannot be shot down, and China's hypersonic arsenal. I am old enough to remember how Ronald Reagan was roasted about the SDI (Strategic Defense Initiative, or "Star Wars") program aimed to develop space-based systems to protect the United States from nuclear missile attacks. Hey, it mentioned lasers and particle beams, so as a Trekkie I was all ears. It would be interesting to see the fits and starts of that program over the past 40 years. It was renamed the MDA (Missile Defense Agency).

It is the hypersonics which are overhyped. They suffer some severe disadvantages compared to traditional ballistic missiles. Their only real advantage is that since they fly on a very different trajectory, traditional missile tracking systems are not good at detecting them; hence the need for dedicated tracking satellites. Once you can track them, hypersonic weapons are just lower, slower warheads that can not deploy countermeasures.

It is the maneuverability that makes them hard to actually hit, since it is not a simple parabolic or dumb ballistic missile trajectory, even if the ICBM or SRBM is going Mach 5, or hypersonic. That's why they usually don't include ICBMs and SRBMs in the 'hypersonic' category. A military arsenal needs to be diverse and hypersonic missiles have their uses for sure.

The maneuverability actually doesn't make them harder to hit, they are still far less maneuverable than the interceptors, and critically they can't make course alterations en route based on sensor data to avoid an interceptor. Also, most ballistic missiles don't actually fly in dumb, parabolic arcs, they have some limited maneuvering capability. Really there are two categories of hypersonics - hypersonic cruise missiles (HCM) and hypersonic glide vehicles (HGV). HGV's are very comparable to ICBMs, it's really just the trajectory that's different, staying within the atmosphere. HCMs are dramatically slower but they actually have some genuine maneuverability and are more in the regime of aircraft SAM defenses than ballistic missile defense. It's the HGVs that these satellites are meant to counter. The issue is that interceptors need some time to launch and close the distance, and by the time a traditional missile warning system detects a relatively low flying hypersonic weapon, it's practically at the target. With in flight tracking by satellite, you can engage hypersonics at similar distances to traditional ballistic missiles.

Hypersonics really only are useful for getting past a missile defense system set up to counter traditional ballistic missiles. If your adversaries don't have such systems, or if those systems can be defeated by other, cheaper means, or if they are hypersonic defense capable, then there isn't much argument for hypersonics. Certainly it's good to have options, but assuming your military budget is finite, spending those dollars just about anywhere else will be more beneficial.

What's the "false reassurance" in this? It isn't the SDI, and plus, times have changed since then, launching and maintaining a constellation of a few hundred satellites communicating over radio and inter-satellite lasers is realistic now, that part is already in commercial use. They also aren't talking about space based interceptors.

Tracking hypersonics from orbit is relatively straightforward, they get hot enough to produce plasma, and thus will be very obvious in infrared. The challenge isn't tracking, it's reacting fast enough to the information.

I meant to convey that the headline, "SpaceX launches military satellites tuned to track hypersonic missiles" makes it sound like we will have military satellites in position to counter Russian/Chinese/?'s hypersonic missiles, but this is in the deployment, pre-testing phase, so I am intimating it may seem to relieve the scare that has been in the media about hypersonic missiles, but it is 'false reassurance' because it is not a proven system. The headline would better read: "SpaceX launches military satellites tuned to track hypersonic missiles for testing", or something to that effect. Hypersonic missiles fly low and fast and are highly maneuverable, and given one hasn't been verified as shot down to date (I wouldn't include Ukraine's press release of shooting down 6 Russian Kinzhal missiles), should lend some skepticism about how effective we would be in countering them. Even Israel's Iron Dome lets missiles through and those are old tech. I agree with your last line, although tracking is one thing. Predicting trajectory is another, and hypersonics are maneuverable enough to thwart predictive trajectory intercepts.

The question when something like this comes out so clearly is why is this information being released? Internal or external politics, bluff or threat… etc.

The whole paradigm of deterrence is avoiding war by convincing your opponents that attacking you will be futile, or at least excessively costly. What good would a deterrent be if people didn't know you had it? Obviously you're not going to give away enough technical detail to help a would be adversary to defeat the system, but announcing the general existence of such a system is routine.

If your adversary knows your capabilities, even vague details, they can usually extrapolate the specifics close enough to defeat them, physics is like that. Also if you know your adversary has a capability you’re very likely to try to replicate it.

Like this announcement is probably a response to the public discourse by the US of Russian antisatellite space nukes which they are developing and denying.

It could be a negotiation tactic (we’ll not develop this if you don’t develop that), a threat (we’ll develop this faster if you don’t stop), or internal politics (we’re doing stuff that will be potent against Russia too) or many other things.

The adversary not knowing at all what you have and having to imagine your capabilities can be a bigger deterrent. But it’s a big game with many players and you have to weigh the many advantages and disadvantages of each action.

The thing is though, a hypersonic can't really hide the massive hest signature it generates. To defeat that you'd just end up with an entirely different kind of missile (either having the missile go up into space, at which point it's an ICBM, or having it go slower, which turns it back into a regular cruise missile). So either way, the system specifically stated as tracking hypersonics, has technically not been defeated at its job.

> If your adversary knows your capabilities, even vague details, they can usually extrapolate the specifics close enough to defeat them, physics is like that.

This is not generally true. Further, the existence of satellites can't be readily hidden, anyone with a telescope can see that they are up there.

> Also if you know your adversary has a capability you’re very likely to try to replicate it.

It's not a problem if other nations replicate this capability. Indeed it would likely be good for the US if they did - the more confident a country is in their defenses the less they need to rely on pre-emptive offense. It's also worth noting that the US generally lags behind in hypersonic weapons as they're not really useful to US strategy, so adversaries pursuing anti-hypersonic capabilities would really just be wasting resources.

> Like this announcement is probably a response to the public discourse by the US of Russian antisatellite space nukes which they are developing and denying.

Definitely not. For starters this program has been in the works for years, and the launch was scheduled months ago. Further, it seems a little silly to advertise that you're pouring resources into satellites right after disclosing that your adversary is working on a weapon to destroy satellites.

> The adversary not knowing at all what you have and having to imagine your capabilities can be a bigger deterrent.

If you are confident they will overestimate your capabilities.

> It could be a negotiation tactic (we’ll not develop this if you don’t develop that), a threat (we’ll develop this faster if you don’t stop), or internal politics (we’re doing stuff that will be potent against Russia too) or many other things.

Or it could be a routine announcement as is typical for missile defense systems. Sure there could be some ulterior motive, but there is absolutely no reason to believe that to be the case.

This is more defensive in nature, I guess flexing your defensive capabilities is less revealing than flexing offensive capabilities.

It's probably real (I'm not sure why they'd lie about it), but the exact capabilities are classified. The problem is, there's not currently enough satellites deployed to get the full monitoring and communication needed for a space-based SDI implementation, so it's more of a demonstration. No interceptors either, who knows if that will ever happen.

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