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Old 10-02-2017, 03:49 PM   #10
Phoenix_Dragon
 
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Default Re: [Ultra-Tech] What would naval warfare at TL10 look like?

Quote:
Originally Posted by johndallman View Post
Maneuverable reentry vehicles have been built and successfully tested. The technology is not like other air vehicles, but it works. The US did not adopt them in the early 1980s, but that doesn't prove that they won't be in use at TL10.
That vehicle has already finished reentry by the time it maneuvers, and does those maneuvers at a speed significantly slower than orbital velocity. In fact, it's speed is comparable to the hypersonic missiles I mentioned, but with a high, obvious flight profile. It's also essentially the same idea as the DF-21D I mentioned, which puts the same idea into an anti-ship role.

Coming in at full orbital velocity is going to be a bit more limiting on maneuverability.

Quote:
Originally Posted by Anaraxes View Post
The first point isn't true, nor follows from the second.
It doesn't follow from the second because you misquoted me by clipping off half the statement. Not cool.

You seem to be presenting this scenario as if someone is setting off a bomb nearby a stationary rod, but that's about as far from the scenario as we could get. The rod isn't stationary; it's closing at near-orbital velocity, upping the energy of the impact by roughly 4 to 10 times, depending on when the intercept occurs (The rod is going considerably slower at impact than during reentry) and the angle of impact (Likely to be head-on if we're talking about a ship defending itself). Further, this isn't just a random explosion nearby; this is a kinetic impact directly on the surface of the rod with a significant directional component. With the minimum speed for a head-on intercept, we're talking mach 20-25, close to the velocity that you get from a HEAT jet. This isn't some simple proximity detonation, and it's not distributed randomly (The LEAP is a unitary warhead, not some package of multiple smaller projectiles). It's going to be a single focused impact point leaving a sizable hole or crater on the surface of that reentry vehicle.

Get a solid head-on impact during reentry, and you stand a good chance of blowing the entire head off that rod.

Needless to say, these are things you really don't want during reentry. Hell, you don't want it when hypersonic. It very likely leaves the vehicle uncontrollable during reentry, if not tearing it apart through aerodynamic forces. If it does survive and regain control, it would have burned a great deal of energy, which, combined with impaired aerodynamics from the impact, might easily leave it unable to maneuver onto its target.

But even that isn't the end of it. If it's got terminal self-guidance (And it needs guidance to have any chance of hitting a mobile target 10+ minutes after launch), then it needs to see the target, and that means vulnerable sensors that really don't respond well to mach 20+ impacts.

So yeah, the reason I said it having a kinetic kill warhead didn't provide any benefit here is because it makes no meaningful difference in the outcome. A kinetic intercept at these velocities is devastating, even against another kinetic-kill vehicle.

And yes, you can scale up bigger and bigger until you find something that would survive just through sheer mass, but I was imagining we were talking practical tactical weapons that might be employed against ships. You're obviously not going to stop a moon, but you'll stop reasonable threats. Even the thor project is already getting a bit silly for anything other than strategic mass-bombing and hardened-target strikes against a nation without suitable air/space defense.
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