5 ms·

I remember reading about this a long time ago. I don't really remember the details, but the interesting part of was that China was developing / already develop

I remember reading about this a long time ago. I don't really remember the details, but the interesting part of was that China was developing / already developed space based missiles which reenter the atmosphere at hypersonic speeds to destroy carriers. Apparently many believed that this technology would completely negate the usefulness of aircraft carriers, and severely hamper the US advantage that comes from their lead in this area.

nradov 5y ago
China doesn't have any space based missiles. They have some mobile land based intermediate range ballistic missiles which could potentially be used against aircraft carriers. All ballistic missiles are hypersonic when they re-enter the atmosphere. Those missiles don't negate the usefulness of aircraft carriers because the missiles can only hit a target if they get reasonably precise and timely targeting data. Also carrier escorts carry ABMs which might be able to intercept a limited number of ballistic missiles.
- sudosysgen 5y ago
  The Chinese are going to be putting sensors on these missiles. Aircraft carriers are huge targets that can be detected perhaps even before re-entry by the missile itself. Timely and precise targeting data is unlikely to be necessary.
- donavanm 5y ago
  I suspect the parent is mixing up the other weeks news about the ballistic to orbital to trans continental glide path demonstration that significantly challenges traditional ballistic missile defense due to the orbital & glide path conponents.
- mrjangles 5y ago
  This is a strange comment. It is an aircraft carrier. Any country with a satellite already has extremely precise and permanent targeting data on every one of the US aircraft carriers. anyway: https://direct.mit.edu/isec/article/41/1/7/12133/Future-Warfare-in-the-Western-Pacific-Chinese https://direct.mit.edu/isec/article/41/1/7/12133/Future-Warf...
  - nradov 5y ago
    Aircraft carriers move around quickly. No nation, not even China, has enough reconnaissance satellites to maintain continuous coverage. And the satellites aren't survivable; they will be the first casualties in any major conflict. Targeting data can potentially also be linked from submarines or aircraft, but those are also vulnerable. There are many ways to break the kill chain. That's not to say that carriers are invulnerable; they can probably be knocked out eventually by a peer adversary who is willing to accept heavy losses.
    - sudosysgen 5y ago
      Carriers are very slow compared to missiles. Between the time the missile is launched and impact there will only be around ~6km in radius to the set of points where the carrier coule he. China is making unmanned submarines and aircraft capable of targeting a carrier. It doesn't matter if your drone is shot down, for it to be shot down it's probably already close enough to detect the carrier. Same for a submarine.
- shardinator 5y ago
  Well if you use a simple convolutional neural network and can get within visual range, hitting the target should be trivial.
  - nradov 5y ago
    Huh? I don't know why you think a convolutional neural network would help but that's not how this stuff works. Due to heating effects and clouds there is no "visual range" for a ballistic missile. Any terminal course corrections will be done with radar.
    - sudosysgen 5y ago
      That's incorrect. There is a visual range. You can either image in the UV spectrum, or simply choose your optics so you can image the carrier from before re-entry. Once you've got a position there's nothing the carrier can do in those 30 seconds before impact so you won't hit it, so there is not even a necessity for terminal course correction.
      - nradov 5y ago
        Total science fiction. You're not going to see enough from orbit with the type of optical sensor that can fit on the re-entry vehicle.
        sudosysgen 5y ago
        Actually yes, you can. You can run the numbers if you wish. To see a target that is 300m large from 300km away you need an angular resolution of 1 miliradian which requires a 0.5mm aperture in the visible spectrum. To be able to image it well and tell it apart from something else consistently and obviously you'd have more than you need with a hundred times the resolution which would require a 50mm aperture. In other words, absolutely and completely feasible. You could hold a camera with an 1200mm f/20 Cassegrain lens that could take a picture of a carrier from 300km with a fair amount of detail in your hands, let alone fit it into a 3 ton reentry vehicle.
deleted 5y ago
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nradov 5y ago

China doesn't have any space based missiles. They have some mobile land based intermediate range ballistic missiles which could potentially be used against aircraft carriers. All ballistic missiles are hypersonic when they re-enter the atmosphere. Those missiles don't negate the usefulness of aircraft carriers because the missiles can only hit a target if they get reasonably precise and timely targeting data. Also carrier escorts carry ABMs which might be able to intercept a limited number of ballistic missiles.

sudosysgen 5y ago
The Chinese are going to be putting sensors on these missiles. Aircraft carriers are huge targets that can be detected perhaps even before re-entry by the missile itself. Timely and precise targeting data is unlikely to be necessary.
donavanm 5y ago
I suspect the parent is mixing up the other weeks news about the ballistic to orbital to trans continental glide path demonstration that significantly challenges traditional ballistic missile defense due to the orbital & glide path conponents.
mrjangles 5y ago
This is a strange comment. It is an aircraft carrier. Any country with a satellite already has extremely precise and permanent targeting data on every one of the US aircraft carriers. anyway: https://direct.mit.edu/isec/article/41/1/7/12133/Future-Warfare-in-the-Western-Pacific-Chinese https://direct.mit.edu/isec/article/41/1/7/12133/Future-Warf...
- nradov 5y ago
  Aircraft carriers move around quickly. No nation, not even China, has enough reconnaissance satellites to maintain continuous coverage. And the satellites aren't survivable; they will be the first casualties in any major conflict. Targeting data can potentially also be linked from submarines or aircraft, but those are also vulnerable. There are many ways to break the kill chain. That's not to say that carriers are invulnerable; they can probably be knocked out eventually by a peer adversary who is willing to accept heavy losses.
  - sudosysgen 5y ago
    Carriers are very slow compared to missiles. Between the time the missile is launched and impact there will only be around ~6km in radius to the set of points where the carrier coule he. China is making unmanned submarines and aircraft capable of targeting a carrier. It doesn't matter if your drone is shot down, for it to be shot down it's probably already close enough to detect the carrier. Same for a submarine.
shardinator 5y ago
Well if you use a simple convolutional neural network and can get within visual range, hitting the target should be trivial.
- nradov 5y ago
  Huh? I don't know why you think a convolutional neural network would help but that's not how this stuff works. Due to heating effects and clouds there is no "visual range" for a ballistic missile. Any terminal course corrections will be done with radar.
  - sudosysgen 5y ago
    That's incorrect. There is a visual range. You can either image in the UV spectrum, or simply choose your optics so you can image the carrier from before re-entry. Once you've got a position there's nothing the carrier can do in those 30 seconds before impact so you won't hit it, so there is not even a necessity for terminal course correction.
    - nradov 5y ago
      Total science fiction. You're not going to see enough from orbit with the type of optical sensor that can fit on the re-entry vehicle.
      - sudosysgen 5y ago
        Actually yes, you can. You can run the numbers if you wish. To see a target that is 300m large from 300km away you need an angular resolution of 1 miliradian which requires a 0.5mm aperture in the visible spectrum. To be able to image it well and tell it apart from something else consistently and obviously you'd have more than you need with a hundred times the resolution which would require a 50mm aperture. In other words, absolutely and completely feasible. You could hold a camera with an 1200mm f/20 Cassegrain lens that could take a picture of a carrier from 300km with a fair amount of detail in your hands, let alone fit it into a 3 ton reentry vehicle.

deleted 5y ago

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