Comment by ckozlowski | Hacker News Reader

Comment by ckozlowski | Hacker News Reader

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Can it not? I'd reverse the question: Can China find it?

That's the part that I find missing from these discussions. Missiles like the D21 sound really deadly, but the information and communications needed to successfully target a carrier hundreds or thousands of miles away and deliver the weapon successfully is the much more difficult part of the equation. As the U.S. Navy (paraphrasing) said themselves, "The D21 has a long kill chain, and plenty of places to disrupt that kill-chain."

Likewise, the carrier goes around with much more than it's planes and escorts. It has the information being fed to it from ISR elsewhere, from satellites overhead to pre-mission information, communications eavesdropping, etc to know what they're up against and when and where they might encounter it. That, in my opinion is far more important than the specifics and specs of such and such weapon.

The success or defeat of a carrier battle group I think is going to depend far more on who knows what and when, and therefor, what's going on in the electromagnetic spectrum, than any singular missile.

'Can it not? I'd reverse the question: Can China find it?'

You can find it yourself on free satellite imagery collected by the european sentinel satellites, provided globally free of charge. All ships are really easy to see from space, especially giant carriers.

Ofcourse sentinel takes images once every few days, and how that compares to spy satellites and how you target a missile from there i dunno

Ships move around. Those satellites don't provide the real-time target tracks needed by ballistic missiles. Reconnaissance satellites are themselves no longer survivable.

Spot on. To add to this, the Navy knows those satellite tracks. It's one thing to spot a carrier in port from a days old image. It's another to find it actively evading you in wartime.

And regarding the satellites themselves, also agreed. I really believe that success at sea is going to depend a large part on success in space, and many countries know it.

What possible action can a carrier take to evade satellite that can take daily photographs? Its not a plane, it cant travel a thousand kilometers in a day. It can only be withing a limited radius of it's initial position

I would expect that every major nation keeps track of every carrier on a daily basis

Precision targeting of hypersonic ballistic projectiles is very difficult. While landing ballistic missile within 100 miles of a carrier is trivial, direct hits with conventional weapons require high precision measurements of carrier velocity, and position. The inbound weapon has very little time to correct its trajectory, and few sensors which will be effective at hypersonic velocity at the ranges required.

It's like finding a needle in a haystack. Find an extremely tiny object (relatively speaking) in millions of square miles of ocean.

A carrier is fast. 30+ knot speed, likely more (top speed is classified.) Going with 30 knots gives you 720 nautical mile radius of action, or 2,156,746 square miles.

This is to say nothing of the satellite's capabilities, or the back-end systems needed to find objects in the photographs.

There's better ways to go about it though, and the open source satellites taking photos are probably the worst for this job, to be brutally honest. But some examples:

The Soviets use to fly radar satellites to search for US carrier groups. https://en.wikipedia.org/wiki/US-A

The Chinese are suspected to have their own satellites for this purpose, though they are passive in nature, searching for electromagnetic emissions from the ships: https://en.wikipedia.org/wiki/Yaogan (Look up EMCON on how this is countered.)

But in short, it yes a carrier can still hide, though it's tricky. And this is without active measures being taken. And the Carrier Group Commander will have intelligence notifying them of when the overhead passes are. With that, they can start piecing together what the kill chain looks like, from getting that data down to the ground, the time it takes their analysts to find the carrier in it, get that data to command, and then down to the assets to take action against it, plan a sortie, and get the weapon out to where it is...during all that time of which the carrier is free to maneuver and take other counter measures. It becomes a game of cat and mouse.

It's rather dated now, but the classic book "Red Storm Rising" illustrates some of this and how it plays out.

The carrier strike group commander also has some limited capability to shoot down satellites in LEO.

A carrier can travel ~700 nautical miles in a day, which would be around the width of Texas. That is not a small area to search, ~1,539,380 SNM. Obviously you could narrow it down based on where you think the group is travelling to, etc, but if they are trying to not be found, day old data puts you in a tough position.

Also, China has it's own spy satellites. They're supposedly about equal to US versions in capabilities, China just doesn't have nearly as many of them.

You can destroy carriers even without sattelites and firing rockets from far away.

Small fast vessels can be used to search for the carrier and they can fire missiles.

Also, carriers have to be at a certain distance from the shore to mount an attack from them. Once they are close to the shore I'd say they are easy to spot.

A carrier in the middle of the ocean is harder to find and destroy, but it can't be used for attacking, and that's what a defending nation needs: enough deterring power to keep the carrier far from its shore.

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