Issues on Intercepting Hypersonic Missile.

[crobato]

I don't know why you keep forcing the 4+ missile against target issue. In the first place, the standard protocol is to fire two missiles at the target, and only after both will miss, then another two will be fired at the target. You need to reserve you missiles against _all_ incoming targets and you don't waste them throwing too much at a single target until they are confirmed to have hit or missed.

 

[Roger604]

If you detect the missile far enough out, then you have enough time to fire a second salvo if the first fails. But in the case of a sea-skimmer, you may not detect it until it turns on its active radar on terminal approach. At that point in time, you have about a minute.

Since it takes time to launch standards or ESSM -- you need to be certain you detected something, clear the deck nearby the launchers, open the doors, vent the exhaust, let the missile rise, and then the missile has to tip over, and quickly streak away to the target, hopefully destroying it -- the whole process may take about 20 seconds.

So for a sea-skimmer you have one shot, and need to fire enough missiles that you are highly confident of a kill.

 

[Pointblank]

If you detect the missile far enough out, then you have enough time to fire a second salvo if the first fails. But in the case of a sea-skimmer, you may not detect it until it turns on its active radar on terminal approach. At that point in time, you have about a minute.

Since it takes time to launch standards or ESSM -- you need to be certain you detected something, clear the deck nearby the launchers, open the doors, vent the exhaust, let the missile rise, and then the missile has to tip over -- the whole process may take about 20 seconds.

So for a sea-skimmer you have one shot, and need to fire enough missiles that you are highly confident of a kill.

You are of course assuming that a launch platform would be able to get close enough to launch and that the missile could lock on facing very heavy ECM...

 

[crobato]

If you detect the missile far enough out, then you have enough time to fire a second salvo if the first fails. But in the case of a sea-skimmer, you may not detect it until it turns on its active radar on terminal approach. At that point in time, you have about a minute.

Which is more than enough time.

Since it takes time to launch standards or ESSM -- you need to be certain you detected something, clear the deck nearby the launchers, open the doors, vent the exhaust, let the missile rise, and then the missile has to tip over, and quickly streak away to the target, hopefully destroying it -- the whole process may take about 20 seconds.

I'm not sure if it takes that long.

So for a sea-skimmer you have one shot, and need to fire enough missiles that you are highly confident of a kill.

Usually two are. In theory, to play fair, you assume that an interceptor has a 50-50 chance of making a kill or missing. Assuming this in paper, you don't need to 5 missiles on a single AshM when a two missile launch will have at least a 75%. Any missile thereafter added faces diminishing returns, and it is preferable to save the big ones for other AshMs that are incoming. In that case, if the target still manages to escape both missiles, then it will be the job of the secondary defenses (ESSM) and the final line of defenses, (gun based CIWS).

 

[montyp165]

The ANS was a good Harpoon/Exocet sized seaskimming supersonic anti-ship missile being developed by the French and Germans back in the 80's before the program was cancelled. Why not restart something like that, could have the best of both faster engagement times and reduced vulnerability to interception.

 

[Roger604]

Usually two are. In theory, to play fair, you assume that an interceptor has a 50-50 chance of making a kill or missing. Assuming this in paper, you don't need to 5 missiles on a single AshM when a two missile launch will have at least a 75%. Any missile thereafter added faces diminishing returns, and it is preferable to save the big ones for other AshMs that are incoming. In that case, if the target still manages to escape both missiles, then it will be the job of the secondary defenses (ESSM) and the final line of defenses, (gun based CIWS).

A 75% kill rate from an initial salvo of 2 missiles will mean that defending ship is in serious trouble. There would be maybe 30 seconds left before impact and it would be difficult for ESSM to intercept with such little time. A Phalanx or a SeaRAM would be really the last ditch defend.

So if a salvo of 12 missiles are fired at a defending ship, 3 will slip through the initial defense, and if all 3 are not successfully engaged, the ship is in serious trouble.

 

[Jeff Head]

Which is more than enough time.



I'm not sure if it takes that long.



Usually two are. In theory, to play fair, you assume that an interceptor has a 50-50 chance of making a kill or missing. Assuming this in paper, you don't need to 5 missiles on a single AshM when a two missile launch will have at least a 75%. Any missile thereafter added faces diminishing returns, and it is preferable to save the big ones for other AshMs that are incoming. In that case, if the target still manages to escape both missiles, then it will be the job of the secondary defenses (ESSM) and the final line of defenses, (gun based CIWS).

RAM has a pretty phenominal interception rate in exercises. You are seeing them more and more on all major combatants. The carriers all have them now, as do the large deck amphibs down to the San Antonios and others.

Excellent CIWS out to short range. So, for the capitol ships, when you take into account Standard, ESSM, RAM and Phalanyx, you have a very, very good coverage.

 

[crobato]

A 75% kill rate from an initial salvo of 2 missiles will mean that defending ship is in serious trouble. There would be maybe 30 seconds left before impact and it would be difficult for ESSM to intercept with such little time. A Phalanx or a SeaRAM would be really the last ditch defend.

So if a salvo of 12 missiles are fired at a defending ship, 3 will slip through the initial defense, and if all 3 are not successfully engaged, the ship is in serious trouble.

Assuming the 50% kill rate, that still means the probability that 9 out of 12 missiles will be killed by Standards using duo ripple fires. That leaves the other three to be dealt by ESSM, RAM or Phalanx. One also has to assume that some of the AshMs might be decoyed away as well, and a percentage of missiles may succumb to failures.

 

[Roger604]

Assuming the 50% kill rate, that still means the probability that 9 out of 12 missiles will be killed by Standards using duo ripple fires. That leaves the other four to be dealt by ESSM, RAM or Phalanx. One also has to assume that some of the AshMs might be decoyed away as well, and a percentage of missiles may succumb to failures.

Those odds are clearly in favor of the attacker. A ship that is relying on its point defenses like SeaRAM or Phalanx is in deep trouble already. If 10 or more missiles get through within 10 km of the ship, that ship is going down.

RAM has a pretty phenominal interception rate in exercises. You are seeing them more and more on all major combatants. The carriers all have them now, as do the large deck amphibs down to the San Antonios and others.

Excellent CIWS out to short range. So, for the capitol ships, when you take into account Standard, ESSM, RAM and Phalanyx, you have a very, very good coverage.

Actually, standards and ESSM simply can't handle a saturation attack of more than 6 to 10 missiles. Even the SeaRAM has only ~90% chance of interception.

So against a single AEGIS ship, an attacker need only launch about 20 anti-ship missiles to successfully hit it. In a hypothetical scenario with China, 20 missiles can be carried by about 4 H-6K's.

The odds are clearly with the attacking side -- as long as the attackers are able to coordinate a simultaneous attack by many missiles (this is where advanced C4ISR and AWACS become absolutely imperative) -- an AEGIS destroyer is no big deal. It will be defeated.

 

[Jeff Head]

an AEGIS destroyer is no big deal. It will be defeated.

Keep telling yourself that. I am sure you believe it.

Lucky for the PLAN, and other nations, they know better, and understand that a single AEGIS destroyer or cruiser is not going to be attacked, clinically, out on its own. It will be in the company of other assets that will make what you are talking about, both physically, electronically, and logistically much much harder than you presume or set forth, with little chance for success unless so much resource is thrown at it to make the cost benefit analysis almost always favor the defender.

And if a situation arose where that analysis determined that they go for it, there is not a sure success, and they then have to deal with the aftermath in any case.