Does the US not have a supersonic SSM?

[Pillar]

I've never heard of anything in the US inventory by way of a supersonic anti-ship surface to surface missile. The Indian navy has some SSMs which are said to do supersonic maneuvers on the last phase of their attack. Are American ships presently limited to subsonic anti-ship missiles?

[ekempey]

The only thing I know that they have is the SM2. From Wikipedia:
"The Standard can also be used against ships, either at line-of-sight range using its semi-active homing mode, or over the horizon using inertial guidance and terminal infrared homing."
http://en.wikipedia.org/wiki/RIM-66_Standard

[Molon Labe]

SeaSparrow has ASUW capability as well, and my guess would be that NLOS/Netfires is supersonic for at least part of its flight; but, yes, we don't have any dedicated surface launched supersonic antiship missiles.

[Pillar]

Unbelievable! 62kg of blast fragmentation is not trivial but I'm really quite surprised that India has a more capable surface-to-surface attack capability than the USN's latest and greatest.

[Molon Labe]

The USN hasn't deployed a new antiship SSM since 1984. India is developing a brand new one right now. So yeah, they're ahead right now. We'll have the Harpoon Block III in 2011 if all goes as planned, which will certainly have updated guidance capabilities for improved flexibility and lethality (and hopefully will combine a backup sensor with the radar for terminal homing--not something that's been announced as of today, but something they'll probably need in light of the incident with the Saar 5 vs. C-802).

Speed isn't all there is to capability though. Subsonic seaskimmers have proven quite effective, in conflicts from 1967 to 2006 (and a subsonic non-seaskimming SS-N-9 in 2008). I'm only aware of one instance where an ASCM was shot down (and it wasn't a seaskimmer) which is the key vunlerablility of a slower-moving missile. Supersonic weapons are about as vunlerable to soft kills, which has so far been the most successful defense.

[MBot]

Originally Posted by Molon Labe

Supersonic weapons are about as vunlerable to soft kills, which has so far been the most successful defense.

True, but supersonic missiles also reduce the time available to deploy counter measures in the first place.

[Molon Labe]

I don't want to claim to be an EW expert, but I think you still have enough warning to turn the jammers on, pop chaff, etc. I agree that the time factor will make them more effective in this regard, but I don't think it has a huge impact.

One thing to consider is the flight profile of most supersonic missiles. They're gas hogs, so if they're going to have any range, they have to fly at high altitude. Older missiles like the Kitchen are high divers; they stay up high until they're terminal. AEGIS or other modern SAM systems can deal with those rather easily today. More modern supersonic missiles (including the Brahmos) use a high-low profile, where the missile cruises at high altitude until the radar finds the target. It then dives for the surface, gets below the radar horizon and closes the distance to the target until contact is reestablished and it goes terminal. This profile allows for counterdetection by radar and ESM when the missile first searches for the target, which means they know they have to switch their jammers on, orient their ship to the missile to maximize ECM effectiveness, and start puking chaff. Also, by being larger and faster, they are easier to detect on radar.

FWIW, I can't wait for the RATTLRS, but right now subsonic seaskimmers have a proven track record of success, while their larger supersonic cousins have yet to be used in combat (at least in an antiship role).

[Pillar]

Interesting stuff. I think (disclaimer - I'm going by simulations and technical data) the NATO ships should have no trouble shooting down volleys of subsonic sea skimmers. But many of the Warsaw (and export variants) ships as well as stuff like the OHP are vulnerable to volleys of subsonic missiles. Basically, AEGIS changed the game by being able to ward off swarms of slow missiles indefinitely (as ammo allowed, which exceeds attacker SSM loadouts anyhow.) The supersonic missiles can get through that system using volley fire tactics again. The point therefore is not to beat the helmsman to the countermeasures control panel by going supersonic, but to increase the number of missiles the AEGIS system needs to deal with simultaneously within a given amount of time. The fact that each incoming missile is now much harder to hit (shorter time for engagement, including a much tighter lethal window for SAMs); -- So the dash has been to re-equip all the cruisers and missile boats on that side with supersonic missiles, and the program India is doing seems to be about getting VLS and supersonic terminal homing married. They already "upgunned" the missile boats with supersonic sea skimmers afaik. NATO simply hasn't had to worry about it because they are the only ones fielding AEGIS. Is that correct?

[Pillar]

Originally Posted by ekempey

The only thing I know that they have is the SM2.

Originally Posted by Molon Labe

SeaSparrow has ASUW capability as well, and my guess would be that NLOS/Netfires is supersonic for at least part of its flight; but, yes, we don't have any dedicated surface launched supersonic antiship missiles.

"Operational range 40 to 90 nautical miles" (from the Wiki)

Yeah this is what I was looking for. Thanks.

[Molon Labe]

SM-2 and SeaSparrow are SARH missiles, so their range is limited by the horizon. 40-90nm is against aircraft, not ships.

[Pillar]

Yeah I was just thinking about the motor running out and a heck of a lot of that range being glide... so no, this isn't a good anti-ship missile. The motor burn range and then a little bit of cruise after that probably aren't far at all. The radar problem might be solved by a helicopter - ? I'm not sure they have the capability to do third party guidance for missiles like that. At glide-phase ranges they probably wouldn't be harder to shoot down than a harpoon, maybe easier, in fact.

[Molon Labe]

Originally Posted by Pillar

Yeah I was just thinking about the motor running out and a heck of a lot of that range being glide... so no, this isn't a good anti-ship missile. The motor burn range and then a little bit of cruise after that probably aren't far at all. The radar problem might be solved by a helicopter - ? I'm not sure they have the capability to do third party guidance for missiles like that. At glide-phase ranges they probably wouldn't be harder to shoot down than a harpoon, maybe easier, in fact.

I'm quite positive that they don't have that capability. The SM-6 will have AMRAAM-style datalink guidance followed by autonomous capability, so it's possible in theory that a 3rd party platform could provide the link information, but the SM-2 and SeaSparrow absolutely do not have that capability or anything like it.

[Pillar]

Anything about the volley vs aegis post?

[Molon Labe]

Originally Posted by Pillar

Interesting stuff. I think (disclaimer - I'm going by simulations and technical data) the NATO ships should have no trouble shooting down volleys of subsonic sea skimmers. But many of the Warsaw (and export variants) ships as well as stuff like the OHP are vulnerable to volleys of subsonic missiles. Basically, AEGIS changed the game by being able to ward off swarms of slow missiles indefinitely (as ammo allowed, which exceeds attacker SSM loadouts anyhow.)

Slow or fast. AEGIS was designed with Mach 3 missiles like the Kitchen in mind.

The supersonic missiles can get through that system using volley fire tactics again. The point therefore is not to beat the helmsman to the countermeasures control panel by going supersonic, but to increase the number of missiles the AEGIS system needs to deal with simultaneously within a given amount of time.

If you fire two missiles two seconds apart, they arrive two seconds apart, whether those missiles are going 500kts or 2000kts. Speed doesn't force the system to deal with any more missiles. What it does it gives it less time to deal with each missile; this is true whether you fire 1 or fire 100.

Beating missile defenses today is all about reaction time. The less time the boat has to detect, classify, and react, the more likely you're going to get a hit.

The fact that each incoming missile is now much harder to hit (shorter time for engagement, including a much tighter lethal window for SAMs); -- So the dash has been to re-equip all the cruisers and missile boats on that side with supersonic missiles, and the program India is doing seems to be about getting VLS and supersonic terminal homing married. They already "upgunned" the missile boats with supersonic sea skimmers afaik. NATO simply hasn't had to worry about it because they are the only ones fielding AEGIS. Is that correct?

The early trend with the Soviets was to build faster missiles, but that trend has since turned to lower-altitude missiles (SS-N-22, -25, -27)

As for the NATO side, the SA-N-6 and -9 systems, like AEGIS, use phased array radars tied to high-performance VLS missiles. US, and probably the rest of NATO as well, has simply not cared about ASUW as a priority since the Cold War ended. It's all about strike warfare now that the Russian fleet is rusting away in port and only leaves with a salvage tug as part of the formation. Even the RATTLRS is primarily being sold as a strike weapon that's more likely to reach the target before the targets change location.

[Pillar]

Interesting stuff, thanks. I asked a similar question (in more general terms) on another forum and the advice was that main advantage of dealing with slower vs faster inbounds was shot allocation, i.e, getting to wait and see the results of your shots before deciding to shoot again or retain the missile for other use. That is reduced to expected defensive use as far as I know with frigates, because they use dedicated missile systems for each purpose. A friend actually wrote out a simulator in Mathematica and passed along the findings. I can dig up a link for that if you're interested in the analysis. I'm curious how significant (or not) the difference in kill probability for defensive missiles is against supersonic vs subsonic sea-skimmer missiles?