Sub-sonic AShMs

Wombat000

Active Member
Hi,
Just wondering what the consensus is on whether sub-sonic anti-ship missiles can really cut it anymore?
Obviously, against a lesser defended ship the missile has probably has the edge, but what about a peer defended target?
I presume there's no similar thread already, I couldn't see one.
Cheers
 

Todjaeger

Potstirrer
Hi,
Just wondering what the consensus is on whether sub-sonic anti-ship missiles can really cut it anymore?
Obviously, against a lesser defended ship the missile has probably has the edge, but what about a peer defended target?
I presume there's no similar thread already, I couldn't see one.
Cheers
Given that the US has been developing the LRASM, which is an AShM variant of the LO, subsonic JASSM and has recently selected the subsonic NSM as the OTH AShM aboard LCS, that would seem to suggest subsonic missiles remain the 'way to go' at least for the time being. If/when hypersonic AShM become effective, then subsonic sea-skimming AShM might start getting replaced.

Supersonic AShM are not a new concept, but in order for the missiles to achieve such capability, it causes trade offs in other areas, specifically the thermal signature. That increase in the thermal signature adds another way, and therefore opportunity for a supersonic AShM to be detected, when compared with 'normal' subsonic sea-skimming AShM which can be blocked by the curvature of the earth, or lost in the radar clutter getting reflected by from waves. When factoring in the LO shaping and treatments to further reduce the already small signature of a missile, it would seem that subsonic is a more overall capable way to go.
 

Boagrius

Well-Known Member
I imagine subsonic AShMs also offer a certain amount of flexibility in terms of routing, man-in-loop guidance (thinking of Tomahawk here), and coordinating the arrival time of multiple weapons over the radar horizon of the target and/or its escorts. I also wonder how they compare to super/hypersonic weapons in terms of cost, all else being equal. The US, for example, has the potential to repeatedly deliver enormous volleys of syncronised subsonic AShMs via its vast tactical and (especially) strategic aviation fleets. For example a single B1 can apparently carry 24(!) LRASMs. That is a disgustingly large number of stealthy cruise missiles on a single aircraft.

I suspect quantity has a quality all of its own when it comes to saturating point defences...
 
Last edited:

Todjaeger

Potstirrer
I imagine subsonic AShMs also offer a certain amount of flexibility in terms of routing, man-in-loop guidance (thinking of Tomahawk here), and coordinating the arrival time of multiple weapons over the radar horizon of the target and/or its escorts. I also wonder how they compare to super/hypersonic weapons in terms of cost, all else being equal. The US, for example, has the potential to repeatedly deliver enormous volleys of syncronised subsonic AShMs via its vast tactical and (especially) strategic aviation fleets. For example a single B1 can apparently carry 24(!) LRASMs. That is a disgustingly large number of stealthy cruise missiles on a single aircraft.

I suspect quantity has a quality all of its own when it comes to saturating point defences...
Evaluating the costs of modern supersonic vs. high subsonic AShM IMO would not be difficult, but I do not believe that it would be particularly informative.

The modern supersonic AShM tends to be of Indian or Russian manufacture which tends to cost less than US/European manufacturing. With the US/Europe, and then mainland China being principally users of high subsonic AShM, one could look at export contracts to try and figure out a per missile cost for both sub and supersonic AShM, that might only provide cost information.

It would not really provide any information on which missile was more effective, and it also would not include the costs or supporting elements of the battlesystems used to achieve an effect with the AShM.

For instance, there would need to be an MPA and/or ISR asset to detect the potential targets for the missile strike and have that asset either launch the strike, or cue other assets to launch and a datalink to relay targeting info.

Given the size of most of the supersonic AShM, it appears that it would take a large number of launching platforms to achieve a significant number of inbounds. Looking at what the Soviet maritime strike doctrine from the 1980's had been, this was to be achieved by regiments of Backfires launching against a USN CBG. At this point, there are only a handful of nations which might be able to operate that number of aircraft at once, never mind directing that many against a single target or task force.
 

Blackshoe

Defense Professional
Verified Defense Pro
Given that the US has been developing the LRASM, which is an AShM variant of the LO, subsonic JASSM and has recently selected the subsonic NSM as the OTH AShM aboard LCS, that would seem to suggest subsonic missiles remain the 'way to go' at least for the time being. If/when hypersonic AShM become effective, then subsonic sea-skimming AShM might start getting replaced.

Supersonic AShM are not a new concept, but in order for the missiles to achieve such capability, it causes trade offs in other areas, specifically the thermal signature. That increase in the thermal signature adds another way, and therefore opportunity for a supersonic AShM to be detected, when compared with 'normal' subsonic sea-skimming AShM which can be blocked by the curvature of the earth, or lost in the radar clutter getting reflected by from waves. When factoring in the LO shaping and treatments to further reduce the already small signature of a missile, it would seem that subsonic is a more overall capable way to go.
I'd add that supersonics tend to be much larger, as well, and that has some drawbacks namely in that it limits the kind of platforms you can deploy it from.

Also, as you note, it's hard to make supers with small RCS. "Fast" isn't that helpful in and of itself, when you can still see the missile coming a long way off.
 

Feanor

Super Moderator
Staff member
Evaluating the costs of modern supersonic vs. high subsonic AShM IMO would not be difficult, but I do not believe that it would be particularly informative.

The modern supersonic AShM tends to be of Indian or Russian manufacture which tends to cost less than US/European manufacturing. With the US/Europe, and then mainland China being principally users of high subsonic AShM, one could look at export contracts to try and figure out a per missile cost for both sub and supersonic AShM, that might only provide cost information.

It would not really provide any information on which missile was more effective, and it also would not include the costs or supporting elements of the battlesystems used to achieve an effect with the AShM.

For instance, there would need to be an MPA and/or ISR asset to detect the potential targets for the missile strike and have that asset either launch the strike, or cue other assets to launch and a datalink to relay targeting info.

Given the size of most of the supersonic AShM, it appears that it would take a large number of launching platforms to achieve a significant number of inbounds. Looking at what the Soviet maritime strike doctrine from the 1980's had been, this was to be achieved by regiments of Backfires launching against a USN CBG. At this point, there are only a handful of nations which might be able to operate that number of aircraft at once, never mind directing that many against a single target or task force.
Conversely a smaller number of ships/subs might do the trick if the Nakhimov refit is any indicator. Now I don't think Russia will operate more then 2 (3 at the outside) of them, but the new Chinese Type 55 are likely to be more numerous. They could certainly produce the necessary number of inbounds, especially if they're supported by smaller vessels. A potential PLAN taskforce of 1 Type 55, and several Type 52s, with air support, could deliver Cold War levels of supersonic inbounds. Even the future VMF should be able to cobble together a Kirov + 1155Ms/22350s, with an 885 sub to support.
 

Wombat000

Active Member
  • Thread Starter Thread Starter
  • #7
Thank you all for taking the time to reply to this.
There is some perceived skepticism (that I've heard) of the combat value of sub-sonic SSMs.
I admit prior to the feedback I was dubious of them too, now perhaps not so much?

Sorry for my slow reply, I didn't want the issue to prematurely shut down.

Cheers to all.
 

CroNkWatcher95

New Member
Sub-sonic AShM are generaly powered by turbojet and turbofans which means electricity generated from those makes large batteries unnecessary which power ones that have liquid fuel rocket propulsion or are solid fueled which are generaly super-sonic though there were ones that were liquid fuel rockets or turbojet powered then there is also ramjets.

Thus sub-sonics with turbojet/turbofan are smaller lighter for same range and warhead payload, have lower radar cross section, lower heat/infrared signature, fly lower and are overall less costly thus more can be made thus you can equip more ships and coastal defense armor to fire more missiles to overwhelm A-ASh defenses.
 
Top