subsonic vs. supersonic missiles

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19 years 1 month

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Why cant you have stealth and speed ?
It would be an expensive system to reduce LO yet be supersonic.

Isnt F-22 stealth and speed , compared to F-117 which is subsonic and stealth ?

Is there any law of physics which prevents to have both stealth and speed ?


A combination of factors. It's possible to make a supersonic missile stealthy, but much more difficult, & more expensive. It's particularly difficult to reduce the IR signature. Then, there's the matter of physical size. Compare supersonic missiles with subsonic missiles carrying similar size warheads over similar ranges, & you immediately see that the supersonic missiles are much bigger. Bigger is harder to hide.

Bigger also has the disadvantage that you can carry far fewer of them. Each one can be more destructive, if it hits (kinetic energy), but for the same resources, you can launch a fraction of the number. In the anti-shipping role, big supersonic missiles are really meant for attacking big, high-value ships.

It is worth mentioning that high speed does mitigate the targetting problem that has been mentioned here a bit. Note how most supersonic ASMs are quite long ranged, with the longest range (Granit) being among them, as well as the early withdrawal of the US TASM due to targetting concerns IIRC. Having mentioned the TASM, look at its quoted maximum range compared to what this airframe is physically capable of (refer to the TLAM for that) to get an idea of how extensive the search pattern needs to be on a subsonic missile at long range!

The straight line end-game approach many are attributing to supersonics is a bit of a misnomer as well - last time I checked, the Moskit and Yakhont/Brahmos are credited with 15g maneuverability!

As I said above, it is no coincident that the suppliers of these "amazing" supersonics still produce sea-skimming subsonic missiles...

Horses for courses. Helos and aircraft will find it difficult - if not impossible - to handle a Brahmos-class missile, but that doesn't mean such a weapon is useless altogether, other platforms (like large surface ships) will have no issues.

What you're saying is that the PzH2000 artillery piece is irrelevant because Germany also builds the G36 assault rifle :rolleyes:

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15 years

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For a supersonic / hypersonic cruise missile, stealth is irrelevant. Its immense advantage is speed.

http://www.noahshachtman.com/images/RATTLRS%20art.JPG
http://www.kitsune.addr.com/Rifts/Rifts-Equipment/Fasthwkb.jpg

A missile like the projected Fasthawk can reach speeds up to Mach 7, enabling it to penetrate enemy missile defenses like the S-300 family, and accumulating over 30 times the kinetic energy of a subsonic cruise missile, thereby enabling it to penetrate heavily fortified bunkers, reach time-sensitive targets and sink enemy ships the size of supertankers with ease.

http://www.fas.org/man/dod-101/sys/smart/hystrike_view.gif

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19 years 2 months

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some points from my side:

imho the most important point defending against supersonic low flying ashm is to know your enemy and to adapt your fighting doctrine. if a supersonic ashm pops over the radar horizon it is to late to go through a long decision-making. you need a fully automated combat managment system which starts all the active/passive defences for you (or at least with minimal human interaction). the cms should be rule based to allow adaptions to the scenario and to ensure the useability in a high number of contact environment (friends, neutrals and foes)
of course this also requires modern sensors and weapons but they are on the market (apar, sampson, empar, ... ; aster, ram, essm, ....)

stealth of course is influenced by things like airframe material, size and form (flying mach 2.x at sea level heats your airframe up a lot so you need other materials and forms than a subsonic ashm. afaik they used a lot of composite material for the nsm). but becoming "stealth" does also mean to fly extremly low (less than 3m for example) to make the detection and defensive operations even harder (sea clutter etc.). i know that there are a lot of different numbers around about the flight level of ashm but over all i thing it's save to say that a subsonic ashm can fly some meters lower than a supersonic can.

last but not least even a very small ashm with a very low rcs doesn't make to much sense if the ashm-seeker is knocking at the ships esm-door. imho this point is often underestimated because afaik in most cases the first signes of an incoming ashm was not a radar track but an esm contact. (with my fully automated and integrated cms the esm will at once start a cued radar and ir/eo search to get a track and to evaluate the threat, start jamming, decoying etc.)

subsonic vs. supersonic imho is also a question of the scenario. it doesn't make much sense to attack an enemy with aew-systems in a blue water scenario with subsonic ashm. It's highly unlikely that you can get your aircrafts close enough to start your "stealth" subsonic ashm and that these ashm travel for example further 250 km before been detected. imho in this scenario the best way is to go in fast, shooting as much supersonic ashm at max. range as possible and running away to see how the enemy deals with the missiles.
on the other hand in a littoral scenario i would prefare using multiple subsonic ashm with dual datalink on different flight paths with simultaneous impact time. (some of them can travel in a low flightpath over land etc.) i have the control of the attack all the time and i can ensure to hit the right target.

for sure some of that useful stuff could also be implemented to an supersonic ashm (iir, datalink etc.) but with more expense and less benefit. how useful is a dual datalink if there are only a few seconds between poping over the radar horizon and the impact?

btw it would be interesting to compare the export price for e.g. a brahmos and a c802. because if the weight and ship integration ratio is 4 to 1, whats about the price?

my private conclusion is that subsonic ashm stil are very useful and that supersonic ashm are also defeatable but if i have to fight a war against surface ships i would like to have both with me to choose the right tool for the right task. i don't know why no western navy at least develops a supersonic ashm, maybe because they think there is no real chance to need it!?

@talltower: afaik they quoted mach 4 at 70.000 ft. fast high flying targets with a terminal diving phase sounds to me like bmd fits to this thread.
any idea how they want to integrate a seeker if the surface reaches 1500°C or more?

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15 years

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The only point defense weapon available against supersonic cruise missiles is the rail gun.

Its projectiles can reach a velocity of at least 20 km/sec, guaranteeing an instantaneous hit probability. Also, more ammunition can be carried an a high ROF can be enabled, owing it its unique operating system.

http://www.ohgizmo.com/wp-content/uploads/2006/07/electric%20rail%20gun.jpg
http://www.navweaps.com/Weapons/WNUS_Rail_Gun_Slide_pic.jpg
http://ksjtracker.mit.edu/wp-content/uploads/2008/02/rail-gun-theory.jpg

Whoa, these railguns look sickly good as hell, and they would shoot down swarms of supersonic Sunburns, Yakhonts and Sizzlers coming at U.S. ships like clay pigeons.

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The small subsonic missiles are far more economical vs missile boats and other near defenseless targets, hypersonic missiles might be nigh unstoppable, but they are far to scarce and expensive to use vs defenseless targets.

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The small subsonic missiles are far more economical vs missile boats and other near defenseless targets, hypersonic missiles might be nigh unstoppable, but they are far to scarce and expensive to use vs defenseless targets.

But, like I said, such supersonic missiles are useful against defended high-value targets, like aircraft carriers, fortified bunkers and time-sensitive targets such as Scud TELs and S-300 SAM sites.

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19 years 2 months

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The only point defense weapon available against supersonic cruise missiles is the rail gun.

how many supersonic ashm have been shot down by an rail gun so far? oh i forgot there is no railgun fielded today ;)
afaik goalkeeper, phalanx, ram all were tested against supersonic targets.

supersonic is not hypersonic and today there is no hypersonic ashm. if somedays hypersonic ashm will enter service and if they will use a flightpath similar to a ballistic trajectory than bmd-system will fit this threat.

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19 years 3 months

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As trident was saying, people tend to forget that supersonics can have non-traditional trajectories/paths. They ain't exactly ballistic missiles. Late manouverability is a definite possibility. Add to that the fact that they can do the sea skimming bit either throughout their envelope (albeit at a lesser range) or during late stages.

If you want to go for HVAs, supersonic missiles do provide certain advantages. For others, subsonic ones are good enough.

USS>

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A couple factors work against gun-based anti-missile defense that were recognized in the early 1980s:

1. Gun systems have an inadequate ability to predict the incoming missile's future position. During the brief time while the gun projectiles are flying out, any subtle change in missile course will cause the projectiles to miss. It is especially difficult for the gun system to predict future missile position if the missile flies a random final trajectory that varies in 3 dimensions. (The Youtube.com videos you see of Phalanx shooting down mortar rounds in Iraq is easy because mortar rounds follow a 2 dimensional trajectory)

2. The throw weight of gun systems is often inadequate to stop an incoming missile. Even if you fill the missile full of holes so it stops guiding and won't explode, it is still a high speed ballistic mass of flammable material. If the ballistic blivet hits the ship, there will be a fire even if it doesn't explode (e.g. HMS Sheffield)

The above reasons are why modern defense systems use guided missiles like RAM, Aster, ESSM. Etc. to hit maneuvering ASHMs at distances that are not a danger to the ship.

i don't know why no western navy at least develops a supersonic ashm, maybe because they think there is no real chance to need it!?

Correction: the US and the UK don't. At least 3 other major Western navies had/have supersonic anti-ship missiles under development: France cancelled their ANF on cost grounds while Taiwan and Japan are in the process of fielding the HF-III and ASM-3, respectively. All of them have previously designed and introduced subsonic missiles, so they obviously agree with our assessment that the best course of action is to have a mix.

The small subsonic missiles are far more economical vs missile boats and other near defenseless targets, hypersonic missiles might be nigh unstoppable, but they are far to scarce and expensive to use vs defenseless targets.

If you want to go for HVAs, supersonic missiles do provide certain advantages. For others, subsonic ones are good enough.

Yes, I forgot to mention that, apart from the launch platform, the intended target also has a significant bearing on what the best choice would be. It all comes down to using the right tool for the job at hand, as radar says - if you can afford the luxury of having both, go for it!

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Correction: the US and the UK don't. At least 3 other major Western navies had/have supersonic anti-ship missiles under development: France cancelled their ANF on cost grounds while Taiwan and Japan are in the process of fielding the HF-III and ASM-3, respectively.

from my understanding the ANF was cancelled in an very early state but the ASMPA (nuclear standoff missile) went on so they have a good start if they want to continue with the ANF. i think the official statement was, that they might go on with ANF when the exocet reachs their end of life (~2015). if france finishs the ANF, it means that there is a western supersonic ashm available on the export market. (and it was planed that the ANF is more or less compatible to the exocet launchers etc. which means similar launch weight/size.

but for sure i missed the HF-III and the ASM-3. The ASM-3 is quoted to have a dual mode seeker (Active radar and iir).

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In the future, when railguns become operational, they would be slaved to computer guidance systems, enabling high accuracy shots.

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In the future, when railguns become operational, they would be slaved to computer guidance systems, enabling high accuracy shots.

It would be better if the rail gun launched a guided projectile.

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IRST.

;)

Which one? The 1 trillion dollar one the US has in space that can track everything on one side of the planet, which also doesn't exist?

Or the relatively short range ones that are commonplace in most military organizations?

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f... when the exocet reachs their end of life (~2015). ....

??? Exocet Block III is in production, & selling. Exocet will be around a very long time.

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relating to irst:
detection range for sirius is quoted as follows:
supersonic seaskimmer: 26,5 km
subsonic seaskimmer: 12 km
(tropical summer conditions)
source: world naval weapons systems

there is also a 360° fixed system offered by thales: artemis
(i think gatekeeper is more targeting asym. threats than ashm)

btw: the sirius pdf from thales also quotes:
"SIRIUS unsurpassed sensitivity and resolution inivite for many other tasks, e.g. [...] contribution to theatre ballistic missile defence" so we can assume that the detection range is a lot higher if the target is hot and flighing high.

@swerve:
i'm not sure were i read it but afaik this was the statement at the time they suspended anf. at this time the statement also was that anf is "on hold" but not cancelled. but for sure this may have changed until now and if the latest exocet block is selling well in 2015 there is no reason to take it from the market.

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19 years 1 month

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relating to irst:
...
@swerve:
i'm not sure were i read it but afaik this was the statement at the time they suspended anf. at this time the statement also was that anf is "on hold" but not cancelled. but for sure this may have changed until now and if the latest exocet block is selling well in 2015 there is no reason to take it from the market.

The latest Exocet block (III) is effectively a new missile, with turbojet rather than rocket propulsion, & more than double the range of its predecessor. It only entered service a couple of years ago, after ANF was cancelled, so it would seem unlikely that it would be dropped so soon.

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It would be better if the rail gun launched a guided projectile.

The projectiles are too small to have guidance systems, and with the extraordinarily high velocity of 20+ km/sec, it can hit any target in less than a few microseconds. The railgun has the advantage of higher rates of fire owing to its unique mechanism.

http://1.bp.blogspot.com/_VyTCyizqrHs/R7DumbGVTuI/AAAAAAAAAFI/0U0R1lPys_Y/s320/railgun-8.gif

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I miss Quake 3. When are they going to make handheld versions of these :D.

http://www.youtube.com/watch?v=iZg2vgGG8y8