Hypervelocity missiles

Some technologies are very promising, but stay immature seemingly forever without entering service (or enter service very late, and in small numbers).

Supersonic air transport, maglev trains and fusion power are some civilian examples.

Cased telescopic munitions smaller than 25mm calibre, caseless ammunition, turreted mortars, lethal combat lasers, liquid propellants for guns, autonomous killer drones and small hypervelocity missiles military examples of such enticing, yet not really successful ideas.

Small hypervelocity missiles have three promising applications (antitank, anti-air and anti-tank), and the anti-tank role seems to be the one that got the most R&D.

Several nations have researched small hypervelocity missiles. Projects from the USA, Germany, Sweden and Canada were apparently most published. Such research work dates back by decades - at least into the 70's.

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These missiles are promising because of a gun's limitations; a gun tends to become heavier, larger and more expensive with higher performance. Missiles become superior at some point because they accelerate in the air (requiring no or just a very short barrel) with lesser propellant pressures. That's why we have intercontinental missiles but no intercontinental guns. The cannons of main battle tanks approach impractical sizes as well. We're at 120-125mm calibre since the early 80's, and that's actually not really more than we already had reached in WW2 (37-128mm high velocity guns) in production. The pressures became higher, the projectiles more advanced, the barrels longer - yet it's difficult to add more than incremental advances without a larger calibre. There are 140 and 152mm high velocity tank guns, but their disadvantages prevented an introduction so far. A hypervelocity missile (HVM) could propel the same penetrator as a gun can, and do so at an even higher speed. That leaves little doubt about its ability to defeat tanks as well as guns can do, but the mix of advantages and disadvantages would be very different. HV AT missile advantages:
* usually mounted outside of the main armour
* several missiles ready for quick ripple fire
* higher possible penetrator velocity
* less weapon weight
* no barrel durability issues

Tank high velocity gun advantages:
* possibly more compact ammunition
* smaller firing signature
* more mature technology (technological lock-in)
* likely lower cost of ammunition
* no minimum range

 I expect that at some time we'll see relatively light armoured vehicles armed with anti-tank (AT) HVM in addition to a rather modest gun armament. My speculation on the T-95 last year was one such example. This combination would exploit the gun's advantages for most tasks and exploit the HVM technology only for the high-end AT purpose. The most promising publicly known HVM to date seems to be the CKEM project for an AT HVM with the size and weight of a common ATGM.

The ripple fire capability would enable ambushes where one firer could threaten several tanks with destruction at once. That would likely rarely happen in actual combat, but it would be an additional motivation for careful, dispersed and bounding tank tactics. The ripple fire capability has a second advantage, too: No projectile is 100% safe from the most advanced active protection technology, but even that cannot defeat several approaching missiles in quick succession. These protection systems can affect several tank gun-launched long rod penetrators because of the several second interval, but their chance against several missiles impacting in one or two seconds would likely be to the intercept of the first, maybe also second missile. The high velocity (mach five to seven) of such missiles could also overwhelm other defensive capabilities like ship anti-air defences or an aircraft's ability to react to an incoming missile by fooling and dodging it.  

Hypervelocity missiles may be a great, underestimated and neglected technology with exciting new options and an answer to existing problems. It may just as well be a Rube Goldberg technology that's fascinating only at first glance. I keep being interested in HVMs because I've got a deep-rooted suspicion about conservatism in military procurement.

1 comment:

  1. I think you were right on the money with the first sentence of this post. HVMs are promising, but may stay immature forever. The need just isn't high enough to justify the cost of perfecting the technology.

    Long-range, non-line-of-sight systems like NLOS-LS, Spike-ER, and Polyphem appear to offer more near term utility at less cost and risk, and are useful for more than just killing tanks.