Has there been an attempt to use an air-to-air missile for defense?

[Elysium]

I just had a brainwave - would it be feasible to use existing (or maybe future), such as the AIM-120 or R-77 air-to-air missiles to intercept the missiles of opposing aircraft?
The targeted aircraft would fire upon the incoming missile, and began evasive manuevers. It could even fire multiple ones, and if the enemy missile was destroyed, the remaining ones could recommit to the enemy aircraft.
I would say yes it would be immensely viable, since the two missiles would head straight for each other. Even if the interception wasn't successful, de added duty of having to evade an enemy missile would drain so much kinematic energy from the attacking one, that the targeted aircraft could easily escape it.

It makes tremendous sense to me, and I think it would be possible to do with hardware that exists today, or some minor evolution of it.
What do you think of this idea, has it been tried before? It just makes so much sense, that I'd be surprised if the major militaries didn't think of it, unless I'm missing something.

 

[Scott Kenny]

In theory, yes it'd work.

In practice, well, an IR guided missile has very low signature. Similarly, a SARH missile is almost invisible from head on. Neither one is actively emitting anything, there's only passive heating to try to track. And they're physically a very small object to try to get a radar lock on.

 

[Elysium]

I'm not sure detection would be such a huge issue. I'm sure a lot has been invested in tracking incoming missiles and all existing aircraft has such warning systems, not sure what would it take to upgrade them for a weapons-quality lock.
There's a ton of signals to work with for radar guided missiles, both of the active and semi-active variant.
For IR missiles, you'd have to remember, they are quite short range. An object from 10km has ~600 times the RCS it would have at 100km, which would turn a tiny missile into fighter sized target.

And don't forget, missiles have big hot rocket motors, I'm sure those can be tracked.

And I'd say this idea would be most useful for BVR, for ranges where IR missiles don't yet come into play.

 

[Archibald]

In theory, yes it'd work.

In practice, well, an IR guided missile has very low signature. Similarly, a SARH missile is almost invisible from head on. Neither one is actively emitting anything, there's only passive heating to try to track. And they're physically a very small object to try to get a radar lock on.

Plus AAM are insanely fast: mach 3, Mach 4, if not Mach 5. The closing velocities with a Mach 2 aircraft are just crazy. Not much time to throw a missile against the incoming missile.
There is a reason why defense against AAM has gone the passive way; chaff first, then ECM and decoys, including towed.

 

[Elysium]

Good point. But I still think there's something to be gained there. First, ships already need to contend with ASMs that can do upwards of Mach 2 and more. Soviet ASMs in the 80s were pushing Mach 3. Additionally ships are hulking immobile targets, yet as far as I know, modern ships have a reasonably effective defenses against them. Likewise there exist systems that can shoot down ICBMs in the descent phase. Also the Patriot and S400s are a thing, and those allegedly can shoot down super and hypersonic missiles.
I'd say building an anti-AAM system is easier than both of these things for the following reasons:

1. AAMs in the terminal phase tend to be carried by inertia and lose significant speed when forced to manuever - just forcing the enemy missile to make manuevers that make its original target impossible to hit would mean success
2. It doesn't need to be 100% effective. If a hypothetical AAM can shoot down a cooperative target at 200km, a Mach 1 fighter at 100km, then if such a system can reduce its effective range to 50km, it has already justified itself
3. The enemy missile is literally flying towards you, and you are flying away from it, which gives you a huge delta-V advantage.

I feel like there's a large design space for these missiles, depending on what phase of flight you want to do the intercept, and how you want to do this (close or far, one missile with a big warhead, or multiple small ones etc.).

I'd be surprised if there isn't at least a study on the feasibility of this idea, unfortunately, I'm not good at digging up stuff like this, but I'd guess this forum is full of folks with erudite knowledge on obscure aerospace topics.

 

[TomS]

Good point. But I still think there's something to be gained there. First, ships already need to contend with ASMs that can do upwards of Mach 2 and more. Soviet ASMs in the 80s were pushing Mach 3. Additionally ships are hulking immobile targets, yet as far as I know, modern ships have a reasonably effective defenses against them. Likewise there exist systems that can shoot down ICBMs in the descent phase. Also the Patriot and S400s are a thing, and those allegedly can shoot down super and hypersonic missiles.
I'd say building an anti-AAM system is easier than both of these things for the following reasons:

1. AAMs in the terminal phase tend to be carried by inertia and lose significant speed when forced to manuever - just forcing the enemy missile to make manuevers that make its original target impossible to hit would mean success
2. It doesn't need to be 100% effective. If a hypothetical AAM can shoot down a cooperative target at 200km, a Mach 1 fighter at 100km, then if such a system can reduce its effective range to 50km, it has already justified itself
3. The enemy missile is literally flying towards you, and you are flying away from it, which gives you a huge delta-V advantage.

I feel like there's a large design space for these missiles, depending on what phase of flight you want to do the intercept, and how you want to do this (close or far, one missile with a big warhead, or multiple small ones etc.).

I'd be surprised if there isn't at least a study on the feasibility of this idea, unfortunately, I'm not good at digging up stuff like this, but I'd guess this forum is full of folks with erudite knowledge on obscure aerospace topics.

There have been a few. The B-70 was supposed to have a self-defense missile called Pye Wacket that could engage both enemy fighters and long-range SAMs. Not clear whether AAMs were in its wheelhouse, but the large ones the Soviets used on interceptors might have been.

Pye Wacket - Wikipedia

en.wikipedia.org

Much more recently, there is the Raytheon/USAF Miniature Self-Defense Missile (or Munition) project, which is intended to use a small hit-to-kill interceptor to defeat incoming SAMS and AAMs.

Tiny Missile Interceptor To Defend Aircraft Against Enemy Missile Attacks Moves Forward

These miniature weapons could provide a robust hard-kill defensive option for everything from stealth fighters to bombers to tankers.

www.twz.com

That article mentions some other candidates as well.

No doubt there have been others over the years that I'm forgetting.

 

[Avimimus]

A lot of missiles in the terminal phase will have burnt through their fuel (i.e. their engine will just have residual heat, no reaction) and the closing speeds will be lower (as they are coasting at that point).

I'd suspect a big issue might be fusing - a missile is a much smaller target than an airplane, and a warhead may have to be passing closer and have a better timed detonation in order to have an effect.

I could see potential for the development of a smaller interceptor to go after the bigger long-ranged missiles (i.e. S-400, Patriot interceptors). However, it'd be a challenge.

P.S. Hasn't there already been an attempt to defensively shoot down a SAM with an AAM? Didn't that happen in Kosovo? Or did I mishear something?

 

[Scott Kenny]

Good point. But I still think there's something to be gained there. First, ships already need to contend with ASMs that can do upwards of Mach 2 and more. Soviet ASMs in the 80s were pushing Mach 3. Additionally ships are hulking immobile targets, yet as far as I know, modern ships have a reasonably effective defenses against them. Likewise there exist systems that can shoot down ICBMs in the descent phase. Also the Patriot and S400s are a thing, and those allegedly can shoot down super and hypersonic missiles.

Ships have an advantage in that their defense systems can be a lot bigger, and there's more or less no concern for how much drag they produce. So you can have Phalanx CIWS and Sea Sparrow box launchers just sitting there. Relative wind over a ship is usually under 30knots.

The other advantage ships have is that antiship missiles are a LOT bigger than anything short of the monster SA5 et sim.

I'd say building an anti-AAM system is easier than both of these things for the following reasons:

1. AAMs in the terminal phase tend to be carried by inertia and lose significant speed when forced to manuever - just forcing the enemy missile to make manuevers that make its original target impossible to hit would mean success
2. It doesn't need to be 100% effective. If a hypothetical AAM can shoot down a cooperative target at 200km, a Mach 1 fighter at 100km, then if such a system can reduce its effective range to 50km, it has already justified itself
3. The enemy missile is literally flying towards you, and you are flying away from it, which gives you a huge delta-V advantage.

I feel like there's a large design space for these missiles, depending on what phase of flight you want to do the intercept, and how you want to do this (close or far, one missile with a big warhead, or multiple small ones etc.).

Stealth does the greatest work in terms of reducing AAM effective range. If you can't get a radar lockon until 50km, you don't need a 200km range AAM (and should be carrying 2x50km range AAMs in place, they weigh about the same as 1x200km range AAM). Of course, there are still a lot of pre-stealth aircraft in service right now, so the 200km range AAM is still useful when that's your threat profile.

 

[BritishPerson]

I just had a brainwave - would it be feasible to use existing (or maybe future), such as the AIM-120 or R-77 air-to-air missiles to intercept the missiles of opposing aircraft?
The targeted aircraft would fire upon the incoming missile, and began evasive manuevers. It could even fire multiple ones, and if the enemy missile was destroyed, the remaining ones could recommit to the enemy aircraft.
I would say yes it would be immensely viable, since the two missiles would head straight for each other. Even if the interception wasn't successful, de added duty of having to evade an enemy missile would drain so much kinematic energy from the attacking one, that the targeted aircraft could easily escape it.

It makes tremendous sense to me, and I think it would be possible to do with hardware that exists today, or some minor evolution of it.
What do you think of this idea, has it been tried before? It just makes so much sense, that I'd be surprised if the major militaries didn't think of it, unless I'm missing something.

There are a few SAM's that have used air to air missiles, Ukraine has been given some trucks which have ASRAAM missiles on them and they have shot down some Shahed drones.