Question about Hypersonic Missile Technology

Hello ATS,

Quick question for the aeronautical subject matter experts.

The threat of hypersonic missiles capable of delivering nuclear warheads seems to be an increasing concern. The concern being, as I understand it, that current surface to air countermeasures cannot achieve the speeds necessary to directly intercept and impact the inbound hypersonic projectile. I am also assuming that hypersonic countermeasures may not be able to achieve direct impact due to the relativistic speeds.

My question is - Instead of a direct impact counter measure like surface to air missiles or variations such as iron dome in Israel, could we not plot a hypersonic objects path and put-up clouds of flak or debris that it would then run into to either destroy or disable it?

a reply to: Overseeall

Well the idea of a nuke on a hypersonic missile has been around for decades. That's exactly what an ICBM is.

As for smaller missiles, it's complicated.
A harpoon missile, yes I know it's not hypersonic, is only 14" in diameter.
Now consider something that small moving at 5000 mph. It's not in any part of the sky for more than a blink of the eye so it's not easy to put something in it's path at the exactly right time to intercept it.

a reply to: Overseeall

All ICBMs are hypersonic, so the hypersonic threat has been around since the first ICBMs. The big change now is that we have boost glide weapons that use conventional warheads, that are capable of hypersonic speeds. They don't go as high as an ICBM, so they don't have the longer suborbital cruise period. They go into the upper atmosphere, but don't go out of it like an ICBM does. That gives them a quicker travel time. Existing antimissile systems have trouble with hypersonics because of the detection-reaction time loop. They're designed to stop missiles that are subsonic which have a longer travel time.

Instead of a direct impact counter measure like surface to air missiles or variations such as iron dome in Israel, could we not plot a hypersonic objects path and put-up clouds of flak or debris that it would then run into to either destroy or disable it?

The SM-2ER Block IV does exactly that. It's designed to stop up to medium range ballistic missiles in their terminal phase, and uses a blast fragmentation warhead to do it. The Block IV was further developed into the SM-6 and SM-6 Block IB, which increases the range, and uses a active radar seeker.

Raytheon is developing the Glide Phase Interceptor, and recently completed SRR-P on the program, and is moving into preliminary design. The GPI will use a Standard Missile, probably on an SM-6 booster package, and integrate with current Aegis SM inventories.

originally posted by: Bluntone22
a reply to: Overseeall

Well the idea of a nuke on a hypersonic missile has been around for decades. That's exactly what an ICBM is.

As for smaller missiles, it's complicated.
A harpoon missile, yes I know it's not hypersonic, is only 14" in diameter.
Now consider something that small moving at 5000 mph. It's not in any part of the sky for more than a blink of the eye so it's not easy to put something in it's path at the exactly right time to intercept it.

The way I figure it, is it is all down to the math. If we can hit a small orbiting object in space in the asteroid belt with a satellite, we can hit a hypersonic missile.

In my mind's eye I can picture putting up enough large clouds of flak along the projected path of a hypersonic projectile to score a hit. Imagine these clouds of flak then descending and stretching for miles vertically and horizontally as they disperse.

a reply to: Zaphod58

Thanks. You also got me thinking. I remember seeing laser technology as part of anti-missile defense. Since lasers travel at the speed of light is this too not an option? I guess you would need a very powerful laser to deliver enough energy to compromise the projectile.

originally posted by: Overseeall

originally posted by: Bluntone22
a reply to: Overseeall

Well the idea of a nuke on a hypersonic missile has been around for decades. That's exactly what an ICBM is.

As for smaller missiles, it's complicated.
A harpoon missile, yes I know it's not hypersonic, is only 14" in diameter.
Now consider something that small moving at 5000 mph. It's not in any part of the sky for more than a blink of the eye so it's not easy to put something in it's path at the exactly right time to intercept it.

The way I figure it, is it is all down to the math. If we can hit a small orbiting object in space in the asteroid belt with a satellite, we can hit a hypersonic missile.

In my mind's eye I can picture putting up enough large clouds of flak along the projected path of a hypersonic projectile to score a hit. Imagine these clouds of flak then descending and stretching for miles vertically and horizontally as they disperse.

Well it sounds easy.
But the logistics of what you suggest are staggering.
Back in the 80s the soviets had bombers to go after our carriers. They didn't plan on shooting one missile and hoping for the best, they would shoot a hundred. You wouldn't be able to put that much flak in the air to stop them.

And that asteroid has been on a set path for centuries so it wasn't exactly the same as a missile trying to evade.

a reply to: Overseeall

You don't need a lot of energy to compromise it, because it's already going to be at extreme temperature ranges during its flight. So you just have to push it past its ability to withstand heating from friction. A small amount of damage is going to go a long way when you're talking hypersonics. Some of the hypersonic tests we've carried out had some very interesting results when it came to temperature extremes.

a reply to: Bluntone22

Fair enough. Zaphod has listed some interesting options.

a reply to: Zaphod58

Excellent detail. I remember seeing a laser pod mounted on the nose of a Boeing 747..this must have been a decade ago on some popular science show.

Do you think the laser option as a viable defense mechanism, or more of the physical intercept via projectile, or both? I could see a fleet of aircraft equipped with the pods patrolling friendly airspace.

a reply to: Overseeall

It's a lot more than "the math". It's all about perception and logistics. If you are defending, you have to perceive the attack. That's why the attacks on Pearl Harbor and 9-11 were effective.

Logistics is having the right platforms in the right place to intercept the attack. At this time the most mobile platforms for defeating a hypersonic attack is an Aegis Cruiser or a Burke Class Destroyer with the right missile loadout. The missiles that Zap mentioned can be carried by those ships.

a reply to: JIMC5499

100% make sense. I didnt think it about as deeply as I should have when it comes to detection and presence of defense platforms.

a reply to: Overseeall

I was in the Navy in the 80's. The Falklands War had just ended. The Exocet missile used by Argentina had people worried. I was in a helicopter squadron that operated from carriers. There had been a major rush to get the CIWS and Sea Sparrow systems installed.

We played with a system that could detect the radar of an incoming sea-skimming missile. The idea was for us to fly at a certain altitude at a certain speed, while the ship would do a hard turn directly away from the missile. We would deploy chaff at a certain interval until the missile radar's repetition rate speeded up. Then we would turn directly towards the missile and climb. If everything worked the missile would either go into the water or lose track and fly off. Never tested it with a live missile. We did have an F-16 with a seeker head mounted on it fly a missile's profile. It should have worked.

a reply to: Zaphod58

what about the MARV warheads on Pershing II missiles, not all over the sky but moveable.

and that was what in the 70's-80's


why did the SR71 have high voltage electron beams on the tips of the inlet cones?

carbon-carbon or carbon-phenolic re-entry bodies can only take so much heat or shearing, there has to be more going on with them for them to get ALL the way to the ground and not break up or burn up.

here is a video of MIRVS coming back in look at all that plasma around them




they must make some sort of false bow shock in front of them to cut all the way into the atmosphere and survive and WORK not just a pile of slag.

a reply to: rwb8448

What's the big deal? The Mercury, Gemini and Apollo space craft all survived re-entry. Yes the shape of the RV forces air past the heat shield, reducing the heat. I saw a demonstration of one of the tiles from the Space Shuttle. They put a thermocouple on one side of the tile and hit it with a large torch on the other side. When the torch side was glowing the temperature had risen about 5 degrees F. This is all 60's and 70's tech.

Electron beams on the tips of the SR-71's Aerospikes? I'd love to see where you came up with that one.

I used to have a side business doing heat and flow modeling. It's amazing how a small change in flow or direction effects temperature.

a reply to: JIMC5499

more thermal mass in a manned re entry craft also ablative coatings.


you can burn the shell of a MIRV away to shed heat considering what is inside of it?

as far as the SR71 simple google search will fill you in on that, or someone here will.

its more the tip if the MIRV's that I'm interested in, if it were some sort of ablative sacrificial tip that also created a false bow shock to protect the back of the MIRV i guess that would make sense MAYBE.

as you know ONE little notch or unevenly burned section on effectively the only point the MIRV touches the air(nose) would send them tumbling or just cause a fatal hot spot.

originally posted by: Overseeall
Hello ATS,

Quick question for the aeronautical subject matter experts.

The threat of hypersonic missiles capable of delivering nuclear warheads seems to be an increasing concern. The concern being, as I understand it, that current surface to air countermeasures cannot achieve the speeds necessary to directly intercept and impact the inbound hypersonic projectile. I am also assuming that hypersonic countermeasures may not be able to achieve direct impact due to the relativistic speeds.

My question is - Instead of a direct impact counter measure like surface to air missiles or variations such as iron dome in Israel, could we not plot a hypersonic objects path and put-up clouds of flak or debris that it would then run into to either destroy or disable it?

The term “hypersonic” simply means “moving 5 times or more faster than the speed of sound”. When a ballistic missile warhead re-enters the atmosphere it is moving at high hypersonic speeds, and it is possible to intercept it with a kinetic kill vehicle, if you can predict the path it is on with sufficient accuracy. With ballistic missiles, they are lofted high out of the atmosphere on a parabolic arc before they re-enter, and during that arc they are detectable by ground based radar and IR trackers.

When people talk about the threat of hypersonic missiles today, they are actually talking about a trajectory in which the warhead is lofted outside the atmosphere and it re-enters the atmosphere hundreds or thousands of kilometers from the target. It then performs a pull-up maneuver and glides hypersonically toward the target on a more-or-less horizontal trajectory. A hypersonic glider can be killed about as easily as a pure ballistic warhead, IF you can detect it and track it accurately enough and soon enough to launch an interceptor. The problem is that ground based radars and IR trackers can’t see a hypersonic glider far enough away to allow enough time for an interceptor launch.

That’s why the US is developing fleets of small, low orbit satellites that can look out and downward from the horizon to detect and track hypersonic gliders with enough warning time. It’s not impossible, it’s just something we’ve not tried to defend against before. The decision was made in 2018 to get the US in the hypersonic glider game both offensively and defensively. All three military services are developing a version of offensive hypersonic gliders and the Missile Defense Agency is developing the satellite constellations.

a reply to: rwb8448

The tip of a MIRV is protected from the heat because of it's base. MIRVs re-enter the same as space capsules. Their bottom side first.

originally posted by: rwb8448
as far as the SR71 simple google search will fill you in on that, or someone here will.

There were TWO A-12s that tested electron beams. There were no SR-71s that used it, as it was not installed on any aircraft outside of the test program. Under Kempster A, the electron gun used was too large to fit anywhere but in the payload bay, and could only shoot straight down. Under Kempster B, Westinghouse developed the C-Gun. Its first flight was a failure after the panels opened, but the gun suffered a power failure. The second test was successful but details were classified. The CIA developed an EW suite for the A-12 and killed Kempster after more research into A and B. The SR-71 already had an advanced EW suite, that the USAF refused to share with the CIA, which is why Kempster took place in the first place.

a reply to: JIMC5499

not any more.

MMIII come in nose first

the back of a MMIII warhead is metal and the carbon carbon, and carbon-phenolic are at the front(where the heat is).


the use gas generators in the back to spin up the warhead before it enters the atmosphere, if what your saying is true the MIRV's would more than likely tumble.

the older warheads like on ATLAS were city killers and were also quite large, so they did come in like space capsules.

a reply to: Zaphod58

but they were still there.

and tested and flown and at least once 'worked'. would love to see if there were and superconducting magnets in the A-12's engine area.

i spoke to a sled driver if he thought they would hit M. 4 and he said with out a doubt.