Potential Home Video of Recently Reported Hypersonic Kinzhal Missile

[386]

I wasn't sure if this belongs here or in the Russia/Ukraine specific forum (posting here because it's about identification rather than political).

If I hadn't just read news reports an hour ago of the hypersonic missile, I would have considered this video looking fake. Can any experts chime in on whether or not this is what something like a Kinzhal would look like?

 

[jarlrmai]

Hypersonic stuff has to travel high, this could just be a normal air to ground or air to air missile or similar standard ordnance. Actually given the arc on the trail could be ground launched.

 

[386]

Hypersonic stuff has to travel high, this could just be a normal air to ground or air to air missile or similar standard ordnance.

That was one of my many initial questions, I was curious about altitude, then the timing of the sonic boom, etc... Then I realised I'd be best off letting you guys analyse the validity.

 

[Mauro]

Probably not a Kinzhal I think. The Kinzhal is launched from an airplane from a great height and for what I know hypersonic weapons are powered only during the first part of their flight. In the video we see a low-flying missile: if it were an hypersonic weapon that would be the terminal part of the flight, but in this case the rocket motor would be already off (and I guess its trajectory would be much steeper and faster). It looks more like a supersonic cruise missile to me, of which Russia has many types, ie. the P-800 Oniks, even if, for what I know, they are all primarily intended for anti-ship use (and I'm also not sure if the massive exhaust of the missile in the video is compatible with the ramjet which powers the Oniks).

Anyway the Kinzhal too is primarily intended for anti-ship use, and Russia surely did not need to use a sophisticated weapon like this in the Ukrainian theater, given Ukrainian air defence has about zero capabilities even against more conventional ballistic missiles such as the Iskander (*). It may very well be that their stores of long-range missiles are starting to run dry and they're compelled to use weapons which are sub-optimal/overkill for the intended role.

(*) while they have some capability against cruise missiles, if they are supersonic of course this makes things worse

 

[FatPhil]

Lower things look faster as they're zooming past, simply because they have a higher angular speed. That looked quite low, and to be honest not that fast. Humans are notoriously bad at estimating speeds of roughly pointlike objects, and that includes me. (Though I'd like to think that having been a pedal- and motor-cyclist has honed my perception somewhat, because it is a necessary survival trait.)

 

[Mendel]

There are two boom sounds in the video, which is one too many for a hypersonic boom, so one of these is probably an explosion (or artillery fire). And when there's one explosion, there may be two?

I think the boom doesn't sound like sonic booms I've heard, but it's been awhile.

 

[Mendel]

Where was the video taken, and what direction did the object travel?

Article:

"The Kinzhal aviation missile system with hypersonic aeroballistic missiles destroyed a large underground warehouse containing missiles and aviation ammunition in the village of Deliatyn in the Ivano-Frankivsk region," the Russian Defense Ministry said Saturday.

Source: https://www.themoscowtimes.com/2022/03/19/russia-uses-advanced-hypersonic-missiles-in-ukraine-for-the-first-time-a77000

 

[Mendel]

the timing of the sonic boom,

you can get the approximate altitude/distance from the timing via the speed of sound and the delay between when the object is seen overhead and when the boom is heard.

the angular velocity would then yield the speed.

 

[FatPhil]

you can get the approximate altitude/distance from the timing via the speed of sound and the delay between when the object is seen overhead and when the boom is heard.

the angular velocity would then yield the speed.

sin(elevation on hearing boom) = 1/mach_number
e.g. mach 1 => overhead, mach 2 => 30 degrees

 

[Mendel]

mach 1 => overhead

If you diagram this, you get an isosceles triangle, not a right triangle, and that makes the derivation at https://www.grc.nasa.gov/WWW/K-12/airplane/machang.html wrong.

 

[FatPhil]

If you diagram this, you get an isosceles triangle, not a right triangle, and that makes the derivation at https://www.grc.nasa.gov/WWW/K-12/airplane/machang.html wrong.

I get a degenerate triangle, and the cone is a plane.

https://upload.wikimedia.org/wikipedia/commons/b/b3/Sonic_boom.svg
https://upload.wikimedia.org/wikipedia/commons/2/25/Mach_cone.svg

 

[Ann K]

There are two boom sounds in the video, which is one too many for a hypersonic boom, so one of these is probably an explosion (or artillery fire). And when there's one explosion, there may be two?

I think the boom doesn't sound like sonic booms I've heard, but it's been awhile.

At the end of the clip is a visible mountain (but I don't know if there are unseen ones behind the viewer), so an echo would appear to be a probable cause of the second sound. I've lived at the base of the Organ mountains in New Mexico, and a crash of thunder (or a Fourth of July firework) was always followed by a series of echoes of diminishing volume.

 

[Domzh]

maybe the sound is not a sonic boom