Wait, what? Whose fighter jets are those?

[berkeman]

Those don't look like US fighter jets that I'm familiar with (but I could be wrong). Who is launching these US hypersonic missle tests?

https://www.cnn.com/2022/07/13/politics/us-hypersonic-tests/index.html

(CNN)The Pentagon carried out successful tests of two different hypersonic missiles systems recently, the US Air Force and Defense Advanced Research Projects Agency (DARPA) announced Wednesday.

The AGM-183A Air-launched Rapid Response Weapon (ARRW) had its second consecutive successful test on Tuesday after a series of testing failures earlier in the program. An Air Force program, the ARRW is a boost-glide system that uses a rocket to accelerate a missile to hypersonic speeds before releasing a hypersonic glider which coasts toward the target at speeds in excess of Mach 5.

 

[Frabjous]

They are Russian.

 

[berkeman]

Yeah, update -- I watched the CNN video and it's worthless. Sigh.

 

[Benjies]

I'd entertain the idea that this DAPRA developed hypersonic system is actually a solid-fuel ramjet (SFRJ). Though the dynamic pressure and flight corridor aren't disclosed in the article you linked, the cruise Mach number and the rocket boost would meet the theory that this system used a nozzleless rocket boost to elevated Mach after being dropped from an airborne system, and then proceeded to use an SFRJ to reach glide Mach.

I wrote a MATLAB project outlining an SFRJ sustaining glide at around Mach 4.2, however it wouldn't surprise me one bit to hear that advancements and refinements to the SFRJ would enable it to cruise around Mach 5. Of course, an over-propulsed rocket system could have been used and/or a scramjet, however I find these less feasible at cruise Mach 5.

 

[Rive]

Who is launching these US hypersonic missle tests?

That's supposed to be a Russian Kinzhal on a MiG-31
BBC

 

[Jodo]

Definately Russian MIG 31's.

 

[boneh3ad]

Those don't look like US fighter jets that I'm familiar with (but I could be wrong). Who is launching these US hypersonic missle tests?

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https://www.cnn.com/2022/07/13/politics/us-hypersonic-tests/index.html

Those are MiG-31K jets carrying Kh-47M2 Kinzhal aero-ballistic missiles. They're the light beer of hypersonic missiles and you could argue they don't really qualify. But pictures like this exist in the public domain so that photo gets used a lot.

 

[boneh3ad]

I'd entertain the idea that this DAPRA developed hypersonic system is actually a solid-fuel ramjet (SFRJ). Though the dynamic pressure and flight corridor aren't disclosed in the article you linked, the cruise Mach number and the rocket boost would meet the theory that this system used a nozzleless rocket boost to elevated Mach after being dropped from an airborne system, and then proceeded to use an SFRJ to reach glide Mach.

I wrote a MATLAB project outlining an SFRJ sustaining glide at around Mach 4.2, however it wouldn't surprise me one bit to hear that advancements and refinements to the SFRJ would enable it to cruise around Mach 5. Of course, an over-propulsed rocket system could have been used and/or a scramjet, however I find these less feasible at cruise Mach 5.

Per the article, "greater than Mach 5" and "[t]he Air Force did not specify how fast the ARRW flew." It is also specifically mentioned as a boost glide system.

 

[Benjies]

Per the article, "greater than Mach 5" and "[t]he Air Force did not specify how fast the ARRW flew." It is also specifically mentioned as a boost glide system.

A ducted SFRJ with an aft-mixing region has space for nozzleless SRM boost. And I still would argue that a sustain phase beyond Mach 5 may be feasible with a ramjet. One could muse about a solid-fuel scramjet but I know nothing about this combined cycle if it exists, feel free to inform me if such a system exists.

Here's a similar system called a throttleable ducted rocket. I only drop the comment to provide some insight I'd gained from my work on the project. We're talking about hypersonics and systems that we can only discuss the design of in theory. Just having some fun while trying to provide some insight- combined cycles always fascinate me, and with system requirements for hypersonics only becoming more stringent I choose to ignore Occam's razor and assume that some far more fascinating combined cycles already exist. By principle I choose to ignore the thought experiment of what this system would look like if it were just an SRM- haha!

 

[boneh3ad]

A ducted SFRJ with an aft-mixing region has space for nozzleless SRM boost. And I still would argue that a sustain phase beyond Mach 5 may be feasible with a ramjet. One could muse about a solid-fuel scramjet but I know nothing about this combined cycle if it exists, feel free to inform me if such a system exists.

Here's a similar system called a throttleable ducted rocket. I only drop the comment to provide some insight I'd gained from my work on the project. We're talking about hypersonics and systems that we can only discuss the design of in theory. Just having some fun while trying to provide some insight- combined cycles always fascinate me, and with system requirements for hypersonics only becoming more stringent I choose to ignore Occam's razor and assume that some far more fascinating combined cycles already exist. By principle I choose to ignore the thought experiment of what this system would look like if it were just an SRM- haha!

A boost glide system is unpowered after the initial boost phase. It's a glider strapped to a rocket booster.

 

[Benjies]

A boost glide system is unpowered after the initial boost phase. It's a glider strapped to a rocket booster.

Oh yikes, I was thinking of Boost-sustain. My bad.

 

[hutchphd]

OMG there's a hypersonic wind-tunnel gap. Don't tell Chicken-Little...

 

[boneh3ad]

Oh yikes, I was thinking of Boost-sustain. My bad.

Those are under development but are not what ARRW or OpFires are.

 

[boneh3ad]

OMG there's a hypersonic wind-tunnel gap. Don't tell Chicken-Little...

Allegedly the shiny new wind tunnel that China has been bragging about can't run reliably because the local power grid can't support it. 🤣

 

[etudiant]

Allegedly the shiny new wind tunnel that China has been bragging about can't run reliably because the local power grid can't support it. 🤣

Seem to remember that some big US tunnels had similar issues, so they were mostly run at night, when demands was low.

 

[boneh3ad]

Seem to remember that some big US tunnels had similar issues, so they were mostly run at night, when demands was low.

Most of the really power hungry US tunnels were built near TVA dams to provide abundant power, but there are definitely some that can only run at night.

The important point is that this is a predictable, well-publicized issue so it's a bit surprising.

 

[cjl]

Those are MiG-31K jets carrying Kh-47M2 Kinzhal aero-ballistic missiles. They're the light beer of hypersonic missiles and you could argue they don't really qualify. But pictures like this exist in the public domain so that photo gets used a lot.

This is my new favorite way to describe the Kinzhal (really just a theater ballistic missile with modified guidance strapped to the bottom of a jet).

 

[boneh3ad]

This is my new favorite way to describe the Kinzhal (really just a theater ballistic missile with modified guidance strapped to the bottom of a jet).

There's a whole lot of misinformation (or, in this case, disinformation) out there. I get it, since it's a highly technical topic, but as someone familiar with the field, it is frustrating.

 

[cjl]

There's a whole lot of misinformation (or, in this case, disinformation) out there. I get it, since it's a highly technical topic, but as someone familiar with the field, it is frustrating.

Yeah, hypersonics have become the new buzzword, and a lot of people don't seem to realize it's not simply the act of traveling faster than mach 5 that makes some of the new research and development interesting and groundbreaking.

Hell, the AIM-54 Phoenix is very nearly a hypersonic weapon (depending on launch conditions and exact flight profile) if your only criterion is "weapon that travels above mach 5". For that matter, modern APFSDS tank rounds are borderline too.

 

[Flyboy]

Here's a similar system called a throttleable ducted rocket. I only drop the comment to provide some insight I'd gained from my work on the project. We're talking about hypersonics and systems that we can only discuss the design of in theory. Just having some fun while trying to provide some insight- combined cycles always fascinate me, and with system requirements for hypersonics only becoming more stringent I choose to ignore Occam's razor and assume that some far more fascinating combined cycles already exist. By principle I choose to ignore the thought experiment of what this system would look like if it were just an SRM- haha!

A bit late to the party, but I know they've got a currently fielded TDR in the MBDA Meteor BVRAAM. It's a particularly nasty missile to be on the receiving end of, and a damn clever bit of engineering. High-thrust boost phase nozzleless SRM tucked into the aft, and a solid-fuel gas generator at the middle feeding into the now-empty boost motor cavity, where it mixes with air fed by a pair of intakes on the "bottom" of the missile. I don't think it's hypersonic, but it gets pretty close.