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It's a hypersonic thruster, i.e. 5 or more times the speed of sound. Far too fast for civil aviation. It's probably even too fast for "safe" manned flight. This is the speed at which the air ionizes around the vehicle. It's like flying inside a fireball.

The first use that comes to mind is a hypersonic cruise missile or unmanned bomber.

Intercontinental missiles are also hypersonic, but their re-entry vehicles are gliders with limited maneuvering capabilities.

The Russians have developed and used hypersonic air-to-ground missiles in Ukraine, the Kinzhal. It is very difficult to intercept a missile at these speeds, and almost impossible if the missile is maneuverable. This has re-launched research into this type of missile and propulsion system.

Russia is ahead in this field. The USA, China and France have carried out various experiments (mach 5 to 25), but do not really have combat-ready hypersonic weapons.

One of the great difficulties of hypersonic flight is that you generally need one engine and one stage per flight regime. The majority of demonstrators operate according to the following scheme:

- a rocket or aircraft propels the vehicle to supersonic speed, so that it can start its engine.

- The vehicle accelerates to Mach 5. The vehicle starts its hypersonic engine and detaches from the supersonic stage.

- Climb to the edge of space.

- Descent and acceleration.

- Detachment from the hypersonic engine and final gliding approach. The fireball moving off at mach 20 kind of approch.

The engine shown here would enable to have just one engine for supersonic and hypersonic flight, greatly simplifying the vehicle. The fact that it's an engine and not a rocket is important, as it means that the thrust is much longer and can potentially last for the whole flight. At these speeds, it's largely the engine's thrust that makes maneuvering possible, and this is what distinguishes these vehicles from the hypersonic glider/reentry vehicle found on intercontinental missiles.




If you define "hypersonic weapon" as merely traveling at or beyond Mach 5, then practically every medium range ballistic missile since the V-2 qualifies. There is nothing special about a missile that can hit hypersonic speeds.

The real difference is maneuvering, but most of Russia's "hypersonic weapons" cannot actually do this. Hence why Ukraine has shot down nearly every Khinzal that has been fired at Kyiv and about half of the Zircon missiles too, using technology that has existed for decades. IIRC one of the Khinzal missiles was even knocked out by a PAC-2 missile, which wasn't designed for that purpose.

Maybe AvanGuard is more competent and less overrated/overhyped than their other efforts, but there's no particularly good reason to believe that. Meanwhile the last time the US successfully tested a hypersonic weapon it was immediately greenlit for serial production, and I don't think that's because they are freaking out so much as that the US sandbags our capabilities while some of our competitors inflate theirs. You claim the Russians are ahead, but they keep putting their hypersonic engine researchers in jail. I don't buy it.


> The Russians have developed and used hypersonic air-to-ground missiles in Ukraine, the Kinzhal. It is very difficult to intercept a missile at these speeds, and almost impossible if the missile is maneuverable.

Speed does not make hypersonic missiles difficult to intercept. They are considerably less maneuverable than slower missiles due to the limits of material physics. The primary advantage of hypersonic weapons is that it reduces the available reaction time of the target such they may not be able to respond effectively or mount a defense. Any "difficulty of intercept" is predicated on there not being enough time to execute the intercept after the missile is detected. US air defense systems have very low reaction latencies by design, as demonstrated in Ukraine.

I am unclear why anyone thinks Russia is ahead in this field, beyond their penchant for marketing ballistic missiles like Kinzhal as "hypersonic". The US has been building and testing hypersonic weapon systems longer than most people have been alive. Unlike Russia, the US requires hypersonic missiles to have precision terminal guidance, which is an extremely difficult engineering problem within the atmosphere. It took decades for the US to figure out how to reliably deliver terminal guidance for hypersonics.


> It's a hypersonic thruster, i.e. 5 or more times the speed of sound. Far too fast for civil aviation. It's probably even too fast for "safe" manned flight. This is the speed at which the air ionizes around the vehicle. It's like flying inside a fireball.

Ionization occurs at considerably higher temperature.

The hypersonic regime is described as when vibrational excitations of air molecules begin to significantly affect the specific heat. After that, dissociation sets in, and only after that does ionization become significant. Temperature ranges, as I understand it, are (for air at 1 bar):

Vibrational excitations: > 800 K

Dissociation of oxygen: > 2500 K (nearly complete ~4000 K)

Dissociation of nitrogen: > 4000 K (nearly complete ~9000 K)

Ionization: > 9000 K

Lower pressure will reduce the temperatures at which dissociation and ionization become significant.


Kinzhal isn’t really a true hypersonic weapon. They just strapped an iskander tbm to a su34, which is why the pac3 patriot interceptors can actually shoot them down, they were developed to intercept tbms.


well you still get the marginal benefit of having a mobile launch platform that travels at mach 1, which makes it a bit easier to avoid static air defenses if you know where they are. (assuming your adversary can't track and destroy your aircraft before they get a chance to launch them)


It’s like the US was yeeting Lance missiles from F-106s and insisting that it’s a hypersonic weapon and it’s ahead of everyone else. Pathetic.




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