DARPA's hypersonic scramjet achieves successful flight

I'm not convinced you want air breathing missiles for interception, you want solid rockets or something of that sort. There are Standard Missiles (SM-3) faster than Zircon, although they are for BMD defense.

Faster ESSM/SM-2/SM-6 could be developed, and reaction time could be lowered.

This is instead the equivalent to the Zircon.

Not quite sure why interceptor missiles would have to "fly fast enough to catch up" unless you're shooting at a missile departing from you (that is to say, unless you actually have to catch up with something).

No. Russian Zircon is to deal with the next after nuclear strategic threat to Russia - US aircraft carrier groups. US pursue hypersonic weapons for different purpose - fast global much less than nuclear strike capability, ie. being able to strike any given target anywhere in like under half an hour. And thus not really much of hypersonic development in US - the cheap ballistic would do it better, especially with SpaceX driving down the cost of it. DOD is already excited that almost immediate delivery of 100ton, ie. instead of several C-130, payload by Starship anywhere in the world looks to be under $50M.

Pretty much and a counter against Chinese Hypersonic glide vehicles.

Plasma stealth is an existing approach to radar stealth that is made easier by hypersonic speeds.

Infrared targeting of multiple hypersonic missiles is easier said than done. The missile you're hitting them with is going to be heating up the air around the camera probably at the same temps as the missile it's intercepting, and a base station wouldn't have enough resolution to guide a missile accurately from 100+km away while being alert for other missiles.

Sure hypersonic missiles will be detectible by infrared sensors. But those sensors have limited range, narrow field of view, and don't work well through clouds. And IR sensors can't give precise range data so they're less useful for targeting interceptors.

Isn't the point of these weapons that even if you can detect them they are too fast to intercept?

Unless you're trying to go to space, there really isn't much reason to go this fast in the first place. Even relatively modest supersonic passenger flight has proven to be a commercial failure (good luck to Boom Tech inc... you guys will need it.)

If you're going to space, an SSTO with scramjets would be interesting. But I think if SpaceX's reusable Starship succeeds without that tech, it would be hard to justify the additional complexity and expense of an SSTO built with a class of engine which hardly exists at all right now.

Check out Hermeus, working on building a reusable hypersonic aircraft. The engine they're using is a proprietary TBCC engine based on the GE J85.

SpaceX Starship will do this and be fully reusable. Starship can fly long distance with a reusable booster and somewhat shorter distances without a booster.

Granted, its not really 'flying' but it does reach the speed needed.

I believe the descendant of HOTOL is intended to bridge that gap... https://www.reactionengines.co.uk/

Blackbird does 3.75 designed maximum on turbo-ramjet I think?

> The SR-71 could make Mach 3 on its own but at incredible cost in fuel and complexity.

the SR-71 never struck me as "incredibly complex", the space shuttle however...

> Announcing breakthrough, surprising even, HAWC tech seems to clue in opponents about what sorts of countermeasures they'd want to start developing.

It's pretty hard to hide hypersonic devices these days, and the concept is not exactly a secret: Russia and China are testing devices, and multiple other countries are working on developing their own.

Hypersonics aren’t new tech, they were tested and developed decades ago by the US. It’s only recently that they’ve made a reappearance. Why do you think it took only 2 years for multiple military branches to spin up and test multiple separate missile designs? I would argue that Russia/China are playing the PR game in order for the US to appear behind in terms of missile technology.

There are offensive weapons that you advertise so that the enemy wastes resources to defend against.

Having nukes for MAD is useless if no one knows you have a credible threat.

Given the fact that other governments are fielding hypersonic scramjet missiles, I don't think so.

MAD worked out pretty well. Sometimes the best outcome of a weapon system is that it's never used.

Reminds me of the Doomsday Machine in Dr. Strangelove.

> The Whole Point of the Doomsday Machine is Lost if You Keep it a Secret!

> contributed to the USSR bankrupting itself trying to keep up with cold war tech?

Source?

For blunt-body spacecraft, ionization starts at around Mach 10. The aerodynamics of a missile will be different of course. Regardless, there is headroom above the Mach 5 hypersonic threshold before blackout occurs.

All actually deployed systems are nuclear capable, for them aiming is not a huge concern because the boom is very big.

What the US is playing at with their strictly conventional warheads is anyone's guess, the overall impression is a of a "we want that toy too!" program.

Seeker window design is a whole branch of missile engineering.

Most missles use a quartz window that is sprayed with an evaporative coolant. In more advanced designs the coolant flows through microchannels and then out micro holes on the leading edge, where the coolant evaporates and provides a film cooling.

https://www.spiedigitallibrary.org/conference-proceedings-of...

Ionization applies starting at a given frequency depending on heat. You have to reduce the heat around the radar or move the radar somewhere where the air is less hot. You also have to use a radar of a higher frequency.

I assume someone thought it sounds cooler and will help them recruit. It's an awful term, although maybe it will make it slightly harder for people to claim that the US military is a force for good because "our warfighters are global peacekeepers". Really highlights the absurdity.

> replaced the word "soldier" with "warfighter"

Technically, only the Army has soldiers. The non-exclusionary term used to be “men and women in uniform,” but that got tired, so I guess we get “warfighters” now.

It simply means that marines, sailors, etc get bent out of shape when you call them "soldiers." In their lingo, soldiers are in the Army.

In common parlance, a 'soldier' is anybody who is part of a military and an 'army' is any and all military. But I would not expect the Pentagon to be so casual with their use of terms relating directly to their affairs.

There's also been a major push to use the word "warrior". Not everyone is a fan.

See, eg: https://foreignpolicy.com/2021/04/19/united-states-afghanist...

Edit: As others have noted, "soldier" is traditionally a term reserved for members of an army. So for anything that cuts across the entire armed forces, you end up with soldiers, sailors, marines, airmen, coast guardsmen, and (of course) guardians (which is, I'm sad to say, the actual term for members of the Space Force). That's unworkably long (and it gets worse if you want to try and find gender neutral phrasing for "airmen" and "coast guardmen"; "airmen, airwomen, coast guardsmen, coast guardwomen" is even more ridiculously unworkable, and "airperson" is just too dumb to contemplate). I think the only reasonable answer is "serviceperson" or "servicemen and servicewomen", but I can't fault people for disliking those. But "warrior", as the article notes, already has incompatible meanings, and "warfighter" isn't much better.

Maybe the real answer is just to adopt the Space Force term for the entire armed forces, and call everyone guardians. (And it kills me that this is, actually, one the better ideas I've heard.)

Well for one US citizens might have to quarter warfighters.

At least for DARPA this change was well established even 26 years ago. It’s a way to be more inclusive of various roles within the military.