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DARPA's hypersonic scramjet achieves successful flight

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Re: DARPA's hypersonic scramjet achieves successful flight

#171

Post by margalabargala »

pageandrew wrote: post #151
speedybird wrote: post #97

Earlier quoted context omitted.

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.

The common parlance is just wrong. Soldiers do not serve on ships

Language and vernacular are fluid and things can become new things.

The people who serve on ships can become soldiers by consensus.

Re: DARPA's hypersonic scramjet achieves successful flight

#172

Post by speedybird »

anaganisk wrote: post #166
wongarsu wrote: post #158

Earlier quoted context omitted.

We tried with the British-French Concorde, the US Boeing 2707, and the Russian Tupolev Tu-144. That's three tries (or maybe two, the Boeing version was cancelled before prototype completion). Maybe we can do better today with the lessons learnt and the advances in material science since then. There's several startups banking on that. But so far commercial supersonic flight has only worked out as prestige projects, no…

Wasn’t TU-144 just a pissing contest entry with retrofitted engines of another aircraft? And Boeing 2707 quickly scrapped? Only Concorde ever saw the light of commercial operations. It was truly limited by its technology, of that date. And post 9/11 situation sealed its fate, its had one fatality in 20 years, its already better than 747 max by that metric. There is no point in saying Supersonic is impossible, things…

> Wasn’t TU-144 just a pissing contest entry with retrofitted engines of another aircraft?

Pissing contest, maybe, but the Tu-144 was its own aircraft. The airframe was designed from day one to be exactly what it was, a supersonic airliner (and contrary to popular myth, the design was not simply stolen from the Concorde although maybe the premise was..) I'm not sure if the original Tu-144 engines, the NK-144's, were originally intended for another plane, but as far as I know the only planes they were ever put in were the Tu-144. They were later replaced by RD-36 engines, which were designed for the Tu-144.

And let's not forget the Concorde's engines had a military background. They were derived from engines originally meant for the [cancelled] TSR-2.

The major problem I see for Boom is social. Environmental and class/economic concerns particularly; see the public backlash against Jeff Bezos' rocket hop for instance. Not to mention, the little experiment we've been running for the past ~2 years with remote work and teleconferencing has probably reduced demand for high speed business travel.

Re: DARPA's hypersonic scramjet achieves successful flight

#173

Post by Lazare »

corndoge wrote: post #87

Is it just me or has the Pentagon and the complex largely replaced the word "soldier" with "warfighter"? Feel like I've seen it a lot lately and I'm not sure what the change implies

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.)

Re: DARPA's hypersonic scramjet achieves successful flight

#174

Post by laurencerowe »

pageandrew wrote: post #151
speedybird wrote: post #97

Earlier quoted context omitted.

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.

The common parlance is just wrong. Soldiers do not serve on ships

But Navy personnel were deployed to Iraq and landlocked Afghanistan so clearly the DoD doesn’t see the clear delineation.

Re: DARPA's hypersonic scramjet achieves successful flight

#175

Post by mabbo »

rsj_hn wrote: post #135
burkaman wrote: post #111

Earlier quoted context omitted.

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.

It is politicians that keep insisting the job of the army is to get Afghanis to read and adopt liberal values. Peacekeeping is not popular in the army, for good reason. They are there to fight wars, not deliver social programs, build nations, or referee conflicts. If using language like "warfighter" can get the politicians to lay off on using the army for things other than fighting wars, then the clumsiness of the ph…

There ought to be a branch of the military that is dedicated to those goals.

I can imagine there are a lot of people who might be interested in that, but not in the war fighting. Today those people either don't enlist, or enlist and hate that aspect.

Re: DARPA's hypersonic scramjet achieves successful flight

#176

Post by T-A »

allenrb wrote: post #12

For a moment, reading only the first paragraph, I was hopeful that the problem of accelerating from subsonic to hypersonic had been solved. Alas, further down it makes clear that a booster was involved. Presumably a small solid rocket that accelerates to Mach 3-5(?) prior to scramjet ignition. Fine for a weapons system but will never be useful as transportation. Is anyone aware of progress toward being able to reach…

https://en.wikipedia.org/wiki/SABRE_(rocket_engine)

Re: DARPA's hypersonic scramjet achieves successful flight

#177

Post by chasd00 »

Isn’t the point of these you can launch them from Kansas while at the office and they still reach their target in a matter of minutes? No huge deployment required to get a missile boat in range, just load in the coordinates, press the btn, and go back to lunch.

Re: DARPA's hypersonic scramjet achieves successful flight

#178

Post by moralestapia »

pengaru wrote: post #165
moralestapia wrote: post #148

Earlier quoted context omitted.

>Operational complexity is orthogonal, and tends to be inversely proportional to simplicity in implementation ... I'm not sure what your point is with this. All complexity is operational complexity.

> All complexity is operational complexity. Uh, what? Example to illustrate the difference: Automatic transmission in an automobile, operationally simpler than the manual constant-mesh trans it broadly replaced: Driver (AKA the Operator) selects drive or reverse when stationary, no need to participate in gear changing while in motion. Substantially more complex in implementation in exchange; go look at the hydraulic…

Oh I see it now, you mean at the time of operation by the end-user.

I was thinking about the operational complexity of developing/manufacturing such thing, hence why for me it seemed to be virtually the same thing.

Thanks for taking your time to clarify this.

Re: DARPA's hypersonic scramjet achieves successful flight

#180

Post by nradov »

jhgb wrote: post #78

> The HAWC vehicle operates best in oxygen-rich atmosphere, where speed and maneuverability make it difficult to detect in a timely way. I'm reasonably sure that the infrared trace of a hypersonic vehicle doesn't make it difficult to detect. Likewise existing approaches to radar stealth are hard to reconcile with hypersonic speeds, which doesn't help avoid radar detection either.

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.
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