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DARPA's hypersonic scramjet achieves successful flight

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Re: DARPA's hypersonic scramjet achieves successful flight

#191

Post by qaq »

sudosysgen wrote: post #125
qaq wrote: post #45

Earlier quoted context omitted.

They were not a major portion of Nuclear Weapons R&D and manufacturing were done in Ukraine including design and manufacture of majority of electronics including guidance systems, comms etc. as well as most top tear weapons were designed by Yuzhnoye Design Office (Dnepr Ukraine) and manufactured by Yuzhny Machine-Building Plant (Dnepr Ukraine)

Ukraine indeed had a lot of manufacturing and design of nuclear weapons. Even then the control, launch and timings were all centralized in Moscow. They would have had to reverse engineer and hack a lot of it amidst attacks from Russia and perhaps even the US.

I think you are still confused the control systems were designed and manufactured in Ukraine there was nothing to reverse eng. The only step not done in Ukraine was uranium enrichment.

Re: DARPA's hypersonic scramjet achieves successful flight

#192

Post by jacquesm »

speedybird wrote: post #80
pengaru wrote: post #70

Earlier quoted context omitted.

And the SR-71 is so simple the complexity falls off a cliff at the engine, hence your inclination to only care about that in comparing the two. The space shuttle is like a reusable mobile space station, airlocks and all. Occupants of the SR-71 wore space suits the entire time, there's a lot of minimalism on display in the SR-71 which is a large part of what makes it so glorious.

You seem to be suggesting but not outright saying something that is a misconception: The SR-71 did in fact have a pressurized cockpit, which was also air conditioned as well (it had to be, because the aircraft would cook the crew otherwise.) The SR-71 was sophisticated in other ways as well; for instance in having ejection seats. In fact the first four shuttle flights (all Columbia) had ejection seats too and guess w…

I think the two of you are largely in agreement, but GP rightly points out that the SR-71 was less complex than it could have been and that this is in party why it was so successful. The ability to leave stuff out in engineering exercises can lead to substantial benefits and that's worth noticing.

Re: DARPA's hypersonic scramjet achieves successful flight

#193

Post by shadilay »

sudosysgen wrote: post #128
jhgb wrote: post #120

Earlier quoted context omitted.

> they are preparing for mass production of hypersonic air breathing missiles ...or so they say. Of course they've been preparing for mass production of T-14 and Su-57 for quite some time now. Any day now they'll get them, I'm sure...

T-14 is ready for mass production, it's just too expensive for the broke Russian government to buy enough of them. 3M22 unlike Su-57 has actually achieved it's goals. It has already been fired from ships and hit targets while achieving it's speed and altitude goals. Su-57 has not been able to achieve it's goals of being stealthy or being reliable so there is no reason it would be readied for mass production.

If I remember correctly it was claimed that the Su57 was too good and that's why they we're cancelling serial production.

Re: DARPA's hypersonic scramjet achieves successful flight

#194

Post by sandworm101 »

jhgb wrote: post #134
sudosysgen wrote: post #123

Earlier quoted context omitted.

Interception against an actively manoeuvring target is a question of kinetic energy. If the intecepting missile is smaller all the hypersonic missile has to do is zig-zagging randomly and you're toast. If you're going to wait for the hypersonic missile to be close enough that this isn't a problem, you have the issue that your missile won't be able to manoeuvre right and might still be building up velocity. Plus there…

> Interception against an actively manoeuvring target is a question of kinetic energy. If the intecepting missile is smaller all the hypersonic missile has to do is zig-zagging randomly and you're toast. What you're describing is not a matter of kinetic energy (clearly if it were about kinetic energy, this would be defeated by making the interceptor weigh 30 tonnes) but a matter of transverse acceleration. On that ma…

>> It would seem that the easiest way to distinguish a flare would be to look if it's in a controlled flight?

"This isn't one of your church picnic flare gun firings". Smarter people than Homer have been working on flare technology for 40+ years.

(2003) https://www.nationaldefensemagazine.org/articles/2003/11/30/...

>> Also, due to low L/D ratio in the high Mach region, if your missile is zig-zagging randomly, it won't stay fast for long.

These are not airplanes with wings. These are missiles very high in the atmosphere flying complex flight paths more accurately describes as trajectories. The air is thin, the drag low, the energies extraordinarily high. A successful zig-zag maneuver could be as small as one degree left or right, up or down. And sacrificing speed to escape an interceptor is a valid tradeoff considering that, not being an airplane, the missile intends to slam into the ground/target in a minute or two no matter what its speed.

Re: DARPA's hypersonic scramjet achieves successful flight

#195

Post by shadilay »

WhisperingShiba wrote: post #122
merpnderp wrote: post #74

Earlier quoted context omitted.

How did the US fuck over Russia in WWII? And are you aware of the billions of foreign aid many countries get from the US which is tied to issues like human rights, freedom, and democracy?

The US let the Russians break themselves fighting the Eastern front while they invaded north Africa. The North African front was basically secure while Stalingrad was happening, and if the US applied more pressure to Germany in this period, as the Russian requested, the Germans probably would not have done so much population damage to Russia. Bitterness of this fueled a lot of ideological tensions. I was also taught…

Without Lend Lease keeping the Russians supplied with food/logistics they would have starved and collapsed.

Re: DARPA's hypersonic scramjet achieves successful flight

#196

Post by sandworm101 »

>> released from an aircraft seconds before its Northrop Grumman scramjet (supersonic combustion ramjet) engine kicked on.

No. The scramjet would only work at supersonic speeds. The missile was boosted to speed/altitude by another conventional rocket before lighting the scramjet.

>> The HAWC vehicle operates best in oxygen-rich atmosphere

As opposed to a oxygen-poor atmosphere? Mars? Venus? And "best" suggests that this missile might operate poorly, but operate nevertheless, in some other non-oxygen place. Maybe this thing also travels through space. We may be going to war on Venus after all.

Re: DARPA's hypersonic scramjet achieves successful flight

#197

Post by EdwardDiego »

speedybird wrote: post #97
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

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.

Huh, in my country, we just say "personnel". Covers all genders, all branches, and territorials (our version of the National Guard, I guess) as well as the regular force.

Re: DARPA's hypersonic scramjet achieves successful flight

#198

Post by nurgasemetey »

JumpCrisscross wrote: post #121
jhgb wrote: post #118

Earlier quoted context omitted.

But maneuvering at high velocities won't be that easy. As far as I understand it, your lift/drag ratio decreases appreciably with increasing Mach numbers. So either you'd have to limit your maneuvering, or you'd have to have a propulsion unit with ridiculous amounts of thrust - at a situation when any amount of useful thrust is hard to obtain, since we still don't know really well how to do propulsion in this regime.

As a former aerospace engineer, I’m sceptical of the strategic value of hypersonics. Tactical? Sure. They’d have a better chance of taking out SAMs, light radar, et cetera . But the talk about these being carrier killers is, based on everything we’ve seen, off the mark. (Spending the cost of one hypersonic on a swarming attack would probably do more damage.)

I think taking out SAMs is huge thing. Or I am wrong?

Re: DARPA's hypersonic scramjet achieves successful flight

#200

Post by liamwire »

sandworm101 wrote: post #196

>> released from an aircraft seconds before its Northrop Grumman scramjet (supersonic combustion ramjet) engine kicked on. No. The scramjet would only work at supersonic speeds. The missile was boosted to speed/altitude by another conventional rocket before lighting the scramjet. >> The HAWC vehicle operates best in oxygen-rich atmosphere As opposed to a oxygen-poor atmosphere? Mars? Venus? And "best" suggests that t…

> As opposed to a oxygen-poor atmosphere?

My interpretation of that sentence is that it performs better at lower altitudes, where the density of oxygen (and the other atmospheric gases as a whole) is higher.

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