DARPA's hypersonic scramjet achieves successful flight • Hacker News Board

Re: DARPA's hypersonic scramjet achieves successful flight

#61

Post by WhisperingShiba » Sun, Oct 03, 2021, 7:47 PM UTC

qaq wrote: post #21

Ericson2314 wrote: post #17

Earlier quoted context omitted.

That's a straw man. The problem is tons of research and development won't happen without the state, but the main avenue the state funds development (as opposed to research) is the military. There are many possible futures, and the world is highly non-ergodic, so there is a real cost here to biasing the development of technology in this matter. "Opportunity cost" doesn't do the concept justice. We don't have to stop m…

Well could you point to the downside of this? From teflon to internet and countless other things you use every day that came out of DARPA and other def. research, what would have changed if it was funded via different model?

One prominent one is that we use fear to control other countries instead of love.

We spend so much human talent on defense, and sure we got a bunch of great technologies, but who's to say that we wouldn't have got them through some other avenue, later? Or perhaps even better technologies. I only speculate about the former, but I am quite certain a lot of the violence in the world has been caused by American Neo-colonialism and the terrorism we imposed upon the world. I am a betting man, and I bet that if we didn't fuck the Russians over so hard in WW2, that we wouldn't have had the cold war.

Re: DARPA's hypersonic scramjet achieves successful flight

#62

Post by imglorp » Sun, Oct 03, 2021, 7:47 PM UTC

Iv wrote: post #37

doovd wrote: post #5

Earlier quoted context omitted.

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

It is probably a reference to the SDI program, also called the Starwars program. Note that the economic impact on USSR is just speculation. https://en.m.wikipedia.org/wiki/Strategic_Defense_Initiative...

Yes, and yes that remark was speculative.

Re: DARPA's hypersonic scramjet achieves successful flight

#63

Post by thawcixr4R » Sun, Oct 03, 2021, 8:02 PM UTC

JumpCrisscross wrote: post #57

xvilka wrote: post #38

Earlier quoted context omitted.

There are also IARPA[1] and ARPA-E[2] (and few others as well). ARPA-E is more "peaceful" agency. [1] https://www.iarpa.gov/index.php/research-programs [2] https://arpa-e.energy.gov/

Have they produced any breakthroughs?

IARPA has produced quite a few:

- https://arstechnica.com/science/2010/12/sciences-breakthroug...

- https://web.archive.org/web/20160312133713/http://www.deltek...

- https://www.scientificamerican.com/article/the-u-s-governmen...

Those are just recent, unclassified ones.

ARPA-E being the "peaceful industry" is a lot more open about private partnerships and generally just funds and provides oversight: https://web.archive.org/web/20100527161846/http://www.energy...

Some renewable fuel projects: https://arpa-e.energy.gov/news-and-media/blog-posts/refuelin...

They're focused on renewables, lessening waste, etc. and have made some contributions in that space, just not as sexy as "borgsects" and "space lasers" like DARPA or advancing nation state surveillance and electronic warfare capabilities like IARPA.

Everything is starting to get an ARPA though because of how it's somewhat allowed to cut through red tape for innovation which is hard for usgov: https://www.nature.com/articles/d41586-021-01878-z

Re: DARPA's hypersonic scramjet achieves successful flight

#64

Post by newsclues » Sun, Oct 03, 2021, 8:02 PM UTC

imglorp wrote: post #4

I'm curious about the PR strategies at play when governments either saber-rattle or keep secrets. Announcing breakthrough, surprising even, HAWC tech seems to clue in opponents about what sorts of countermeasures they'd want to start developing. By contrast, the US has held the high-altitude Aurora/SR-72/whatever tech very close to the vest for decades, when it's pretty much obvious that a new generation of high alti…

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.

Re: DARPA's hypersonic scramjet achieves successful flight

#65

Post by patagurbon » Sun, Oct 03, 2021, 8:03 PM UTC

amelius wrote: post #6

US's answer to Russia's Zircon missile? https://www.military.com/equipment/weapons/why-russias-hyper... > U.S. Aegis missile interceptor systems require 8-10 seconds of reaction time to intercept incoming attacks. In those 8-10 seconds, the Russian Zircon missiles will already have traveled 20 kilometers, and the interceptor missiles do not fly fast enough to catch up.

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.

Re: DARPA's hypersonic scramjet achieves successful flight

#66

Post by moffkalast » Sun, Oct 03, 2021, 8:04 PM UTC

dylan604 wrote: post #55

"Goals of the mission were: vehicle integration and release sequence, safe separation from the launch aircraft, booster ignition and boost, booster separation and engine ignition, and cruise. All primary test objectives were met." When the booster separation occurs, what happens to that booster? Does it self destruct on the way back down? Would any part of it be recoverable by inquisitive minds? Is booster tech so ru…

These absurd speeds result in a significant amount of aerodynamic heating, so assuming the booster is simply not shielded much it'll likely disintegrate in seconds after being detached and no longer in the missile's shadow.

Re: DARPA's hypersonic scramjet achieves successful flight

#67

Post by BobbyJo » Sun, Oct 03, 2021, 8:14 PM UTC

jackschultz wrote: post #2

DARPA has such a list of impressive, world wide useful technologies that wouldn't have been able to be created without funding from the government at the time given the time and money and at time, unlikeliness to be successful [0]. It really sucks that there's a 'D' for 'Defense' at the front of the acronym. Their website says they're "creating breakthrough technologies and capabilities for national security". Horrib…

Not to be a Debbie Downer, but functional Scramjet technology does very little for humanity outside of defense. As is the case with most of what DARPA funds, no? If that wasn't the case, then the market itself would be chasing the technology. Like, what would this be useful for?

I guess I'm just fundamentally questioning what you mean when you say 'human progress'. I assume you mean it more in terms of improvement as opposed to preservation, but given the fact that life itself is a struggle against entropy on all levels, preservation is a very important foundation on which to build.

Re: DARPA's hypersonic scramjet achieves successful flight

#68

Post by nradov » Sun, Oct 03, 2021, 8:18 PM UTC

throwaway210222 wrote: post #50

nradov wrote: post #48

Earlier quoted context omitted.

"Europe" is probably the wrong term here. The USA's efforts to stop Russia from antagonizing NATO members probably rates 8/10. Part of Russia is also in Europe.

No, no. Ukraine paid the 'entry price' that was asked of them to be protected by USA, (and France, UK, Russia, China) by surrendering their nuclear weapons. This was a level of vulnerability and trust in third parties the good citizens of USA (and the others above) would never for a second countenance. The USA (and the others) willingly signed up to the deal [1]. And then failed to do any deterring when it was time t…

That was a non-binding memo. If Ukraine wanted protection then they should have insisted on a mutual defense and non-aggression treaty.

Re: DARPA's hypersonic scramjet achieves successful flight

#69

Post by soverance » Sun, Oct 03, 2021, 8:22 PM UTC

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…

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.

Re: DARPA's hypersonic scramjet achieves successful flight

#70

Post by pengaru » Sun, Oct 03, 2021, 8:33 PM UTC

sonofhans wrote: post #28

pengaru wrote: post #16

Earlier quoted context omitted.

> 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...

The J58 powering the SR-71 is still one of the most complex engines ever built. The space shuttle is a simple rocket by comparison. https://en.wikipedia.org/wiki/Pratt_%26_Whitney_J58

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.