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NASA validates revolutionary propulsion design for deep space missions
- cs702 4y agoIt reads, sounds, and looks really cool. We live in interesting times.
- Washuu 4y agoI lived next to the testing range for this engine for the past few years. It sounds amazing from a far too. The shock diamonds it creates have an audible rumble/rhythm to it.
- vanattab 4y agoIn the theoretical limit how much improvement in efficiency could such engines provide?
- deleted 4y ago[deleted]
- mdorazio 4y agoUp to 25% improvement compared to conventional rocket engines according to the Wikipedia page. I haven’t found an actual ISP measurement for this NASA engine, though.
- messe 4y agoIs that a 25% improvement in ISP/exhaust velocity or another metric?
- drtgh 4y agoIt seems that 25% paragraph on wikipedia cites a non-technical article[1] from 2018: "Theoretical calculations have shown that detonation combustion is 25% more efficient than the isobaric combustion cycle, which corresponds to constant-pressure combustion, which is implemented in the chambers of of modern liquid propulsion engines." From another article[2] of the same year: "Conservatively speaking, a rotating detonation combustor, or RDC, should reduce specific fuel consumption by about 5% compared to a conventional engine. This measure of fuel efficiency is calculated by dividing fuel consumption by power output. A rotating detonation engine generates more power, which drives down specific fuel consumption. A reduction on the order of 5 percent would be a breakthrough, given that designers of conventional engines “try to eke out fractions of a percent,” says Scott Claflin, director of advanced concepts at the Rocket Shop, Aerojet Rocketdyne’s innovation organization." [1] https://rg.ru/2018/01/18/levochkin-vozmozhnost-sozdaniia-detonacionnogo-dvigatelia-podtverdilas.html https://rg.ru/2018/01/18/levochkin-vozmozhnost-sozdaniia-det... [2] https://aerospaceamerica.aiaa.org/departments/increasing-engine-efficiency/ https://aerospaceamerica.aiaa.org/departments/increasing-eng...
- wolverine876 4y ago> that 25% paragraph on wikipedia cites a non-technical article[1] from 2018 The article you footnoted is also in Cyrillic. After all this time, it's amazing to see people trust Wikipedia. It's like they don't care if it's true or not; it's entertainment, pretending to know, not knowledge. A perfect way to spin your wheels forever and go nowhere.
- messe 4y ago> The article you footnoted is also in Cyrillic. And your comment is in Latin, going by your terminology. In the age of decent online translators, do you care to elaborate on why that’s a problem?
- bobthepanda 4y agoI mean, Russia has a fairly large space program, is that surprising?
- kossTKR 4y ago25% sounds super disappointing from a laymans perspective and not very "revolutionary" in the grand scheme of time and space. Can't wait until AI will be able to iterate advanced engineering designs in simulation space at incredible speed.
- grogenaut 4y agoFrom 10% to 35% is a 25% improvement, you're still at 35%... From 70 to 95% is a 25% improvement, but it's a lot more. Going from 98 to 99% is only 1% but also like really a 10x improvment. Rockets are operating at pretty decent efficiency, 25% improvment on an internal combusion engine would be mind blowing and make EVs way less interetsting. There are theoretical maximum efficencies for various types of engines due to thermodynamics. You always lose energy to heat. Entropy is a b**.
- Lichtso 4y agoTechnically, from 10% of something to 35% of something is a 350% improvement or a 25 percent point improvement. https://en.wikipedia.org/wiki/Percentage_point https://en.wikipedia.org/wiki/Percentage_point
- dotancohen 4y agoActually, from 10% of something to 35% of something is a 250% improvement. You already had the first 10%.
- grogenaut 4y agoyes but people often conflate/confuse that... saying the delta in %'s... not % improvement. I agree with you, I'm attempting to point out how a small % increase is a huge actual improvement. This GP was saying that a 25% improvment in the efficiency of a rocket engine was not much to a layman.
- dotnet00 4y agoSimulations aren't really the limiter on engine efficiency, SpaceX etc already lean heavily on simulations. The limiters on engine efficiency at this point are mostly materials and costs, and even the latter are coming down with better fuels (eg Methane, which is extremely popular with rockets debuting this decade) and different design philosophies (eg SpaceX's Raptor engine, which is supposedly under $1M per engine while being the most advanced flight tested rocket engine out there).
- deleted 4y ago[deleted]
- out_of_protocol 4y agoAnybody know what Specific impulse we are talking about? According to wikipedia, current values for rockets are around 300s
- sounds 4y agoThis was a smaller prototype. Unless they release a theoretical Isp model for scaling up the engine (which, would we believe them if they did?) we can't know for certain yet.
- phkahler 4y agoNot sure the relationship, but they say 600PSI chamber pressure, or about 20 bar. Spacex is push 200 to 300 bar pressures. I would think this means they're currently at a low ISP. The challenge with RDEs has been keeping them lit, I e. Keeping the detonation wave going indefinitely. Once that's done they can work of efficiency. Seems like they're at that point now.
- wolfram74 4y agoPressure can tell you about thrust, but I don't think its as strongly linked to specific impulse. However looking at the wiki article on the RS25 which is pretty high up there being a hydrolox engine, I see it's also got a chamber pressure in the 200+ bar range.
- sacnoradhq 4y agoAt first, I thought it was an insanely scaled ion drive and then maybe a toroidal aerospike. Nope, no grids and there's water. Holy damn.
- dotnet00 4y agoScott Manley did a video on Rotating Detonation Engines a few years ago https://m.youtube.com/watch?v=rG_Eh0J_4_s https://m.youtube.com/watch?v=rG_Eh0J_4_s
- downvotetruth 4y agoReal Engineering's video today likely causing resurfacing from Jan https://www.youtube.com/watch?v=RVxgyz_avQM https://www.youtube.com/watch?v=RVxgyz_avQM
- fbdab103 4y agoI was greatly annoyed to see the jet color scheme used in nearly all of those visualizations. We have better options!
- boringuser2 4y agoWhat's up with all of these crazy technical developments after a period of relative stagnation? Aside from it being merely random or selection bias, it's plausible that there's some kind of AI assist beyond what we know happening behind the scenes.
- twic 4y agoPeople have been working on rotating detonation engines, and making steady progress, for years. The idea dates to the '60s, but i think work really picked up about a decade ago.
- redeeman 4y agoi dont think thats plausible? we do not have AI
- boringuser2 4y ago[flagged]
- PartiallyTyped 4y agoI said a few days ago that it is very likely 3 letter agencies and other organisations have had GPT4 equivalent models for some time now. It doesn’t seem that unlikely that some branches of the US gov would have much more advanced models.
- boringuser2 4y agoYou're right, it kind of makes me think AGI won't come about from LLMs.
- feanaro 4y agoWhy do people always say this? It's almost like a thought-terminating cliche. Thousands of companies competing with each other were not able to do it earlier, but the NSA always has better everything, by definition.
- robotfelix 4y ago> to deep space destinations, such as the Moon I feel woefully underqualified to call out NASA's PR team, but I don't _think_ the Moon qualifies for most definitions of "deep space". Exciting news all the same, and I can only assume they meant to suggest that RDRE propulsion is useful for destinations that are nearer too!
- akiselev 4y agoFrom the NASA Deep Space Communications Educator guide [1]: > Deep space begins at approximately 42,000 km (26,098 mi) from Earth [1] https://www.nasa.gov/sites/default/files/atoms/files/ps-03435_deepspacecomm-508.pdf https://www.nasa.gov/sites/default/files/atoms/files/ps-0343...
- mgsouth 4y agoThe U.S. government defines deep space as anything beyond low-earth orbit. [1] Others vary. [2] The U.S. "Deep Space Network" was created because communications with low-earth orbit and beyond-LEO had very different requirements [3]. [1] https://uscode.house.gov/view.xhtml?req=granuleid:USC-prelim-title51-section10101&num=0&edition=prelim https://uscode.house.gov/view.xhtml?req=granuleid:USC-prelim... [2] https://en.wikipedia.org/wiki/Outer_space#Regions_near_the_Earth https://en.wikipedia.org/wiki/Outer_space#Regions_near_the_E... [3] https://en.wikipedia.org/wiki/NASA_Deep_Space_Network#Deep_space https://en.wikipedia.org/wiki/NASA_Deep_Space_Network#Deep_s...
- deleted 4y ago[deleted]
- abudabi123 4y agoDeep space should be the furthest point reached by probes in likeness to deep ocean depth exploration. Voyager I, II and New Horizon probes should redefine the ”distance.“
- daveguy 4y agoI believe they call that interstellar space to distinguish from "deep" space.
- fbdab103 4y agoNASA should release a Kerbel Space Program mod with this engine.
- 1letterunixname 4y agoThe fuel and oxygen injectors use a variant of the Tesla Valve https://en.wikipedia.org/wiki/Tesla_valve https://en.wikipedia.org/wiki/Tesla_valve
- todd8 4y agoFascinating. I was just a kid in 1964 when I learned about fluidics. My December issue of Scientific American had an article on fluidics featured on the cover and I always wondered why there never seemed to be any applications of the devices described in that article. In particular, the use of fluidic logic gates and latches, etc.
- Taniwha 4y agoSo there's a rotating flame front going in one particular direction .... anyone know does it impart angular momentum to the thing it's propelling?
- rozal 4y agoThis is not revolutionary. Quantum propulsion is.
- hinkley 4y agoSomething that doubles rocket payload size is a huge deal.