Are Aerospike Engines Better Than Traditional Rocket Engines?
everydayastronaut.com
everydayastronaut.com
> But all in all, I think the best way I can summarize the Aerospike is to compare it to like the rotary engine seen on cars like the Mazda RX-7 and RX-8 and their predecessors.
This is a great analogy.
Fun to see how interested Elon is with the engineering of rockets, looks like he could talk for days if he had the time.
Still 'wrong' though.
So while science moves on, engineering does not care about the 15th decimal place. Which is why we keep getting value from approximations.
The science on a heliocentric solar system is settled. The science establishing a link between anthropogenic carbon emissions and average global temperatures is also settled - built on foundational chemistry and physics, supplemented with observational evidence here on Earth, and validated by the planetary science done to understand Venus's temperature.
Sure, there's a lot of remaining uncertainty about short term effects, but mostly in the category of "just how bad is it likely to get?"
https://cei.org/blog/wrong-again-50-years-failed-eco-pocalyp...
https://cei.org/blog/manufacturing-alarm-dana-nuccitellis-cr...
https://wattsupwiththat.com/2017/10/30/some-failed-climate-p...
Just look at all the other child comments, most of them immediately jumped to the defence of supposedly irrefutable climate models. The reason climate deniers have so much support is that climate scientists, their communicators and their advocates have little credibility outside the true believers. If you don’t want to take my word on it, here’s a Stanford study on this exact topic:
https://www.sciencedaily.com/releases/2019/10/191018112145.h...
I'm actually kind of impressed.
Computer climate models have trouble returning accurate predictions for exactly the same reasons it’s hard to make accurate weather forecasts. They’re attempting to do things on the edge what we know is possible. Personally, I would not call that “flimsy as hell.”
The interview is great, and it really highlights the difference in the way that founders and engineers think compared to those in the finance and commercial fields. If this was an investor interview, they'd be asking about deadlines and revenue projections. If it was a Joe Rogan interview, the questions would be vague questions about social, political, or philosophical repercussions. Those are all important questions, but they don't actually address what any business or organization is really trying to do. You can learn a lot more about a person or organization by speaking their language and letting them talk the way they are comfortable than by stuffing them into your own rubric of what they should be expected to say.
This video has been in the works for many months and knowing his work it is probably one of the most comprehensive works on aerospike engines outside of academia.
As someone who does have some training in it, I can say that "best space content on YouTube" is akin to "best brain surgeon in a room full of circus clowns."
He gets a lot of stuff right, don't get me wrong. But the appearance of credibility is down to enthusiasm, specialty of focus, and editing and delivery. It's fine as far as it goes, but it's infotainment. It's more important that you be entertained and feel smart than sit down and struggle with the actual application of engineering principles and achieve any kind of reliable knowledge.
(Scott Manley wins at all three, though.)
Taking an esoteric concept and making it understandable for the masses takes far more talent and dedication than you might think, and it's something that experts often fail at (or don't attempt). This guy makes no false claims about his credentials or the intended purpose of his videos, and your condescending gatekeeping shows a real lack of understanding for what this guy is actually doing and why it's so valuable.
Long ago, some cranky academic wrote on his very well-sourced and specialized website, back when there was still that sort of thing, something like, "Everybody said that the internet was going to let anybody say anything at all. It turns out they were right."
I'm fine with the backlash from what you call my "gatekeeping." (I imagine that some gates need to be kept, but I suppose that's another story.) My point is that "the best on YouTube" is not as grand a qualification as one might suspect, and is certainly not a guarantee of accuracy.
You could've compared this to a brain surgeon among medical students, or even software engineers, something technical/noncreative.
Would you care to give a few examples so that I can appreciate their significance? Are they major errors or are you nitpicking?
These two are perfectly legitimate ways of using the medium of video to avoid making mistakes.
Agreed, Everyday Astronaut and Scott Manley are my go to for space and rocket news and videos.
Anybody else interested in space stuff should also check out Scott Manley. I also like Marcus House also has some really great stuff.
These guys focus a lot on SpaceX but they also do a lot of other videos on general space stuff.
Marcus House: https://www.youtube.com/channel/UCBNHHEoiSF8pcLgqLKVugOw
Scott Manley: https://www.youtube.com/user/szyzyg
I know I've lost this one among popular and lay audiences. It's just way too cool to say 'aerospike.'
Or is the matter whether or not the truncation has aerodynamic effects? (Do any truncations not?)
http://www.astronautix.com/g/garveyaerospike.html
During 2005, GSC and California State University, Long Beach (CSULB) conducted several notable small launch vehicle R&D activities through their partnership in the California Launch Vehicle Education Initiative. Using a single-chamber, liquid-propellant, annular aerospike engine concept developed by CSULB, the GSC/CSULB team validated the basic design and ignition sequence with a successful static fire test at the Reaction Research Society's Mojave Test Area (MTA) in June 2003. The team then mounted one of these 4,444-newton thrust LOX/ ethanol ablative engines onto their Prospector 2 vehicle and proceeded to conduct the first-ever powered liquid-propellant aerospike flight test at the MTA in September 2003. In response to several issues observed during that flight, modifications were made to the engine fabrication process. Another flight test with the Prospector 4 vehicle followed in December 2003. Performance was entirely nominal, resulting in complete recovery of the vehicle and key trajectory data.
http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.544...
But it’s good to learn why certain technologies don’t work and why they haven’t taken off. There is definitely something to learn from failures as much as to learn from optimal designs.
Overall, I applaud the author for this amazing video.
Both of those have solutions: natural circulation, and turbo-electric drive. Natural circulation is seen on the Ohio class submarines[0], in which the heat gradient inside the reactor is enough to cause it to circulate without powering a pump to move it around. It only works well at low power, but if you're trying to make a good imitation of a hole in the water, that's enough. And it's not like the Gotland-class is any better at going fast.
Turbo-electric propulsion was seen on the USS Tullibee[1]. It definitely was an advantage, in terms of making the submarine quieter. But it had a disadvantage in being heavier than the machinery required for geared drive.
And the USN wants nuclear submarines. A Gotland had a pair of 75kW generators onboard for power/propulsion. A S9G reactor drives a 30MW pumpjet on a Virginia class. SSNs can go faster when necessary, and have more power available to run all their systems.
[0] https://en.wikipedia.org/wiki/S8G_reactor [1] https://en.wikipedia.org/wiki/USS_Tullibee_(SSN-597)
That sounds boring to me - there's no room for improvement. The aerospike and wenkel engines and ramjets are exciting exactly because they have not been explored so well and there may be a lot of improvements yet to be discovered.
However, the atmospheric pressure in Mars is a lot lower than on earth, which means the same diameter scale issues don't apply.
I think Starship is intended to go SSTE (Single Stage to Earth) from Mars, for instance.
This summer I read H&H and RPE as well as reading some papers and talking to rocket engineers, and this is the best article on aerospikes at a high level that I've read.
That's a rare talent.
I remember EverydayAstronaut had a chat with Elon Musk about aerospikes recently, don't know if it was featured in the video.
Aerospikes have more surface area, which means more area to cool... which is more area for the propellant to flow through to get heated up to run the engine, which means more power available to give more fuel.