NASA's report server is a national treasure, especially the material from the 50s and 60s that he references. Some of the most crisp and succinct technical writing you'll find, and you can infer a lot about how they ran projects. Declassified NRO reports are also very good - you can see the Lockheed Skunk Works principles in action. Example: https://www.nro.gov/Portals/135/documents/foia/declass/WS117...
mhh__ 2 days ago [-]
Lots of academic and engineering things from back then are great.
I have an incomplete set of the radlab textbooks. They're still useful even today, and have a really careful pace to them because they were written for a generation for whom electricity was still relatively new.
One of the things that is a real shame is just how artfully bound those old books are. Leather, thick but smooth paper, etc.
buescher 1 days ago [-]
The rad lab series basically set the program for electrical engineering ever since. I have a couple too. They are also available on archive.org.
duped 2 days ago [-]
If there's two things I've learned about chemistry from ExplosionsAndFire in YouTube it's
- Yellow is bad
- The 60s were awesome
dotancohen 2 days ago [-]
Just yesterday I pointed out a yellow flame to someone as evidence of incomplete combustion on the gas stove. Laughing I showed them your timely comment.
Out of context of the thread, your second point was amusingly interpreted to be about LSD.
duped 1 days ago [-]
I'm sure a lot of the chemists making things go boom in the 60s were also on LSD, for what it's worth
sr-latch 2 days ago [-]
and if you're ever writing 1DoF codes yourself, NASA's CEA for propellant chemistry calculations is freely available https://cearun.grc.nasa.gov/
LM358 1 days ago [-]
The executables and source code are sadly not freely available any more, allegedly for ITAR reasons.
In USSR/Russia we had a stand-up comedian (Zadornov) who in one of his jokes was explaining how the conciseness of the language is advantageous on the battlefiled.
Recently I had to write in Russian (my native language) a tech doc of many pages. That is after 26 years of tech writing only in English (my 2nd language). That experience resulted in an epiphany for me on why Russia is so technically behind as I suddenly understood what Zadornov was talking about :) In comparison to English, Russian sucks, to say the least, as a technical language. All the things which make Russian great for literature and poetry make it terribly inefficient for tech writing, miles and miles behind English. If anything, I think English is the secret sauce of the success of the Western technical civilization.
(For older Russian speakers - if you remember another Zadornov's "dolbani pljuhalkoj po kuvykalke, prikin'sja vetosh'ju i ne otsvechivaj" - now I think it really comes from the same weakness of Russian for technical communication)
z3phyr 2 days ago [-]
Th soviet mechanical and rf engineering efforts were very well regarded during the early cold war period, and I would argue, much more sophisticated. Language did not stop the USSR. It was the economic policy like banning some disciplines based on ideological grounds like cybernetics etc.
Check it out, the things for which a western scientist or engineer is given credit, were discovered/invented much earlier by soviet counterparts! What do you think about Kotelnikov?
Symmetry 1 days ago [-]
How much of it was ideological and how much of it was just that Gosplan didn't want computers taking their power, and so Gosplan cut funding to computer development?
myrmidon 2 days ago [-]
I consider the view "many discoveries were made much earlier by soviet counterparts" to be mostly incorrect and heavily biased.
But it is a common and easy trap for a lot of nationalities to fall into, because there are innumerable discoveries that happen before (and/or independent of) the canonical "inventor" (and you're automatically more likely to know the independent inventors if they come from your country!).
Regarding Kotelnikov specifically: You could make the same argument (re: discovery of sampling theorem) for Whittaker, who published in 1915; ultimately, though, the whole debate is mostly pointless.
I strongly believe that no single inventor so far was truly "significant", in that his nonexistence would have delayed science as a whole by more than a decade or two (consider Newton/Leibniz for calculus, Einstein/Poincaré/Hilbert for relativity, etc.).
People should not focus so much on WHO discovered a particular fact, because the cold truth is that it's mostly a personality cult and that any single scientist that ever existed, no matter how brilliant, was still replaceable (from a "human progress" kind of view). Which does not stop me from being a Fermi-fanboy.
But I completely agree with you that language did not really hinder USSR science.
randmeerkat 1 days ago [-]
> the cold truth is that it's mostly a personality cult and that any single scientist that ever existed, no matter how brilliant, was still replaceable
I found the MBA.
greedo 1 days ago [-]
Nah, it's really akin to the debate historians have over Great People or Inexorable events. Would calculus have been discovered had Liebniz and Newton died in a duel? Would the Panama Canal still have been built had Teddy Roosevelt not been its primary proponent? The Apollo project shows that Big Events can still happen even when it's most eloquent proponent gets a bullet to the head.
randmeerkat 23 hours ago [-]
> Apollo project shows that Big Events can still happen even when it's most eloquent proponent gets a bullet to the head.
If Sergei Korolev didn’t die suddenly and unexpectedly, the Soviets may have actually won the race to the moon. Their space program atrophied afterwards and struggled to succeed.
I really wonder at the modern obsession with associating people with cattle.
greedo 20 hours ago [-]
Cattle?
gregw2 3 hours ago [-]
I’m guessing this is a techie reference.
Computer servers can be divided into two roles in modern technical architectures… they are either “cattle” or “pets”. Pets are computer servers that have names and are always up. Cattle are servers that are transient, spun up and down as needed and do not necessarily have any long running identity/name as a component of a larger system.
The poster is making a critiques of how by treating historical persons contributors as cattle, we are considering them a dispensable, unnamed, a commodity that is easily replaced and interchangeable and missing their very real contribution, value, and humanity.
greedo 1 hours ago [-]
I thought also that he was making the docker/container reference, just didn't see how it applied. Thanks for your expansion.
I do find the Great Person theory and its critiques fascinating. I think of how Kennedy navigated the Cuban Missile Crisis and avoided nuclear war, then I think of how the sheer consensus of the US military after WW2 was to build a huge nuclear arsenal and use it any possible chance.
myrmidon 1 days ago [-]
> I found the MBA.
Nope, thats a false positive.
Also cutting the quote there heavily twists the meaning: I'm not saying those scientists were replaceable as persons, just that their effect on all of humanities scientific progress was.
Many persons have a strong notion that we owe certain discoveries to a specific person, but this does not even hold up to cursory examination in my view (those discoveries would have been made in short order by someone else).
I'm very curious though if you have counterexamples, or think the premise is otherwise flawed.
avmich 1 days ago [-]
> I'm very curious though if you have counterexamples, or think the premise is otherwise flawed.
I suspect we can find counterexamples if look enough, though to truly present some a serious knowledge of science history is needed.
What do you think of contributions of Srinivasa Ramanujan and George Cantor?
myrmidon 1 days ago [-]
I think some of Ramanujans results might have come significantly (more than a decade!) later without him, but I don't think that this would have held up mathematics as a field significantly.
For Cantor, I think the maximum delay in results would've been even less, but maybe the impact (=> set theory) bigger during that time?
I will concede that there is a lot of value that any specific scientist provides just from correspondence/communication alone which is very hard to quantify.
I also think if you took away whole institutions from a hypothetical timeline, like, e.g. the University of Göttingen, then the impact could be quite clear (more than just a decade of lost progress in some field). So maybe you could argue that some founders of prodigious institutions helped human science more than any single scientist? But this is highly hypothetical (if the people AT those institutions would have existed regardless). Also a distasteful thought (to me).
vbezhenar 2 days ago [-]
I'm Russian speaker and I don't really understand why do you think that Russian sucks as a technical language. The only reason I could imagine is that computer science today is full of English words, so trying to translate every word to Russian will result in an incomprehensible text, but Russian is happy to adapt words from other languages.
greenish_shores 1 days ago [-]
Yeah sure. And then you have smartphone parts labelled as "дисплей + тачскрин" (to non-speakers: it's "display + touchscreen" written phonetically), lol. Not to say it's bad, though. But it's funny.
Breza 1 days ago [-]
I wonder if it's because English adapts words from other languages when there's a need for a new or more concise phrase.
beambot 2 days ago [-]
It probably helps that you have to be exceedingly thoughful about every keystroke & word less you need to completely retype the document or page!
mhh__ 2 days ago [-]
I'd have imagined you wrote a draft, corrected with the red pen, and then sent it off to (presumably) an army of women to do it properly.
scoot 2 days ago [-]
"lest" perhaps?
At least you don't have to retype the whole sentence. ;)
datadrivenangel 2 days ago [-]
"At one point, I received a well-deserved earful from our machinist about how tightly spaced the turbine blades were. The program was taking nearly a month to run and required tiny end mills that broke often. We performed a turbine blade count study to see if we could use fewer blades with more space between them. It turned out the performance impact of running fewer blades was minimal, so we cut the number down, allowing our machinist to use larger, less fragile tools. Machine time dropped to less than a day, which was a significant win for turbine cost and machine time. It was also a good lesson in thinking comprehensively about a design’s manufacturability (those passages between the blades looked so big on the computer screen!) in addition to its performance. "
Once again people learn the hard way that it's valuable to have tight feedback cycles and embedded knowledge on your team.
FredPret 2 days ago [-]
And also the value of a completely obsessed engineer. If the mech eng designing the parts is also the type to build things in his spare time, this type of machining problem would stand out right away.
Of course, not everything can ever be anticipated, so tight feedback loops are fantastic when you can get them.
numpad0 2 days ago [-]
I'd agree with this take more. It's just cheaper and faster to just know whys and plan ahead than waiting for failures, if you could.
I've been tinkering with 3D printers long enough that I've trivially halved print times after seeing long print time predictions. Lots of my brackets and parts fits together on first try and needs no supports. Rapid turnaround did help in _acquiring_ those skills, but now I could just waterfall little projects and tight looping is not that important.
psunavy03 2 days ago [-]
Valuing "completely obsessed" employees is a great way to build a company with toxic burnout culture. Some people want lives outside of work and are still good at their jobs.
quartesixte 2 days ago [-]
Or some people are so good at their jobs that even while being completely obsessed, they still have great work-life balance.
I interact with a lot of people like the author in the article from this industry. And while yes, their worklife balance skews "work", they all have interesting hobbies and find time to hang out with friends, go on adventures, and live a pretty full life.
Unless you're on the Starship team at SpaceX. Truly, hats off to y'all at Boca Chica some intense hours you are pulling there.
nothercastle 2 days ago [-]
Employees who are married to their job are the best employees. Just like in a real relationship you can treat them like shit and they mostly stay married
greenish_shores 1 days ago [-]
Honestly I did read that as "Employers who are married to their job are the best employers". You probably won't treat them like shit, but they'll still remain married anyway.
But such employees will sometimes leave and build their own stuff. Which they'll very likely succeed at, exactly because of the approach they have.
Ultimately, I think these are a bit different fields/markets, and a bit different kind of jobs. Engineers creating real unique new stuff, vs more "bland" engineers just being a hand to accelerate someone's efforts. I worked in both roles and can clearly see pros and cons of both. Largely depends also on life phase one's at, which one would a person prefer.
quartesixte 1 days ago [-]
It's a lot harder to just spin-off and "build your own stuff" in hardware though, which is I think what keeps the "married employees" around longer. The startup costs are much higher and riskier. And you need a lot more people. Building that rocket engine from scratch probably required around 50 - 60 people to really get it all together.
Also, a rocket engine is a core feature of a rocket (literally cannot fly without it). If they started development of this engine in 2018, that's *six years* of work to get to their current state. Imagine spending 6 years on a core feature of an app that you'd consider "min-viable", and everytime you had a bug the computer you compiled the code on spontaneously combusted?
HeyLaughingBoy 1 days ago [-]
This was one of the main reasons why I didn't have side projects for a very long time. My day job was fun, and it scratched every itch I had. It was such an expensive project that I knew that I simply couldn't afford to do anything that would excite me that much, so I threw all my creative energy into the job.
Eventually though, it became just a job, as it always does. And then the gaze turned elsewhere, looking for more enjoyment and satisfaction.
avmich 1 days ago [-]
> But such employees will sometimes leave and build their own stuff. Which they'll very likely succeed at, exactly because of the approach they have.
Microsoft was known at some time to provide good environment for their engineers so they could focus on making the product, instead of learning the business side of things, which both removed distractions and reduced the incentives to leave and do things without well-learned habits.
guynamedloren 2 days ago [-]
This may surprise you, but it's possible to be completely obsessed with your work (while you're working!), while also maintaining a work-life balance.
psunavy03 2 days ago [-]
It's also a great excuse for abusing people.
mdorazio 2 days ago [-]
Great post on building extremely complex hardware from scratch.
At the same time I hate to be that business guy, but both this blog post and the abl site are missing a good answer to my first question: Why? Given that SpaceX exists and is quickly approaching feasibility of Starship on top of Falcon, what is the primary goal of this rocket system? How will it compete? Who will its customers be? Is it getting its metric ton payload to orbit faster/cheaper/easier? Is this "from scratch" engine design superior to existing designs in some way? What is its current ISP? Is Jet-A + LOX a better fuel choice given expected mission parameters?
I'd love to see a blog post that tackles these kinds of questions.
choeger 2 days ago [-]
From the outside: Diversification is always great. Build a whole ecosystem of small-scale rocket manufacturers instead of one big monopoly. That will foster competition and innovation.
From the investor: SpaceX might fail. Even if there Falcons are pretty much unbeatable now, you don't know what's going to happen with Starship. And even the Falcons could conceivably be grounded for years after some hypothetical flaw is found. More likely: With the price reductions made by SpaceX, the market will grow and there will be more than enough clients.
From the inside: Because it's a fun challenge and literally rocket science, of course.
hinkley 1 days ago [-]
SpaceX was looking to reduce prices to orbit by 10x, and they are currently sitting at around 6.7x.
avmich 1 days ago [-]
I interpret this as that SpaceX has a high margin between market prices and their internal costs, so they can safely reduce prices when needed while remaining profitable. The competitor of course should aim not to the current prices, but to SpaceX's costs to be able to compete on the market.
hinkley 1 days ago [-]
I probably over summarized. I think there’s still room to undercut or compete (particularly on specialty projects) until SpaceX hits 10x for sure, and maybe as high as 15x.
HeyLaughingBoy 1 days ago [-]
And even if there isn't, when SpaceX is booked out for years and you need a launch slot in 6 months, that's when having competition is valuable.
Always look for other ways to compete besides price. (not intended to be as preachy as it sounds :-)
consumer451 1 days ago [-]
Just curious, how did you calculate the 6.7x?
hinkley 39 minutes ago [-]
I found an article that declared pre-and post-SpaceX cost to orbit per kilogram and it was something like 18.5k versus 2.6k (numbers from memory).
Elon before the first Dragon worked was talking about reducing launch costs by a factor of ten.
avmich 2 days ago [-]
SpaceX is certainly giving a hard time to its competitors, but it doesn't mean they shouldn't exist. Some of them may actually follow the same route, designing reusable hardware and reducing launch costs. SpaceX took 20 years to become relying on robustly reusable system; maybe some other companies reach a similar state sooner.
Shawnj2 1 days ago [-]
IIRC ABL’s specific goal is that you can pack an entire launch setup into a shipping container and set one up anywhere in the world. Also the U.S. government will explicitly buy non SpaceX launch contracts specifically to keep smaller launch companies alive so they don’t get locked into a single supplier.
AndriyKunitsyn 2 days ago [-]
Nice read. The fact that it is possible to 3d print metal parts that withstand temperatures and pressures of a rocket engine is so exciting. How expensive is it?
generuso 2 days ago [-]
The material costs (the $300 per kg of titanium suggested in another comment) are only a small part of the overall expense. Electron beam sintering printer time typically costs $100-$200 per hour, and a large build can easily take multiple days.
After the printing itself, one will have to remove to loose powder, which for small cooling channels in the walls of the combustion chamber is very challenging and time consuming.
After that, some post-processing may also be necessary. One process for achieving the greatest strength is hot isostatic pressing, when the part is baked in a furnace in a retort filled with a very high pressure inert gas.
Specifically for rocket engines, it is also desirable to have a layer with the high heat conductivity on the inside, typically made of a copper-based alloy, and the external structure from a higher strength material. This means either bi-metallic printing, which is a rather niche process, or some metal deposition process over the printed part.
In addition to this, there is usually quality control, for example, high resolution industrial computed tomography, to make sure that the invisible internal features have been fabricated and cleaned out correctly.
In addition to the additive steps, it will also be necessary to machine the features which are impractical or impossible to build sufficiently accurately.
Mostly depends on the volume of the part, or equivalently it's weight. Complexity you get mostly "for free" when it comes to 3d printing. What type of material you need to "withstand temperatures and pressures of a rocket engine" is entirely dependent on which part of the rocket engine we're talking about. A fuel injector has radically different requirements than a supporting strut for example.
3d printed titanium goes for 300-400 USD/kg, steel is a bit cheaper at ~150 USD/kg for most inconel grades.
avmich 2 days ago [-]
Paul Breed, from Unreasonable Rocket team - https://x.com/unrocket - mentioned, a decade or so ago, that he printed some aluminum engines for regenerative cooling by hydrogen peroxide for ~$1000 . Another story from http://rocketmoonlighting.blogspot.com/2010/ is about a small engine cooled with nitrous oxide - and manufactured entirely on personal money, also quite some time ago. I think these numbers are still indicative of the current prices.
quartesixte 2 days ago [-]
Aluminum is magnitudes cheaper than Inconel. And since volume is cubic, and pricing mostly on based on powder weight, you are about an order of magnitude or two off for the size of engine ABL is producing here.
avmich 2 days ago [-]
That's correct, but it's still interesting that you have that opportunity to shave - slash? - costs here.
And also the other engine mentioned isn't an aluminum one.
aaronblohowiak 2 days ago [-]
Would $100,000 still be a “steal” for all that? (Especially with repeatability and nimbleness) ?
quartesixte 2 days ago [-]
Very. Very. Expensive.
Inconel powder is also Not That Great for your health and at the particle-size the printers rocket companies use, you need full PPE to safely handle the loose powder floating about.
The machines themselves are also expensive. Think in the millions of USD. EOS, SLM, and Velo3D are key players in this market. They require a fair bit of space, and training to use correctly.
You probably need a mechanical engineer who is well-versed in materials science and has a tolerance for finicky machines that constantly breakdown.
Then you have the metal powders. Which, also potential million or two.
And then you have all the associated infrastructure needed. High voltage power. Gas (Nitrogen, Helium, Argon, etc etc) in the thousands of liters per month. Waste disposal. Safety (some alloys are flammable in their powder form). Climate control (the powders are sensitive to the environment. Humidity will quickly destroy your powder supply). Tooling (the base-plates metal printers used are machined from solid blocks of steel).
And last but not least, any of the post-printing work. Heat treat. Coatings. Analysis. CNC Machining.
3D Printing metal on industrial scales is a CAPEX intensive endeavor, and not for the faint of heart.
jfoutz 2 days ago [-]
Stratasys? I’m not sure about pricing, and the website won’t say.
However, a bunch of places rent out time on those machines. Draw up your rocket, and get a quote. Price is generally cc^2 volume
Metal is not cheap. Make a few out of plastic to verify dimensions.
quartesixte 2 days ago [-]
Plastic to verify dimensions is a great approach.
But don't forget that the laser sintering of metal powders might result in design constraints not present in plastic printing!
spxneo 2 days ago [-]
side question to this: where can i design stuff involving metal parts (presumably in CAD tools) and have it printed en masse? With PCBs? ex) car components
numpad0 2 days ago [-]
You can draw up mechanical components in Autodesk Fusion, OnShape, SOLIDWORKS for Makers, or FreeCAD, and send STEP or STL to PCBWay or JLCPCB in China for manufacturing(note that export restrictions may apply if it's literal rockets or otherwise dual-use/controlled in nature).
PCB mounting outlines can be exported from above 3D CAD and imported to EDA tools such as Altium and KiCAD; KiCAD is fine unless you're doing DRAM or PCIe. Same PCBWay and JLCPCB takes your design, and optionally assemble PCB with parts for you.
That should take you to first 2-3 working units at ~$500 and up to few dozen beta units with zero initial cost and much inflated unit costs, and I guess beyond that involves significant human resourcing and networking problems outside of PoC hardware scope.
spxneo 2 days ago [-]
thank you so much for this detailed answer. now i just need to invest some time into learning CAD and KiCAD
Robelius 2 days ago [-]
You could try a battery powered phone charger since it's a "relatively simple" first project. The big hurdle for learning these types of tools is usually "What buttons do I press to create the output that I want.
For the electrical side, there are plenty of schematics online that you can try to copy or use as a starting point. And the CAD side can be a simple box with snap fits. I'd recommend OnShape if you're just starting out since it's the lowest barrier of entry, but Fusion 360 is also good. All in, it should be <$150 for the PCBs + Components + 3D Prints.
After you get the satisfaction of seeing your device charge from something you made, then you'll start getting the itch and find more excuses to make things.
spxneo 2 days ago [-]
I'll follow your recommendation and try the simple stuff. Looks like OnShape is right up my alley. All very exciting feels like I'm "programming hardware" !
quartesixte 2 days ago [-]
And once you are done, services like Xometry allow you to print out the metal by having them source a printing vendor from their network.
HeyLaughingBoy 1 days ago [-]
3D printing is very popular right now. And for good reason. However, it often masks the fact that there are many ways to manufacture most products, and often, 3D printing is the most expensive one.
Meaning that instead of thinking "how do I 3D print this?" you should be thinking "how do I manufacture this?"
Something as simple as making a drawing, specifying the material and quantity needed and then going on reddit/r/manufacturing and asking "how would I build 50 of these" can provide very useful answers, even if you have to do a bit of research later to understand what you've been told.
criddell 1 days ago [-]
> You might call me an unlikely candidate to lead an engine program from scratch, but I was hired by ABL in 2018 to do just that. My background was in commercial aircraft interiors, web development, semiconductor fab fluid components, and SpaceX Falcon 9 hydraulic systems.
I don't mean this as an insult, but why did they hire you? It's obvious now that you were a great choice, but from your background story I wouldn't have guessed that to be true.
quartesixte 1 days ago [-]
Seems like from the blogpost that the writer and the founder were part of the same cohort at SpaceX. I would hazard a guess that they became friends, and had planned to do this together, and he joined ("hired") as soon as feasible for him (or the founder gained enough traction to pull him away from SpaceX).
quartesixte 19 hours ago [-]
Oh and as an additional comment: Propulsion Engineers are a niche, specialized branch of mechanical engineers. They are the ones who usually design engines.
The writer probably was referring to the fact that he was just a regular mechanical engineer and not a Propulsion Engineer.
cuSetanta 2 days ago [-]
Oh wow, I work for a supplier for ABL and am today in the process of putting some of their stuff into our thermal chamber for cycling. Thats neat.
We work for a lot of launcher companies, but ABL is the most interesting for me (even though we do relatively little for them). The containerised approach to the entire system is a really clever adaptation of existing methods to create a rapid launch system.
philipwhiuk 1 days ago [-]
The jury is very much out on 'rapid'.
mrbluecoat 44 minutes ago [-]
> Example of a Clean Sheet
lol, engineering humor
hi-v-rocknroll 1 days ago [-]
Since it's 3D printed, I'm guessing from the embedded ports that the nozzle is hollow in parts and Jet A cooled since LOX latent heat of evaporation is orders of magnitude less. Probably one of those ports is for a temperature sensor.
avmich 2 days ago [-]
Awesome story, thanks!
It seems the design choices are rather conservative, which is entirely justified by the "from scratch" part for the first engine. I'm sure subsequent designs will be more bold and adventurous.
Keep up great work!
z3t4 2 days ago [-]
The science of pressure chambers have also advanced, we could just pump whatever material, like liquid air into a pressure tank and then load it into the rocket. No mixing or pumping needed just open the valve and let the pressure out and you will have a very cheap and simple rocket.
sr-latch 2 days ago [-]
This is absolutely not true - injector design is the most important aspect of designing a thrust chamber. Poor mixing of propellants leads to severe combustion instability, which often leads to explosions. Even the earliest space programs did significant testing on propellant choices and injector designs (see Ignition! by John D. Clark)
Also, pressure fed rockets have always been a fairly terrible design. Pressure feeding requires heavy tanks, and incurs a big mass fraction (dry mass / wet mass) penalty. Outside of rare cases, it's only used for ground testing.
z3t4 2 days ago [-]
just drop the tank when the weight/thrust ratio is too low. Thanks for the book suggestion! (have not read it yet)
quartesixte 1 days ago [-]
The rocket equation would like to have a word with you. The wall thicknesses required to create rockets with enough thrust to get to orbit on pressure-fed would render the rocket physically impossible.
There is also a lot of control that goes into flying a rocket, and pressure-fed rockets are kind of hard to control.
alfor 1 days ago [-]
I was wondering what is that space company and what are their edge with spaceX.
On the site you can see: launch on demand, simple system that can go anywere, tactical launchs.
This is for nukes or similar stuff.
philipwhiuk 1 days ago [-]
It's not for nukes. We have silos and submarines for those. It's for "responsive launch" and (skeptically) because the DoD has lots of money for space and not much idea what to do with it.
It's the Astra business model, hopefully without the Astra failure model.
(And practically speaking it's because you can't bootstrap a heavy lift launch company on VC funding or even a SPAC - the small sat launcher is a proof-of-concept for your medium/large launch vehicle).
spxneo 2 days ago [-]
now all that is required is a github for passive radar...for educational purposes
Is this the codebase that they took down ???! Yes to all of the things you can do (minus the passive radar stuff beyond educational purposes that is ;)
I have an incomplete set of the radlab textbooks. They're still useful even today, and have a really careful pace to them because they were written for a generation for whom electricity was still relatively new.
One of the things that is a real shame is just how artfully bound those old books are. Leather, thick but smooth paper, etc.
- Yellow is bad
- The 60s were awesome
Out of context of the thread, your second point was amusingly interpreted to be about LSD.
Recently I had to write in Russian (my native language) a tech doc of many pages. That is after 26 years of tech writing only in English (my 2nd language). That experience resulted in an epiphany for me on why Russia is so technically behind as I suddenly understood what Zadornov was talking about :) In comparison to English, Russian sucks, to say the least, as a technical language. All the things which make Russian great for literature and poetry make it terribly inefficient for tech writing, miles and miles behind English. If anything, I think English is the secret sauce of the success of the Western technical civilization.
(For older Russian speakers - if you remember another Zadornov's "dolbani pljuhalkoj po kuvykalke, prikin'sja vetosh'ju i ne otsvechivaj" - now I think it really comes from the same weakness of Russian for technical communication)
Check it out, the things for which a western scientist or engineer is given credit, were discovered/invented much earlier by soviet counterparts! What do you think about Kotelnikov?
But it is a common and easy trap for a lot of nationalities to fall into, because there are innumerable discoveries that happen before (and/or independent of) the canonical "inventor" (and you're automatically more likely to know the independent inventors if they come from your country!).
Regarding Kotelnikov specifically: You could make the same argument (re: discovery of sampling theorem) for Whittaker, who published in 1915; ultimately, though, the whole debate is mostly pointless.
I strongly believe that no single inventor so far was truly "significant", in that his nonexistence would have delayed science as a whole by more than a decade or two (consider Newton/Leibniz for calculus, Einstein/Poincaré/Hilbert for relativity, etc.).
People should not focus so much on WHO discovered a particular fact, because the cold truth is that it's mostly a personality cult and that any single scientist that ever existed, no matter how brilliant, was still replaceable (from a "human progress" kind of view). Which does not stop me from being a Fermi-fanboy.
But I completely agree with you that language did not really hinder USSR science.
I found the MBA.
If Sergei Korolev didn’t die suddenly and unexpectedly, the Soviets may have actually won the race to the moon. Their space program atrophied afterwards and struggled to succeed.
I really wonder at the modern obsession with associating people with cattle.
Computer servers can be divided into two roles in modern technical architectures… they are either “cattle” or “pets”. Pets are computer servers that have names and are always up. Cattle are servers that are transient, spun up and down as needed and do not necessarily have any long running identity/name as a component of a larger system.
http://cloudscaling.com/blog/cloud-computing/the-history-of-...
The poster is making a critiques of how by treating historical persons contributors as cattle, we are considering them a dispensable, unnamed, a commodity that is easily replaced and interchangeable and missing their very real contribution, value, and humanity.
I do find the Great Person theory and its critiques fascinating. I think of how Kennedy navigated the Cuban Missile Crisis and avoided nuclear war, then I think of how the sheer consensus of the US military after WW2 was to build a huge nuclear arsenal and use it any possible chance.
Nope, thats a false positive.
Also cutting the quote there heavily twists the meaning: I'm not saying those scientists were replaceable as persons, just that their effect on all of humanities scientific progress was.
Many persons have a strong notion that we owe certain discoveries to a specific person, but this does not even hold up to cursory examination in my view (those discoveries would have been made in short order by someone else).
I'm very curious though if you have counterexamples, or think the premise is otherwise flawed.
I suspect we can find counterexamples if look enough, though to truly present some a serious knowledge of science history is needed.
What do you think of contributions of Srinivasa Ramanujan and George Cantor?
For Cantor, I think the maximum delay in results would've been even less, but maybe the impact (=> set theory) bigger during that time?
I will concede that there is a lot of value that any specific scientist provides just from correspondence/communication alone which is very hard to quantify.
I also think if you took away whole institutions from a hypothetical timeline, like, e.g. the University of Göttingen, then the impact could be quite clear (more than just a decade of lost progress in some field). So maybe you could argue that some founders of prodigious institutions helped human science more than any single scientist? But this is highly hypothetical (if the people AT those institutions would have existed regardless). Also a distasteful thought (to me).
At least you don't have to retype the whole sentence. ;)
Once again people learn the hard way that it's valuable to have tight feedback cycles and embedded knowledge on your team.
Of course, not everything can ever be anticipated, so tight feedback loops are fantastic when you can get them.
I've been tinkering with 3D printers long enough that I've trivially halved print times after seeing long print time predictions. Lots of my brackets and parts fits together on first try and needs no supports. Rapid turnaround did help in _acquiring_ those skills, but now I could just waterfall little projects and tight looping is not that important.
I interact with a lot of people like the author in the article from this industry. And while yes, their worklife balance skews "work", they all have interesting hobbies and find time to hang out with friends, go on adventures, and live a pretty full life.
Unless you're on the Starship team at SpaceX. Truly, hats off to y'all at Boca Chica some intense hours you are pulling there.
But such employees will sometimes leave and build their own stuff. Which they'll very likely succeed at, exactly because of the approach they have.
Ultimately, I think these are a bit different fields/markets, and a bit different kind of jobs. Engineers creating real unique new stuff, vs more "bland" engineers just being a hand to accelerate someone's efforts. I worked in both roles and can clearly see pros and cons of both. Largely depends also on life phase one's at, which one would a person prefer.
Also, a rocket engine is a core feature of a rocket (literally cannot fly without it). If they started development of this engine in 2018, that's *six years* of work to get to their current state. Imagine spending 6 years on a core feature of an app that you'd consider "min-viable", and everytime you had a bug the computer you compiled the code on spontaneously combusted?
Eventually though, it became just a job, as it always does. And then the gaze turned elsewhere, looking for more enjoyment and satisfaction.
Microsoft was known at some time to provide good environment for their engineers so they could focus on making the product, instead of learning the business side of things, which both removed distractions and reduced the incentives to leave and do things without well-learned habits.
At the same time I hate to be that business guy, but both this blog post and the abl site are missing a good answer to my first question: Why? Given that SpaceX exists and is quickly approaching feasibility of Starship on top of Falcon, what is the primary goal of this rocket system? How will it compete? Who will its customers be? Is it getting its metric ton payload to orbit faster/cheaper/easier? Is this "from scratch" engine design superior to existing designs in some way? What is its current ISP? Is Jet-A + LOX a better fuel choice given expected mission parameters?
I'd love to see a blog post that tackles these kinds of questions.
From the investor: SpaceX might fail. Even if there Falcons are pretty much unbeatable now, you don't know what's going to happen with Starship. And even the Falcons could conceivably be grounded for years after some hypothetical flaw is found. More likely: With the price reductions made by SpaceX, the market will grow and there will be more than enough clients.
From the inside: Because it's a fun challenge and literally rocket science, of course.
Always look for other ways to compete besides price. (not intended to be as preachy as it sounds :-)
Elon before the first Dragon worked was talking about reducing launch costs by a factor of ten.
After the printing itself, one will have to remove to loose powder, which for small cooling channels in the walls of the combustion chamber is very challenging and time consuming.
After that, some post-processing may also be necessary. One process for achieving the greatest strength is hot isostatic pressing, when the part is baked in a furnace in a retort filled with a very high pressure inert gas.
Specifically for rocket engines, it is also desirable to have a layer with the high heat conductivity on the inside, typically made of a copper-based alloy, and the external structure from a higher strength material. This means either bi-metallic printing, which is a rather niche process, or some metal deposition process over the printed part.
In addition to this, there is usually quality control, for example, high resolution industrial computed tomography, to make sure that the invisible internal features have been fabricated and cleaned out correctly.
In addition to the additive steps, it will also be necessary to machine the features which are impractical or impossible to build sufficiently accurately.
Together, these steps add to a significant cost.
Some of the above processes can be seen in this video: https://www.youtube.com/watch?v=7pXEf0wHU1Y
3d printed titanium goes for 300-400 USD/kg, steel is a bit cheaper at ~150 USD/kg for most inconel grades.
And also the other engine mentioned isn't an aluminum one.
Inconel powder is also Not That Great for your health and at the particle-size the printers rocket companies use, you need full PPE to safely handle the loose powder floating about.
The machines themselves are also expensive. Think in the millions of USD. EOS, SLM, and Velo3D are key players in this market. They require a fair bit of space, and training to use correctly.
You probably need a mechanical engineer who is well-versed in materials science and has a tolerance for finicky machines that constantly breakdown.
Then you have the metal powders. Which, also potential million or two.
And then you have all the associated infrastructure needed. High voltage power. Gas (Nitrogen, Helium, Argon, etc etc) in the thousands of liters per month. Waste disposal. Safety (some alloys are flammable in their powder form). Climate control (the powders are sensitive to the environment. Humidity will quickly destroy your powder supply). Tooling (the base-plates metal printers used are machined from solid blocks of steel).
And last but not least, any of the post-printing work. Heat treat. Coatings. Analysis. CNC Machining.
3D Printing metal on industrial scales is a CAPEX intensive endeavor, and not for the faint of heart.
However, a bunch of places rent out time on those machines. Draw up your rocket, and get a quote. Price is generally cc^2 volume
Metal is not cheap. Make a few out of plastic to verify dimensions.
But don't forget that the laser sintering of metal powders might result in design constraints not present in plastic printing!
PCB mounting outlines can be exported from above 3D CAD and imported to EDA tools such as Altium and KiCAD; KiCAD is fine unless you're doing DRAM or PCIe. Same PCBWay and JLCPCB takes your design, and optionally assemble PCB with parts for you.
That should take you to first 2-3 working units at ~$500 and up to few dozen beta units with zero initial cost and much inflated unit costs, and I guess beyond that involves significant human resourcing and networking problems outside of PoC hardware scope.
For the electrical side, there are plenty of schematics online that you can try to copy or use as a starting point. And the CAD side can be a simple box with snap fits. I'd recommend OnShape if you're just starting out since it's the lowest barrier of entry, but Fusion 360 is also good. All in, it should be <$150 for the PCBs + Components + 3D Prints.
After you get the satisfaction of seeing your device charge from something you made, then you'll start getting the itch and find more excuses to make things.
Meaning that instead of thinking "how do I 3D print this?" you should be thinking "how do I manufacture this?"
Something as simple as making a drawing, specifying the material and quantity needed and then going on reddit/r/manufacturing and asking "how would I build 50 of these" can provide very useful answers, even if you have to do a bit of research later to understand what you've been told.
I don't mean this as an insult, but why did they hire you? It's obvious now that you were a great choice, but from your background story I wouldn't have guessed that to be true.
The writer probably was referring to the fact that he was just a regular mechanical engineer and not a Propulsion Engineer.
We work for a lot of launcher companies, but ABL is the most interesting for me (even though we do relatively little for them). The containerised approach to the entire system is a really clever adaptation of existing methods to create a rapid launch system.
lol, engineering humor
It seems the design choices are rather conservative, which is entirely justified by the "from scratch" part for the first engine. I'm sure subsequent designs will be more bold and adventurous.
Keep up great work!
Also, pressure fed rockets have always been a fairly terrible design. Pressure feeding requires heavy tanks, and incurs a big mass fraction (dry mass / wet mass) penalty. Outside of rare cases, it's only used for ground testing.
There is also a lot of control that goes into flying a rocket, and pressure-fed rockets are kind of hard to control.
On the site you can see: launch on demand, simple system that can go anywere, tactical launchs.
This is for nukes or similar stuff.
It's the Astra business model, hopefully without the Astra failure model.
(And practically speaking it's because you can't bootstrap a heavy lift launch company on VC funding or even a SPAC - the small sat launcher is a proof-of-concept for your medium/large launch vehicle).
The SDR world is incredible
edit: looks like they took down all the passive radar doppler videos : https://othernet.is/products/kerberossdr-4x-coherent-rtlsdr