> “Well they survived long enough to achieve space flight,” Forty-five Trills pointed out. “They can’t be too careless with explosions, can they?” ...
... said no-one familiar with the history of human rocketry.
On which subject, did you know that Ignition! is back in print? Now that book definitely shouldn't be taken as a challenge.
The relevant passage from John Clark's "Ignition!":
>”It is, of course, extremely toxic, but that’s the least of the problem. It is hypergolic with every known fuel, and so rapidly hypergolic that no ignition delay has ever been measured. It is also hypergolic with such things as cloth, wood, and test engineers, not to mention asbestos, sand, and water-with which it reacts explosively. It can be kept in some of the ordinary structural metals-steel, copper, aluminium, etc.-because of the formation of a thin film of insoluble metal fluoride which protects the bulk of the metal, just as the invisible coat of oxide on aluminium keeps it from burning up in the atmosphere. If, however, this coat is melted or scrubbed off, and has no chance to reform, the operator is confronted with the problem of coping with a metal-fluorine fire. For dealing with this situation, I have always recommended a good pair of running shoes.”
The Apollo rockets used kerosene and liquid oxygen for their first (and largest) stage. The later stages used hydrogen and oxygen, instead.
Collecting and compressing large amounts of hydrogen is unbelievably dangerous, and liquid oxygen isn't far behind - but neither is exactly rare. Kerosene is an article of commerce, and while you'd want to control purity fairly carefully for rocket fuel, which costs, it's more that you need a staggering amount of it than that the fuel itself is unusually expensive.
Interestingly, one of the best books ever written on this subject, Ignition!, is back in print. I highly recommend it if you have any interest in rocketry whatsoever: it covers fuel development, spanning most of the period from the late 19th century all the way up to the Cold War. Clark's style is also eminently quotable:
> [Chlorine trifluoride] is, of course, extremely toxic, but that’s the least of the problem. It is hypergolic with every known fuel, and so rapidly hypergolic that no ignition delay has ever been measured. It is also hypergolic with such things as cloth, wood, and test engineers, not to mention asbestos, sand, and water-with which it reacts explosively. It can be kept in some of the ordinary structural metals-steel, copper, aluminium, etc.-because of the formation of a thin film of insoluble metal fluoride which protects the bulk of the metal, just as the invisible coat of oxide on aluminium keeps it from burning up in the atmosphere. If, however, this coat is melted or scrubbed off, and has no chance to reform, the operator is confronted with the problem of coping with a metal-fluorine fire. For dealing with this situation, I have always recommended a good pair of running shoes.
According to the phenomenal book "Ignition!", that's pretty much how modern rocket propellant came about. They did some theoretical work, but most of it was just "This might make a good combination, or it might blow up. Let's try it!"
It's an engineering euphemism. RUD (Rapid Unscheduled Disassembly) is a common abbreviation used in engineering circles. I believe the origination of the phrase was first mentioned in the 1970s book Ignition! which was a book a lot of future rocket and aerospace engineers would read before going in to the field.
"Returned to Kit Form" is a common way to say "it exploded" in model rocketry circles as well. It's just something engineers say because it sounds more intelligent than "blew up" or "exploded"
TL;DR: Sure, you can do that. But the more energy you pack in, the more it starts looking like an explosive, with all the problems that entails.
Look up monopropellants. For a light hearted treatement of monoprops in John D. Clark's <strong>Ignition</strong>
It was reprinted recently. https://www.amazon.com/Ignition-Informal-Propellants-University-Classics/dp/0813595835/ref=sr_1_1?dchild=1&keywords=Ignition&qid=1635011105&s=books&sr=1-1
(not a big fan of Amazon, but showing that it is not hard to find)
I've made a fair amount of diborane. It's awful stuff. First you have to pump down your Stock vacuum line to 10^-4 atm (I think) using a mechanical pump and a mercury diffusion pump. Then you have keep checking there or no small leaks. And there was always slow leaks. And diborane smells horrible.
I made B2H6 from lithium aluminum hydride and boron trifluoride (dissolved in ether). It took about a day to make and purify ~0.25 mol, and by the end of the day, I was pretty wasted.
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From the diborane, I made tetraborane, and then a ethylene adduct of tetraborane.
After one spectacular detonation, I discovered what I believe is the most stupid way to make polyethylene.
Fires, bangs and broken glass - not fun
btw the 3 centered bond was called a "banana" bond.
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There is a wonderful book on the development of liquid rocket fuels. Years ago a copy was precious, but now you can get Ignition! on Amazon
There is a chapter on "The Billion Buck Boron Booboo".
Actually, the history of rockets is ridiculously amazing. I recommend this book as a journey through it:
https://www.amazon.com/Ignition-Informal-Propellants-University-Classics/dp/0813595835
Also, you have to plan these conversations out in your head and it takes a while before you build up enough steam to get it out. Sometimes the timing is off.
I empathize with husband.
It's not just about lh2 being cryogenic. Plenty of other fuels are cryogenic as well, as is liquid oxygen, just about the most popular oxidizer.
It's that lh2 has a terribly low density. 0.08376 kg/m3, compared to another low density fuel, methane at 0.65119 kg/m3. The isp is very good, but the amount of tank your need to carry around to get that isp is insane. That's why we see many vehicles opt for kerosene or more recently methane as fuels. They're much more dense, so the vehicle can be much smaller.
If you're interested in these things, check out Ignition!. It's a fantastic nonfiction mix of crazy mad scientist commentary and interesting info with regard to rocket fuels and oxidizers. It was out of print and freely available on the internet for a while, but with the most recent print run they may be enforcing copyright again. It's worth paying for, in my opinion.
Ignition! by John D. Clark is a great resource as well. It details the history of propellant chemistry, and it should be useful to you in choosing a fuel type.
It's not so much about liquid fuel engines, but if you're planning on building the motor you'll need to understand propellant chemistry. https://www.amazon.com/dp/0813595835/ref=cm_sw_r_cp_apa_i_0Su7Db5AZVC9V
Maybe consider trading book ingition. It is about rocket propellants from 1950's.
SpaceX has done nothing innovative in rocketry. Their innovation is purely on the business side. Reusable launch vehicles existed long before SpaceX, all the way back to the 50s. The technology wasn't leveraged back then because launch cost mattered a lot less than performance.
All of the tech being used by SpaceX today was invented in the 50s and 60s and then shelved, including methane engines, reusable SSTOs, and even more 'futuristic' technologies like aerospike engines that still haven't yet been resurrected. Even when it comes to economies of scale, SpaceX is only executing on a pretty tame strategy. For extreme economy at extreme scale, there's the Sea Dragon.
If you want to get a grasp on how advanced rocketry was in the 50/60s and how little we've come since then, I suggest the amazingly written Ignition! by John D Clark, one of the pioneers of the field.
https://library.sciencemadness.org/library/books/ignition.pdf (free pdf)
https://www.amazon.com.au/Ignition-John-Clark/dp/0813595835 (recent reprint)
Get him this book: Ignition!
It is an intimate history of liquid-fueled rocket engines. It is fantastic. Unless, of course, he already has it.
Ignition!: An Informal History of Liquid Rocket Propellants (book)
I believe this is some edition of the book available for free online: ignition.pdf
I’m not sure ammonia is applicable to jet engines - I’m sure it’s been tried. Ammonia has been used as the fuel and oxidiser for rockets but by itself has too little impulse. It may show promise as a rechargeable battery substitute.
If you haven’t read it, look up Ignition! by Iohn Drury Clark for all you might ever want to know about setting fire to dangerous chemicals in the name of “coz I can”.
If you want to know more I loved reading Ignition!: An Informal History of Liquid Rocket Propellants
Turns out there’s a new reprint available and even an audio book 😀
On a side note, Ignition!: An Informal History of Liquid Rocket Propellants is awesome.
From a recommendation in a Derek Lowe Things I Won't Work With post (read the whole section, there are many more explodey entries), it seems there are whole specialities that started off like that.
Get this:
https://www.amazon.com/Ignition-Informal-Propellants-University-Classics/dp/0813595835
I think there may be a free pdf copy floating around too. At least there was for a while when it was out of print.
It's been reprinted, although it looks like Amazon may not have it in stock currently.
They recently did a reprint! You can get it for $20 on Amazon now.