I discovered recently that helium is not combustible......I mistook it for hydrogen.
It seems you CAN learn something new ON FR...
occasionally anyway. Lol!
I knew it wasn’t helium in the Hindenburg...just couldn’t remember which gas was used. Thanks for the reminder! I hate getting old...
HElium is very expensive / in short supply, and lacks mass, which you need for a thruster. I’m surprised they don’t use something like Argon or even Krypton, that has more mass and is similarly non-combustible.
> I discovered recently that helium is not combustible..
But you can compress it and heat it up a couple hundred million degrees and fuse the atoms together ;-)
Recently?
You might be interested to know that helium is also the most leak-prone gas of them all. More so even than hydrogen. It's used as a trace gas to detect leaks in vacuum systems.