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Graphene at 20: still no sign of the promised space elevator, but here’s how this wonder material is quietly changing the world (theconversation.com)

submitted 3 months ago by [email protected] to c/[email protected]

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[–] [email protected] -1 points 3 months ago (1 children)

Even reusable rockets use a tremendous amount of fuel. Falcon 9 burns 700,000 gallons per second.

[–] [email protected] 7 points 3 months ago (2 children)

Untrue, that's many times over the 25,000 gallons of kerosene they keep on board. That's still a lot of gas, but not 700,000 gallons, not by a long shot. If it burned that much per second it wouldn't even produce enough thrust to carry its own fuel payload

[–] [email protected] 4 points 3 months ago

My bad for trusting Google top result.

395,700 kg fuel first stage. Burn time 162 seconds.

https://en.m.wikipedia.org/wiki/Falcon_9#:~:text=The%20rocket%20has%20two%20stages,rocket%2C%20carrying%20143%20into%20orbit.

25,000 gallons of kerosene they keep on board.

The 39,000 gallons of LOX in the Falcon 9 doesn't make itself.

[–] [email protected] 3 points 3 months ago* (last edited 3 months ago)

To inject a source, there's 395,700 kg total propellant on the first stage, and a burn time of 162 seconds. That gives about 2,442.6 kg/second, and assuming it's fuel balanced it comes out to something like 700 liters of RP-1 per second. Could OP have been using thousands of gallons instead, by accident?

It's still a lot, though, while a space elevator is just a really tall elevator, or alternatively an EV that goes up and down.