Re:How much bigger could Earth be before rockets wouldn't work?
by jasonwatkinspdx on Saturday February 03, 2024 @08:36PM
(#39246658)
The basic physics of https://en.wikipedia.org/wiki/SABRE_(rocket_engine) have been vetted, which is an air breathing rocket engine. I don't know how much difference trying to liquify H2 vs O2 is though.
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Re:How much bigger could Earth be before rockets wouldn't work?
by jaggederest on Saturday February 03, 2024 @08:45PM
(#39246710)
The oxygen is the majority of the mass (but not volume!) in a stoichiometric hydrogen engine, so the mass savings would be less I think. The RS-25 (space shuttle main engine) runs at a higher fuel ratio. Should work very similar to SABRE in general - the concept of a high speed atmosphere collector and precooler is pretty universal to any gas, and hydrogen has an extremely high heat transmission rate.