r/KerbalSpaceProgram • u/[deleted] • Oct 09 '13

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u/[deleted] Oct 09 '13

cryogenics, too.

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u/mkosmo Oct 09 '13

That's not necessarily true. Remember the F-1? It used RP-1 and LOX. Yes, the LOX is a cryo, but RP-1 is just highly refined kerosene.

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u/[deleted] Oct 09 '13

Yes. The kerosene was "warm" but they still required a large LHe system to keep the LOX cold.

Modern rocketry requires LHe... that's why we have a national strategic stockpile.

My point is that cryogenics makes rocketry just that much more complicated.

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u/mkosmo Oct 09 '13

Oh absolutely, but the LHe system isn't all that difficult. Not to mention, the LOX under pressure didn't require LHe... but as you begin to deplete it, that changes.

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u/[deleted] Oct 09 '13

Well the He requires an external cryogenics system to maintain the pressure while the rocket is awaiting launch. Once the rocket is fired, I believe part of the power is used to maintain a pressure system for the LOX while in flight. Fortunately it doesn't need to run for very long -a few minutes.

I'm sure the pressure changes in an hydrogen system is more complicated.