Re: LOX/CH4

On Sun, 25 Nov 2007 15:15:38 -0800 (PST), ohara5.0@xxxxxxxxxxxxxx wrote:

Am I correct in thinking that for a given amount of O2 that a fuel
tank for CH4 would be 1/4 the size of the size of a LH2 tank?

Closer to one-half.


Given the storability of CH4 vs LH2, I'd think a LOX/CH4 engine would
be an extreme priority of NASA and am surprised it has not been developed.

Given the performance of CH4 vs LH2, it's an extremely low priority. Or
perhaps that should be phrased, given the storability of CH4 vs RP1, it's
a very low priority.

LOX/Methane has about the same performance as LOX/Kerosene, and Kerosene
is even more storable than Methane. There are arguments to be made that
we might put up with the extra hassle (especially if we're already using
LOX), for the slight improvement in performance, but the idea that Methane
offers Hydrogen-like performance in a storable package, is just plain
wrong.

Methane is a hydrocarbon fuel, not hugely superior to other hydrocarbon
fuels, and we've already got perfectly good hydrocarbon-fuel engines.
Mind you, at this point most of them are *Russian* engines, but the
Russians have got capitalism pretty much down by now.


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