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SpaceX claims methane's better for engine reusability (much less soot buildup) but that's as yet unproven. Efficiency is similar to kerosene.
by neolefty 10y ago
SpaceX claims methane's better for engine reusability (much less soot buildup) but that's as yet unproven. Efficiency is similar to kerosene.
- dredmorbius 10y agoShould be only 85% of the net energy by weight if I understand petroleum vs. alcohol correctly. Actually, much worse: 46 MJ/kg for kero, 19.6 MJ/kg for methanol. https://en.m.wikipedia.org/wiki/Energy_density https://en.m.wikipedia.org/wiki/Energy_density
- maxerickson 10y agoMethane, not methanol. Presumably liquefied. 53.6 MJ/kg at your link.
- dredmorbius 10y agoDoh! Too much blood in my caffeine system. Worse by volume, even liquified: 22.2 KJ/l vs. 37.4 KJ/l kero. Though the mass savings should trade that off some as well.
- dredmorbius 10y agoAnd more on the RP11 vs CH4 tradeoffs: https://space.stackexchange.com/questions/3161/why-is-spacex-considering-methane-as-fuel-for-their-next-engine-the-raptor https://space.stackexchange.com/questions/3161/why-is-spacex... 2004 technical paper out of Germany: http://arc.aiaa.org/doi/pdf/10.2514/1.2672 http://arc.aiaa.org/doi/pdf/10.2514/1.2672