5 ms·
SpaceX, ULA, Blue Origin, and eventually Ariane are all headed towards methane.
by greglindahl 10y ago
SpaceX, ULA, Blue Origin, and eventually Ariane are all headed towards methane.
- dredmorbius 10y agoThat's a Mars-driven strateegy, no?
- neolefty 10y agoSpaceX 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