Thanks Vince Ferrer, Moonman62, and SunTzuWu.Both companies (Blue Origin and SpaceX) are working on methane-burning engines; the cryo H O engine used on this suborbital craft won't get to orbit even scaled up. That problem was addressed during the Apollo years by using cryo upper stages but the big booster that got those systems into space used RP-1 (a purified kerosene) oxidized with liquid oxygen -- the same combo he'd used in the V2.
The Soviets had copied the V2 engine (there's a nice surviving photo of Sergei Korolev in uniform, standing next to a captured V2 engine in 1945) and scaled it up, and refined it over the past 70 years, such that the *completely unsubsidized* defense contractors use Russian multi-generation derivations of the V2 engine to launch payloads of various kinds, both military and commercial.
Musk wants a methane-burner because of the extra pop, but also because methane is said to be available on the surface of Mars, whereas the Martians are fresh out of RP-1. Bezos wants a methane-burner in order to ferry a bunch of *completely unsubsidized* but no doubt appropriately remunerated rich celebrities into Earth orbit, and eventually to lunar orbit, and safely back to Earth.
I very much doubt space travel will ever be quite as safe as airline travel, btw.
Enough already -- let's get back to fighting about Trump or Cruz. ;')
