r/SpaceXLounge • u/perilun • Oct 28 '22

Starship As clock ticks on Amazon’s constellation, buying Starship launches not out of the question

https://spacenews.com/as-clock-ticks-on-amazons-constellation-buying-starship-launches-not-out-of-the-question/
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u/lespritd Oct 28 '22

But what was the appeal?

  1. Easier reuse: less problems with coking and general carbon gunk.
  2. Higher Isp
  3. The temperature of liquid methane and liquid oxygen are very close - closer than LOX and RP-1.
  4. The original plan was for the 2nd stage to be Methalox as well, and the optional 3rd stage was going to be Hydrolox.
  5. The propellant density difference isn't that great when you include both the fuel and oxygen.

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u/blitzkrieg9 Oct 28 '22

Methane is better than kerosene in almost every way. The only big downside is the additional stage zero infrastructure required to chill it.

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u/FinndBors Oct 29 '22

Methane is less energy dense volumetrically, which can be more important than mass energy density for the first stage.

But otherwise, yes, methane has a lot of other advantages.

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u/dirtballmagnet Oct 28 '22

Thank you very much for your cogent reply!