In article , says...

A few months ago we talked about whether time to start optimising for
fuel consumption is near. (The "A conversation with Elon Musk" thread in
October)

I found the following bit of information on
https://en.wikipedia.org/wiki/SpaceX_Starship
"In November 2019 Elon Musk estimated that fuel will cost $900,000 per
launch and total launch costs could drop as low as $2 million".

So assuming that Starship does live up to Elon's estimate (which I think
is doubtful, but still a good ballpark figure), fuel costs could soon be
45% of total launch costs.

Of course, to lower the cost of access to space right now, the important
thing is to get rockets to be fully reusable and get total launch costs
around $20 per kg. But it seems that this will be done soon. Once it is
done, I think the 45% fuel costs will seem as a good place to reduce
costs further.

Elon's vision for Starship is to use Tesla solar as power for the same
Sabatier reaction that they plan to use on Mars to convert CO2 (from the
atmosphere) and H2O into O2 and CH4 (methane). In that way, Starship
propellant production would be completely carbon neutral. This is
important to him since he plans on Starship being capable of being
launched three times per day (no doubt most of those launches would be
tankers to refuel Starships in LEO).

How does this figure into costs? I'm not sure. There would certainly
be a capital investment for all that solar power, but once it's up and
running, SpaceX would not be beholden to paying for grid power anymore.

Jeff
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