[AR] Re: thinking big once more
- From: Dave McMillan <skyefire@xxxxxxxxxxxx>
- To: arocket@xxxxxxxxxxxxx
- Date: Wed, 28 Sep 2016 17:41:57 -0400
On 9/28/2016 12:23 PM, John Dom wrote:
I still have not found the time to listen to the last half hour of his
presentation and I hope he’ll come up with who he believes is going to
invest in/pay for such a colossus project.
He doesn't. Elon's plan is to essentially come up with, at most,
the proof-of-concept prototypes for the ICT, and maybe fly one to Mars
and back. He's gambling that, if he gets that far, and demonstrates
that it is technically feasible to send that kind of
vehicle/cargo/passenger mass to Mars and land it, at something even
remotely close to his predicted price (which probably depends on the
very large economies-of-scale he was projecting), enough people with
means will become interested to fund the first expedition.
In a similar vein, he did not address the issues of building a city
on Mars, because that's not his thing -- he is, at most, trying to build
the railroad (and hopefully get paid to carry the freight). Right now,
assuming things go well for SpaceX in general, he can *probably* swing
building the first prototype vehicle (though not on the timeline he laid
out).
Also note he's not betting the entire company on this as a single
gambit, either -- the ICT is designed to be able to fulfill other use
cases, both near-Earth and beyond Mars, and I'd bet there are other uses
in mind for Raptor as well. This is classic Elon -- much like how he
essentially managed to get his Earth-to-orbit customers to pay for his
research into recovering the first stage of the F9.
But he can proves futile all the false memes/arguments spread (incl.
on AR) to explain why NASA &/or private enterprise have been sitting
on their hands for 6 decades with building heavy launchers. Who needs
them? was typed for AR so often, the future is small launchers (??).
Elon’s presentation could have been made in 1970 and we could have
been dining on Mars in 2016.
SLS (and yes, even the Saturn 5) are examples of doing heavy lift
the wrong way -- or at least, the unsustainable, economically nonviable
way. *If* SpaceX can pull this off (which is an open question, but I
didn't see any obvious technological showstoppers (large speed bumps,
yes) in the presentation), it'll be an example of doing heavy lift in a
sustainable fashion.
Just dreaming, I’d prefer the Mars ships to be built in Earth orbit
like, say, the Star Trek ships or the ones in the von Braun Mars movie
(fifties). Many times the size of the ISS.
Elon doesn't seem to have any fear of Earth Orbit Rendezvous and/or
assembly. But it looks like doing a surface-to-surface ship was what
produced the best case, economically, in SpaceX's analysis. Everything
in the plan is based around getting a *lot* of flights out of each
vehicle. And there's an argument to be made for lifting all your
complex hardware (including people) in one go, and only transferring
your propellant on-orbit.
> Even using F-1 engines you would need about 20.
Right, meaning Elon maybe should go for future engines already with a
single engine thrust equalling say 4 to 5 F1’s.
I doubt anyone has done a serious trade study of "a lot of small
but reliable engines that don't have much problem running alongside each
other" and "a few really big engines". Well, except probably SpaceX.
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