[ExI] The L5 Society ( was: EP and Peak oil.)

[John K Clark]

"Keith Henson" <hkeithhenson at gmail.com>

> I just finished working out the numbers for using 200 times reusable
> rockets about twice the size of a Saturn V.  To my surprise the energy
> payback works out to 15 days and it takes 3 power sats to provide the
> propellants.

That is a perfect example of a statistic that may be true but is totally
irrelevant; the fuel costs are a trivial aspect of the cost to get into
geosynchronous orbit. Right now just the launch costs would be close
to a trillion dollars per satellite, that's just to put it in the proper 
place, and that's not counting on the fact that then you've still got to
actually build the thing. You're going to have to figure out a way that 
is one hell of a lot cheaper than that and I don't see how ground 
launch from Earth can do it.

And just how "reusable" is this giant rocket going to be? Are you going to
carry a heavy heat shield all the way up to geosynchronous orbit and then
carry it all the way back down to earth again? Maybe I just get paranoid
when I hear the word "reusable"; the Space Shuttle was originally
supposed to be reusable every 2 weeks but that turned into a joke.

 John K Clark