[ExI] economic parableRe: Sudden outbreak of democracy baffles US pundits
hkhenson at rogers.com
Thu Oct 9 05:19:21 UTC 2008
At 03:54 PM 10/8/2008, Stuart wrote:
>--- On Wed, 10/8/08, hkhenson <hkhenson at rogers.com> wrote:
> > Having been here when I have been talking about the space
> > based solar
> > power project I am sure you can appreciate just how hard it
> > is to
> > work up interest in producing real value.
> > I have yet to get someone to go over the numbers. Or if
> > they have,
> > they didn't tell me about it.
>I did and I agree with your numbers.
That's not good. At least one of those number is incorrect.
>They are just too big and scary for even charitable billionaires to
>stomach. The only thing close to that mass that we have successfully
>put into space is the ISS and everybody hates it. Maybe you could
>figure out a way to recycle that monstrousity into a powersat.
The big economic factor is the lift to GEO. There are at least three
ways to get the cost below the critical $100/kg figure. A moving
cable space elevator would do it. That seems to be the lowest cost,
capital expense plus 15 cents for the energy. We don't have the cable yet.
The next best seems to be my pop up an push version. The problem is
the laser which at $10 a watt would run some $80 billion. Still, it
lifts 1 million tons, a billion kg to GEO at a yearly cost of $8
billion plus the rocket lift to 260 miles. The whole cost looks to
be maybe $50/kg.
The most expensive approach that still gets in under $100/kg involves
a space elevator that ends about an earth radius from the
surface. The lower stress means it can be constructed of existing
materials. Sub orbital rockets go up to the end of the tether, latch
on and are wenched up to GEO. I am told it needs 24% of the energy
to go into LEO, but have not independently calculated it.
At the conference in Orlando Charles Miller mentioned to me how he
thought the project could be funded. In retrospect his idea is
obvious. There seems to be convergence on a method to finance the project.
I don't want to make it public before we are sure the numbers we set
are enough to get the job done.
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