[ExI] economic parableRe: Sudden outbreak of democracy baffles US pundits

hkhenson 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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