[ExI] Power satellites

Keith Henson hkeithhenson at gmail.com
Fri Apr 24 19:45:08 UTC 2009

On Fri, Apr 24, 2009 at 9:44 AM, John K Clark <jonkc at bellsouth.net> wrote:
> "Keith Henson" <hkeithhenson at gmail.com>
>> Like all elevator proposals it suffers from the problem that we don't
>> have the nanotube cable yet, but if we did his estimate isn't out of
>> bounds.
> So let's see, we don't know how to build practical power satellites but if
> we had something else that we know even less how to build then they would be
> dirt cheap.

It's a straight forwards analysis.  I worked it out here:

>And on the basis of this "financial analysis" you expect people
> to invest in the venture.

Invest in what venture?  There is no space elevator venture possible
until and unless we get the cable.  I clearly stated that.

>Recent events have shown that bankers aren't
> exactly rocket scientists, but they're not THAT dumb.

Bankers loaned money, several times as much as would be needed for a
full scale power sat project, to people who could not pay it back.

I would appreciate you distinguishing between perpetual motion
machines and space elevators.  The first violates our understanding of
physics and takes extraordinary proof.  Space elevators do not violate
physics, they just take engineering development.

Rockets, laser propulsion or space elevators, none of them violate
physics.  Rockets going into space went from being considered
impossible by most people early in the last century to landing on the
moon by the mid 60s.  Space elevator physics was understood by the mid
60s and there was even earlier work by the Russians.  There was a
great deal of work on laser propulsion in the 70s which was finally
shelved because efficient lasers were not available.  That has changed
with the advent of solid state lasers to the point a system can be
analyzed and even made into a business proposal.

In that context, moving cable space elevators need to be considered as
a *risk.*  There is massive incentive and plenty of current work to
develop extremely strong nanotube fibers and cables for a huge range
of products.  A large propulsion laser used part time to clean up
space junk would massively reduced the second biggest space elevator
problem.  A power satellite project based on rockets and lasers
transport could be abruptly undercut by a space elevator.

If you don't think this can be a problem, look up what happened to
Iridium.  http://en.wikipedia.org/wiki/Iridium_Satellite_LLC#History


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