[extropy-chat] Space Pulleys (was Name that system)

The Avantguardian avantguardian2020 at yahoo.com
Wed Dec 20 22:43:06 UTC 2006

--- Keith Henson <hkhenson at rogers.com> wrote:
>  But
> (because the original 
> concepts required taper, people thought they had to
> go up the elevator with 
> a climber.

I do not think taper is necessary nor desirable in a
space elevator. The part that is to be tapered, the
distal portion, is actually the part that would weigh
the least tapered or not, due to its position in the
gravitational field. It would also be near the part
that is subjected to the most strain. Therefore
tensile strength by increased cross-section here would
be preferable. So rather than a taper, I would want a
flair toward the distal end.  
> This led to Rube Goldberg concepts of electric
> motors and lasers beaming up 
> power for the motors.  Plus going up slowly--which
> you have to do because 
> of power and weight problems with motors--loads the
> cable much more than 
> going up fast, not to mention that it subjects you
> to a long time in the 
> Van Allen belt.  Projected efficiencies are in the
> 1-2% range.

I agree that most of the designs for the climber are
inefficient. GEO is still within the upper layers of
the Van Allen belts so you are going to need shielding

> So I was working on a book which included space
> elevators/solar power 
> satellites last summer and came up with a way to
> effectively get step taper 
> from a constant cross section cable with a mess of
> pulleys.

I am not sure what "step-taper" is supposed to
accomplish. See above for argument against tapering. I
think a constant cross-section cable with a space
pulley is an interesting idea. It would, amongst other
things allow for maintenance of worn cable by allowing
different sections to be rotated to ground and

One thing you would have to figure out is how to
balance the torque of the distal pulley. How would you
keep the "motors" from rotating the entire housing
rather than the axle of the pulley.

> Not surprising the concept gets ignored to
> denigrated by the 
> "establishment."  :-)

I find the fact that there is an "establishment"
devoted to an unestablished technology to be
hillariously sad. 

Stuart LaForge
alt email: stuart"AT"ucla.edu

"Reality is that which, when you stop believing in it, doesn't go away." - Phillip K. Dick

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