[extropy-chat] Space elevator numbers III

[Keith Henson]

At 02:39 PM 2/15/2007 -0800, you wrote:
>Keith Henson wrote:
>
> > At 01:01 PM 2/15/2007 -0800, Dave wrote:
> >
> > snip
> >
> >> Not to mention the materials science and economics.
> >> I'd place the odds of having a terrestrial tether
> >> system of any sort operational within the next 20
> >> years at around one in a million.
> >
> > If we never start, the odds are worse than that.
>
>Keith, this is certainly an interesting technical challenge, but what is
>your thinking on robustness and resilience within the foreseeable
>socio-political environment?

In my view (see the EP memes and war paper) the foreseeable socio-political 
environment is largely due to a bleak future, largely due to the 
unfortunate choices we have in the way of energy.  Without something to 
brighten up the future, wars or related disturbances are going to be a big 
problem--at least till the population fall by some substantial number of 
billions.

Just *starting* on this project might be enough to damp most of the drift 
toward wars.

>More specifically, this design would seem
>to present a very high-value target to "terrorists", with multiple
>failure modes inherently lacking in contingency or fallback methods.

Putting the anchor point at Baker Island deals with most of the 
possibilities of being attacked.  Putting the anchor point on the 
Enterprise is going to inhibit a considerable number of the 
others.  Getting the major countries to invest in it would not hurt either.

The *big* problem is the cable failing and there the most likely reason is 
for it to be cut by missed space junk.  If the big pieces are cleaned up, 
and you need them for counterweight mass anyway, then it is rather unlikely 
you are going to cut all strands at once.  Brakes and grabbers on the 
pulley stations plus dumping the loads might prevent a complete 
failure.  Keeping enough cable at GEO to restore the elevator would be a 
good backup.  Cloning the elevator to other locations is also a darn good idea.

If anyone has any ideas on how to make this more robust, please speak 
up.  I am not the last reluctant to give credit.  Keith Lofstrom 
contributed the idea of the transfer station at 50 miles.

>Wouldn't this be very much a case of putting some very expensive eggs in
>a very exposed basket?

This isn't a choice really.  The only other long term, non-carbon, large 
scale (centralized) energy solution is nuclear reactors and I recently went 
into detail about the problems *that* can cause.

Keith