Re: Uses of Bulk Nano Materials (was beanstalks)

From: N:dlzc D:aol T:com \(dlzc\) (net_at_nospam.com)
Date: 06/11/04 

Date: Fri, 11 Jun 2004 16:43:41 -0700

Dear Ian Stirling:

"Ian Stirling" <root@mauve.demon.co.uk> wrote in message
news:40c9de61$0$534$ed2619ec@ptn-nntp-reader02.plus.net...
> In sci.space.policy "N:dlzc D:aol T:com \(dlzc\)" <N: dlzc1 D:cox
T:net@nospam.com> wrote:
...
> >> Kevlar was just an example, picked out of the air, of a current
material
> >> that would be suitable from a strength point of view.
> >> There are quite a few others that may be suitable, if the conductivity
> >> of nanotube stuff is found to be a problem.
> >
> > The issues of zero thermal expansion, non conductivity, resistance to
ozone
> > (and monatomic oxygen), and light is a null set of members.
Purportedly
> > carbon nanotubes can be made non-conductive. Whether this can be done
in
> > bulk...
>
> Why zero thermal expansion?

The stranding exposed to the Sun will get longer, and the other side get
shorter. This will increase internal stresses, as the cool side will carry
the majority of the load.

As areas warm, the entire tether will grow longer, and the object
tensioning the cables will move away from the Earth and retrograde. The as
it cools, the tensioning object will be drawn in, and precess. A few tens
of feet, but the loading on the tethers will have to be adjusted
dynamically, to keep the loading the same. Making it dynamic will allow
you to reel in or play out tether to compensate for "global" heating and
cooling.

> And the bottom 100Km/miles could be almost trivially replaced anyway,
> it's of negligable mass compared to the rest, and one car could easily
> take it up, lower a new one, and unhook the old one.

As long as you have a lot of redundancy, yes. The support car must not
need the replaced cable to stay up, and the balance of the cables above
must be able to support n+1 below.

David A. Smith

Relevant Pages

  • Re: Uses of Bulk Nano Materials (was beanstalks)
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  • Re: Uses of Bulk Nano Materials (was beanstalks)
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