[extropy-chat] Re: sole superpower/warfare 2003-2010 comments

[Robert J. Bradbury]

On Sat, 13 Dec 2003, Damien Broderick wrote:

> From: "Robert J. Bradbury" <bradbury at aeiveos.com>
>
> > its going to require a *lot* of Delta 4's to get that
> > much nanotube cable up to GSO.
>
> Run it up there on heavy-duty ground-based lasers? Or would development of
> that tech cost more than rockets?

I'm not so sure the development is a problem.  The lasers in both
the fusion reactor at LLNL and in the 747 the gov. is putting together
as a defensive weapon pack a pretty big punch (in terms of Joules).

However I'm not sure that would be enough to function as a source
of lift for the amount of mass that would be required.  We need some
harder numbers here in terms of the minimal mass for a cable that
could withstand normal forces (gravity, wind, etc.) and allow
micro-elevators to climb up and down the cable.  Also some figures
on the lift efficiencies of laser propulsion (it has to be really
low).  One problem is that I think most lasers systems are currently
designed to deliver heat (melt the incomings, fuse the pellets, etc.).
One would need a shift in design strategies if one wants to use them
for non-destructive propulsion purposes.

R.