How many SPSes for $87 billion ?

> > Speaking of energy I'd be interested to know what are the lists
> opinions on
> > Zaslavsky's energy towers: http://www2.ari.net/zwirnm/arubot.htm
>
> Thanks for the link. I recall seeing this proposal a few years ago
> and thought it was interesting.

Same here, I was wondering if anything new was happening about it... sounds
like it has a lot of potential but I agree it's probably far from being
commercially mature or we would have heard more about it...

*big snip

>
> The problem is that we have the tech to build SPS and Habitats now,
> while self-replicating machines are still impossible, thus they are
> the Dues ex Machina in our dialogue.

They aren't that far at all actually... a 1980 feasibility study from NASA
http://www.islandone.org/MMSG/aasm/
was putting them within reach of entirely existing (at the time)
conventional technology, so by now they're in fact more technically feasible
than SPS and habitats, once again the issue is not technology, but
economical interests and politics. But the big advantage from our pov of
those systems is that they require a fraction of the initial investment...
all that program needed was approximately four Apollo missions worth of
start up! Breadcrumbs compared to building SPS from here, and it would
become able to build an SPS in a couple of decades at a tiny fraction of the
cost of sending up and assembly the thing from earth... :)
If Carter had given the go ahead for that program back when it was proposed,
today we would have 1,024 plants in place on the moon with a combined
productivity of 102,400 tons/year by the most conservative estimates in that
report, and most importantly since the system would still be growing
exponentially that would continue to double every two years.
SPSs would be that much more close!

> The beauty of this list and of democracy is that we can all advocate
> for our favored positions. I wonder if anyone has incorporated a non-
> profit research corporation to solicit donations to be used for self-
> replicating research.

I would be very interested to know that too... sounds like the kind of job
I'd apply for tomorrow... ;)

> As for an institutional goal, for SSI and similar organizations, I
> think that they should stick to their knitting and let others devote
> resources to researching self-replicating machines and then we can
> use them when they are fully developed. We don't need to invent
> everything, we just need to figure out how to build and pay for our
> desired orbital infrastructure using the tools on hand.

Agree completely, my point was that self replicating systems IMHO are
exactly that: the best way to build and pay for our desired orbital
infrastructure using the tools on hand! :)

Cheers,

Claudio