On Oct 2, 2:45 am, Damien Valentine wrote:
So I just got through O'Neill's "The High Frontier". There seem to be
some philosophical inconsistencies -- O'Neill claims to be promoting
individual freedoms and small-scale economies by building monolithic
power satellites and kilometer-scale orbiting cities, for instance --
but that's neither here nor there.

What really bothers me is that the entire scheme seems too much like
something out of a Rube Goldberg cartoon. "We'll build a base on the
Moon to deliver material to Earth orbit -- and we'll need at least
some mining ships scouting the asteroids for water and organics too --
which will be used to build a 3-million ton, 10,000-man space station
the size of Manhattan; then that will build 80,000-ton satellites, and
those will transmit solar power back to Earth." (He offers other
justifications for his "Islands" -- building space telescopes, for
example -- but it seems that we've achieved most of those goals
already without them.)

I suppose I want to start off by asking, "Would a Solar Power
Satellite work in the first place?" I know that the idea has gotten a
lot of flak recently; is it still viable or just hopeless?

The only way you could start off in space is to start off small. Like
Bigelow Aerospace's Sundancer module; yet it's also suffering from
that "if you build it, they will come." However, the desire for space
stations is there, and with smaller space programs like India and
China wanting their own in the next few decades, certainly the desire
for that inflatable technology will be there. O'Neill proposed that
the "small" gap would be filled by shuttles, funded by the government
and quickly scaling up to massive projects. I suspect he also figured
in economics of scale effects, as well. Only massive government
funding would be able to kickstart such a project.

Yet, his reasoning is sound - big projects do happen. However, if they
are not commercially viable (and there's no way that SPSs would be for
many many decades), they'd better be religiously significant,
militarily important or just the work of a cray rich megalomaniac.
Without that, launch costs had better be about $200 a kilo or less for
lunar/asteroid mining to become viable for supplying materials - just
to earth orbit. Building O'Neill colonies from refined lunar dirt...
unlikely. Real colonies would be built more simply (eg hollow
asteroid), be smaller, and less ambitious. From there it would be a
gradual scaling upwards. I see the first colonies as being in low
earth orbit as some kind of space hotel / servicing centre hybrid.