Spinning [WAS] Island One, Two and Three

From: sardonius2000 [mailto:sardonius2000@...]

"Hi Dave, have you read the book "Mining The Sky" by JOHN S. LEWIS"

One of my favourite books! But my take on it, and everything else Lewis has
written, is that if you look at the best, most optimistic examples of what
we could do with the Moon, or Mars, the NEOs are still, by far, the best
choice.

"On the Moon we might build Lunar solar power stations ..."

Which, as Lewis points out, will only work half the time. 14 Earth-days of
light, followed by another 14 Earth-days of dark, no matter what part of the
Moon you put the solar panels on.

Unless you're referring to Solar Power Satellites (SPS), put into GEO? In
that case, the NEOs still provide a far greater variety of materials to work
with, and avoid the penalty of boosting the materials out of a major gravity
well.

"and process the regolith for helium-3 to use as a fuel in fusion reactors"

Which no one has ever created yet, and no one knows how long it'll take to
do so. *IF* (and it's still a really big *IF*) someone ever gets some sort
of affordable fusion system going, we can re-visit the issue. If that ever
happens, the He3 in the regolith might be one of the most valuable things we
know of. Until then, it's worthless.

"and on Mars we could build a very interesting device called a sky hook"

Some folks use the term "skyhook" to refer to a `space elevator', attached
to the surface. Some others refer to a spinning tether. Either way, it can
be used on/near the Earth; we don't have to go to Mars to do it. Look at the
work of Dr. Bradley Edwards. Read his book, `The Space Elevator'. Or, you
can check out the various YahooGroups discussing either topic. Mars is
actually more difficult to use *either* plan on, because of the very low
orbit of it's `moons'.

Whether we get into space via a `space elevator', a RLV, or any combination,
the resources of Mars, and/or the Main Belt asteroids, could be centuries
away. The Moon, so far, doesn't offer anything we can use. The NEOs can
provide all we could possibly use for generations.

Dave
"Is a planetary surface the right place for an expanding technological
civilization?" Dr. Gerard K. O'Neill