Mining Asteroids

> With a rotary launcher slight changes in friction as the pellets
> go down the tube could make aiming very difficult.

That shouldn't be a problem for my scheme, because the stuff isn't
being launched down the tube. It's trickling down the tube,
accumulating at the bottom, and then being released by a trapdoor
when you want thrust. I figure on having a rather long tether, so
the tip velocity can be high even while the angular velocity is
fairly low. Low angular velocity means that the time precision for
the release isn't very stringent.

> The SSPS concept could pay for any amount of space development.<

Once we have our mining systems, processing facilities, and a colony
big enough to make everything, SPSS certainly could be enough to pay
the ongoing earth-based costs. But I'm not convinced that the up-
front costs are going to favor space-based solar over ground-based
early on. Ground-based solar energy doesn't require any more space
than we already have pavement on.

> There are many important materials which are rare or inaccesable
> on Earth, and which could be obtained for lower cost as a 'side
> line' while peopel are mining for more common and useful materials.

Platinum-group metals, definitely. What else?

> Any material minned can be sent to pretty much any position on
> earth quickly and cheeply. Look up the logstics of building a
> bridge. The pieces of metal are V E R Y L A R G E and it
> is horribly difficult to ship them across country. Build them in
> space though, and you can just sofft-drop them into the nearest
> lake or corn field.

I like the idea. How does the soft-dropping work? How much easier
is it to fish them out of the nearest lake than to haul them cross-
country?

> Sun Shield system. Put enough very large solar sails betweeen the
> earth and the sun and you can affect how much energy reaches
> earth, and hence regulate Earth's tempreature - in theory enabling
> you to reduce, stop or even reverse global warming.

That's another one I've contemplated before, but I forgot to put it
on the list this time.