New here, asteroids prefered

crookedmancreations wrote:

> > Not true. The moon has gravity, which may be useful for some things
> > (and yes, eventually we'll be able to produce artificial gravity, but
> > not right away).
>
> True, the moon has gravity, about 1/6 of Earth. However, this can be
> seen as more a liability than a benefit.

Or it can be seen as more a benefit than a liability. Depends on your
attitude, I guess. :) As I said, it may be useful for some things; and
for other things, zero-G will be useful. Eventually orbital facilities
are clearly the way to go, but we're talking about INITIAL steps here,
where our orbital facilities will not have artificial gravity.

> To date in our extraterrestrial
> experience it's the ABSENCE of gravity that has produced commercial
> applications.

That's committing two logical errors:

1. There are no commercial applications in space that care about gravity
at all (satellites would work just fine in gravity; it's their position
that matters, not the micro-G). All that hype about perfect crystals,
pharmaceuticals, etc. has not led to any actual commercialization as far
as I'm aware.

2. Even if there were such applications, you'd be confusing cause and
effect. Our "extraterrestrial" capability is limited to LEO, and we
lack artificial gravity capability (as noted above). So if we did have
any commercial applications, they would by necessity be zero-G ones.

> And let us not kid ourselves: it's commercial profits and
> potential profits that will, in the final analysis, get us and keep us
> off the planet.

Very true.

> Some of the fields of study yielding, or about to yield,
> results with a high probability of commercial applications that require
> an environment of microgravity include:
> ...

[A bunch of hypothetical stuff that has never been proven and, in my
opinion, have a low probability rather than a high one.]

> And on the subject of 'artificial gravity',
> who knows if or when that might be achieved

Indeed (though it's a matter of "when," not "if").

> Herding asteroids may be an 'assertion', but you've got your time scale
> fantastically skewed:
> "people can travel between the stars" and "powerful bombs can be made
> with antimatter,"
> If we're not herding asteroids inside 20 years, we're probably going to
> be in trouble resource and energy wise, whereas your examples are
> possibly centuries away (aside from generation ships)

Perhaps I did exaggerate to make a point, but I think you've done the
same thing; we won't be herding asteroids in 20 years. 50 years,
perhaps. Or perhaps it'll be closer to 100.

> I can see a thriving habitat/Earth economy easily enough, but, unless we
> DO herd, harvest and utilize the asteroidal resources available to us I
> don't see there being sufficient materials to effect any kind of
> 'economy' on the moon- what do you have to sell, or what potential can
> you offer to prospective manufacturers to set up shop there?

Are you kidding? Metals, volatiles (including H2 and O2), bulk mass for
radiation shielding... let's not kid ourselves, space is mostly vast
stretches of emptiness, full of plenty of solar energy (at least in the
inner solar system) but not much else. Sources of materials are
valuable, and hauling them up from Earth is dangerously close to
impractical.

> Then
> there's the factor of getting those products to their markets: 1/6 g,
> while miniscule in comparison to Earths, will still require significant
> use of fuel (or a significant outlay for a linear accelerator, skyhook,
> etc.)- much more of an expense than would be incurred by shipping from a
> zero g habitat.

If you could wave a magic wand and have a zero G habitat appear (poof!),
yes. But in that case we should wave the same wand and have the linear
accelerator appear on the Moon.

Barring such a magic wand, you have to compare the expense and
difficulty of building the mass launcher on the Moon, to building a
space habitat. The latter is probably about 100 times harder. (Indeed,
the serious folks who have studied this -- e.g., O'Neill -- quickly
concluded that you need the former to build the latter.)

> Where do you get your building materials for your
> settlements (unless you utilize tunnels beneath the surface sealed
> somehow, or Bigelow style blowup modules or domes)?

Indeed, either of those are good options. The Moon is a giant ball of
building materials; there's no shortage of good options. (Others
include building inside a lava tube, or building them out of bricks or
metal and covering them with regolith.)

> How do you live
> there- volatiles and water (no one knows how much ice is at the poles or
> if it will prove accessible, and any volatiles delivered via cometary or
> asteroidal strikes will necessarily be widely scattered by impact) will
> need to be imported though as you say there are plenty of oxides.

We know as much about lunar water as we do about asteroidal water. And
we know there's a lot of it: both concentrated at the poles, and spread
thinly but uniformly over the surface.

> All together, a scenario of orbiting (or free flying) habitats and
> asteroidal capture and harvest makes much more sense.

Long-term yes, but not initially.

Best,
- Joe