On Fri, Mar 6, 2009 at 9:09 AM, GARY ANSORGE

> 1) an OPEN ended power source and
> 2) a resource that can be cost effectively returned to Earth as a rationale for space settlement.
>
> SSPs fulfill that rationale.

I think we should maintain a very low profile on the space settlement
angle and let them come about naturally.

For example, in the context of a hundred ton per hour parts pipe line
to GEO, the lift cost to support a 1000 people is under half a percent
of that capacity. They are not independent of course.

But consider a project to build power sats entirely from the earth
using some low cost (per kg) method like this rocket and laser kludge.

It turns out that you want to build the structure out of Invar, a near
zero temp coefficient 35% nickel alloy. After a few years, the supply
of nickel becomes really tight. Even though the initial charter for
building power sats says no extra terrestrial material needed, with
that kind of presence in GEO, they are going to go after asteroids
just for the nickel.

So you get mining camps.

And while not independent, they do give people a toehold in space.

I will try to get up my slide presentation on this in a day or two.

Keith Henson

Good point, about the nickel,,,also a good reason to stress seeking nickel/iron asteroids as resource material, possibly captured in L4/L5. Those and carbonaceous asteroids are prime candidates for SSPs(raw material) as well as "mining camps". Having worked in Saudi Arabia, I'm quite familiar with construction camps in a barren wilderness. Still, as sequestered as they were, we still had everything we needed for survival, some entertainment(including smuggled video tapes and alcohol) and of course, free food.

Ah, the memories,,,

GAry 7

> Good point, about the nickel,,,also a good reason to
> stress seeking nickel/iron asteroids as resource
> material, possibly captured in L4/L5.

You mean stuff already at L4/L5? I bring the idea up
from time to time, asking if anything is known. The
general consensus seems to be "It's quite possible
something is there, but nobody really knows."

If there is, then you have the best of both worlds: the
extremely low gravity and superior composition of the
asteroids but the proximity of the Moon. The only
drawback (assuming it's there at all) I can think of is
that it could turn out to be a navigation hazard at
Lagrangia.

How difficult (or expensive) a project would it be to
find out? To rule it in or out once and for all? How
big an object could there be without us knowing about
it already?

>Good point, about the nickel,,,also a good reason to stress seeking
>nickel/iron asteroids as resource material, possibly captured in L4/L5.

Maybe if they are in the right place where relatively little delta V
is needed to get them there. But otherwise, I expect they will be
mined where found and what is wanted taken back to GEO for
fabrication into power sats. At first nickel may go all the way to
earth to be rolled into coils of sheet metal for making power sat
beams. It's hard to say. When you have earth cargo to GEO for less
than a hundred dollars a kg, it may be hard for ET materials to gain a market.

>Those and carbonaceous asteroids are prime candidates for SSPs(raw
>material) as well as "mining camps". Having worked in Saudi Arabia,
>I'm quite familiar with construction camps in a barren wilderness.
>Still, as sequestered as they were, we still had everything we
>needed for survival, some entertainment(including smuggled video
>tapes and alcohol) and of course, free food.

I suspect families are going to be shipped to GEO and later the
mining camps as soon as possible. This is a long term business, 3-4
decades at least. The number of people needed will be substantial
even if all they are doing is building and unjamming the automation.

Keith

As I recall, the Solar observation Sats that are currently making their way thru the Lagrange points in their orbit are going to be pointed back toward Earth and may observe existing objects at the Lagrange points, if any are there. One problem is that objects don't just cluster in a particular L-point, they orbit about a common gravity well, perhaps over a million mile orbit, so if they're really small(a few meters in diameter) they probably won't be detectable. If they are 300 meteres in diameter, we MIGHT detect them.

Gary 7