Stopping By

> > Moving the asteroids to a near Earth orbit presents many problems.
> > First the combined mass of all the asteroids is only 1/30th the mass
> > of Earth's moon. So we don't have nearly enough material to start
> > with,
> >
> Surely you jest. Each 100m diameter is, roughly, enough shielding for
> a Kalpana One sized orbital settlement (http://alglobus.net/NASAwork/papers/2007KalpanaOne.pdf
> -- 5,000 people). Shielding is most of the mass of orbital
> settlements. If memory serves there are around 200,000 such asteroids
> in Near Earth Orbit alone. So, very very roughly, there's enough for
> at least a billion people to live in space. That number is a very
> loose ***lower*** bound.
>
> Yes, there are more materials on the Moon than in the NEOs. Exactly
> what application do you think would require more than 3% of the entire
> mass of the Moon?

We are not talking about the same things, his proposal was moving all asteroids into a near Earth orbit, combining them, and terraforming it as a new second Earth. That proposal is what I was analyzing. I completely agree with using NEOs for building habitats.

> > it would make more sense to add the mass to Mars if we are going
> > that route. But the other problem is moving 100's of thousands of
> > small to large asteroids into a near earth orbit will be very
> > energetically costly and leave the newly forming body pretty useless
> > until you are done as you are continuously bombarding it with fresh
> > material.
> >
> I don't think anyone has ever seriously proposed building new
> planets. That is entirely unnecessary and an awful lot of work. The
> same material can get you far, far, far more livable area in rotating
> orbital settlements. Why? Because 3D bodies require a lot more
> material than 2D shells.

Well, that's why I was trying to show it as not a good idea.
Brooks