Digest Number 1285

> The only way we'll find out whether Mars or the asteroids are best
> is by trying each out.

How far does that principle extend? Do we need to try out Alpha
Centauri before we can figure out that asteroid or lunar material in
HEO is a better way to start?

We can do some calculations of travel time and launch costs, and there
are some spectroscopic observations of what's there.