Asteroid use

"Combs, Mike" wrote:

From:
Al Globus [
mailto:aglobus@...
]

Recent advances in superconducting materials may make active shieldingsignificantly more attractive than at the time (1970's) the Ames studieswere conducted. I haven't looked into this closely, but I do knowthat there are some projects in development to use magnetic fields workingwith the solar wind for propulsion. Shielding should be easier than
propulsion since you don't need as much control.
Yes,I know that Geoffery Landis feels it's time to give active shielding asecond look. Still, I feel that one advantage of passive shieldingis
that
onecan't have a systems or power failure in a slag wall. But I mustadmit that for an engine-equipped habitat which is intended to go places,reducing the habitat mass by around 80-90% would be a significant advantage.

Regards,
Mike Combs

Al Globus
aglobus@..., (650) 604-4404
http://www.nas.nasa.gov/~globus/home.html
The dinosaurs weren't spacefaring. We are. I don't think that's an accident.
Maybe we are life's taxi to the stars.
I think we should:
1. Devote half of NASA's budget ($7 billion) to reaching NASA's 2020goal of
reducing launch costs to Low-Earth-Orbit to $220/kg with a 0.01% failurerate.
This should enable space tourism. The resulting orbital hotels willneed to
develop efficient orbital life support and other necessary technologies.
2. Build orbital space colonies. The materials in the largest asteroidare
sufficient for orbital colonies with a combined surface area about500 times
greater than Earth's. Eros alone could make over ten thousand spacecolonies,
each with about about 10 square kilometers of 1g living area.
3. After a few generations of orbital living, people won't need theircolony
to be near Sol. Then small groups of colonies with populations in the
tens-of-thousands can set out on multi-decade journeys to nearbystars.
Except the launch goals, none of this is even a little bit official.