Marrying asteroid defense and asteroid mining

I was just worried. Rocks thrown around by the mass driver should not take a round and hit someone on the head from the back, like we see in some of the funny movies : - )

I was just wondering whether any calculation has been done for a real asteroid, with known orbit, how we would deal with it if it were to head for Earth, or if we were to attempt to capture it? My fear is that it may not be as easy as it may appear, these bodies are moving at fantastic velocities. Our own Earth moves at 29.7 Km/s! If we were to get an advanced warning of one year say, nothing short of multiple nuclear attacks would divert a sizeable asteroid.

Regards
Selvaraj

From: Combs, Mike

From: spacesettlers@yahoogroups.com
[mailto:spacesettlers@yahoogroups.com] On Behalf Of sraj

> Is it not possible to have a mass driver that vapourises all
> the stuff and releases them as rocket exhaust? Much more desirable
> in the long run, so as to avoid polluting Solar space with
> unnecessary flying objects.

The closest I've ever heard to what you're saying was two comments: One
that if we were to use liquid oxygen as reaction mass, it would vaporize
on release and thus pose no hazard. Another was that even if using
regolith for reaction mass, one might place an electric charge on it
prior to ejection, such that each particle would repel every other
particle, so that the debris would finely disperse rather than
continuing to orbit as a dense swarm.

I would say that if Earth was threatened with a major asteroid strike,
nobody would fuss about creating a bit of space debris. The debris
concern is one for ongoing continuous mass driver operations over many
years or decades, not one for a single, desperate mission to an asteroid
to avert a global disaster. It might not even be a concern for a
fledgling High Frontier industry trying to get a start.

> Probably a suitable Nuclear engine could do the job.

Now I'm confused. Are we talking about replacing the mass driver engine
with a nuclear engine, or are will still seeking ways to mitigate the
debris problem from using solid reaction mass in mass drivers?

Regards,

Mike Combs