Re: Asteroid mining question

Wasn't it Jack Tingle who wrote:

>I was never sure where that came from. Relatively easy on a 
>per-pound-of -asteroid basis, and relatively easy period are not the 
>same thing. We can currently handle things around the earth on the 
>order (optimistically) of a hundred tons. (Skylab was 77 tons. Yes, I 
>know ... ISS is bigger ... no more Saturn V's ... shuttle is almost 
>shot ... make it in pieces ... shuttle derived big boosters ... 
>yadayadayda ... Bugger that. A hundred tons.)

But getting a hundred tons into low Earth orbit is a completely 
different prospect to getting a hundred tons from the asteroid belt into 
Earth orbit.

Probes that we've sent to the asteroid belt and beyond have had to use 
at least one gravity assist swingby to achieve the required velocity. 
Since there's no friction in space, reducing the velocity would need to 
use the same trick. Note that each swingby adds something like a year to 
the duration of the trip.

-- 
Mike Williams
Gentleman of Leisure