Asteroid Mining

--- In spacesettlers@yahoogroups.com, "Dan Wylie-Sears"
> > If you see nothing to export from the moon, I'm afraid there is
> > not much more to export from near earth asteroids.
>
> Asteroids have all the elements present on the moon, plus many
> more. Iron and oxygen are abundant everywhere, for example. But
> the moon has negligible amounts of carbon, nitrogen, and
hydrogen.
> Carbon makes everything. If you want to make kevlar in space, you
> can't do it on the moon without transmutation of elements.
>
> > And they are moving. Some may come nearer earth than the moon.
> > But not for long.
>
> "Near" in space is measured three ways: light lag, travel time,
and
> delta-vee. Light lag matters for remote operation of machinery.
> Travel time matters for how much return on investment is required
at
> any interest rate, and for how readily plans can be changed.
Delta-
> vee matters *exponentially* for how hard and expensive it is to
get
> somewhere and to bring payloads back by rocket. Interest rates
are
> exponential too, but with doubling times of decades: longer than
> most projects take to pay off. Delta-vee, on the other hand,
> doubles the required amount of rocket fuel over ranges comparable
to
> one stage to the next of a multi-stage rocket. (The actual
numbers
> vary according to the type of rocket, particularly the exhaust
> velocity.)
>
> In terms of delta-vee, there are pretty much always asteroids
nearer
> than the moon.
>
> > If something goes wrong on the moon, you are a fixed distance
from
> > earth. On a near-earth asteroid, you are moving further and
> further
> > away.
>
> The idea is to bring the asteroid to earth orbit, with systems
> requiring little or no human presence. Then the bulk of the
person-
> hours are closer than the moon.

If it works.

Too all it takes is some politician screaming about how the robots
guiding the asteroid might be misprogrammed.

Picture some asteroid hurtling out of the sky straight for a
helpless city. Even terrorists in space.

Your physics are probably okay. But people factors are important
too.

Do you want an asteroid guided by systems designed by the lowest
bidder?

Rick Brooks
All it takes is a few scare-mongers and many people will be terrified
at the thought of massive asteroids in near earth orbit