Some thoughts on Mining Asteroids vs the Moon

First off I want to state that in the long term I see Asteroid Mining
and O'Neill colonies as the way to go.

> Wouldn't it be a lot more economical to get this material from a
Near
> Earth Asteroid located at about 0.25 AU from Earth?
>
> The Moon has a gravitation well and this costs money to get
materials
> on and off. We will need heavier and stronger crafts to mine there
as
> we would need doing the same on an asteroid.
>
Agreed the Moon does have a steeper gravity well than an Asteroid

> Doing the same with robotic crafts would save costs and masses
needed
> to support human life.

Robots are good for exploration, if all we want to do is to just
explore space, robotics are far more cost effective.
But what you are talking about is "Mining & refining", even on Earth
it is difficult & dirty work and equipment breaksdown.
You might be able to develop a robotic sample return system of a few
kilos, but not a full scale automated mining operation. So you are
going to need people on site to run & fix the equipment. So for each
mission, you are still going to have to budget for humans and
lifesupport.
>
> The best of all we could do that now, not having to wait on
> developments in human life support.
Wait on what? For a Closed Life Cycle System is my guess. Worst case
is that you bring all your 02 & water with you that you need, you
still may want to bring along excess water anyway, it can double as
radiation shielding.

> Betting on the Moon card only would cost humanity not only money but
> time also, years of development were nothing other is done.
>
> I would start to set out to the asteroids first and getting back to
> the Moon later when we are able to support Moon operations with
> materials and technology (especially in space construction and
> fabrication as well as tele-operation) gained at the asteroids.
>
Teleoperations from an Asteroid? The Moon is always the same
distance from Earth and I've seen postings here and in other NGs
stating that the time lag for Teleoperations on the Moon are
managable, with the Asteroids it would be lags of at best Minutes!
Besides wasn't O'Neill's original concept to use Lunar
mining/resources to built SPS & Space Colonies?

The Moon:
Disadvantages:
*1/6 gravity well, in terms of getting stuff off the Moon
*Little to no volitiles(H, N, etc, must be imported, O2 could be a by
product of lunar mining)
*Dust, that is the biggest unknown on how to effectively manage that

Advantages:
*3 days away, in terms of emergency/rescue or crew rotation
Also teleoperations, this could relieve some of the work from the crew
maybe even require few people on site, but with any kind of mining
operation you are going to need people on site to fix things when
they break down
*We have been there and know that we can work there at least for
short durrations.
*1/6 gravity We know how to mine in 1 G, most mining operations may
be easily adapted to this.
Also another big unknown is what is the minium gravity to keep people
healthy/fit? My gut feeling is that 1/6 G is better than Micro
gravity, worst case is we rotate the mining crews every 4-6months
like they do on ISS

the Asteroids:
advantages:
*rich in volitiles
*low to micro gravity, easy to get stuff off of

disadvantages:
*travel time to asteroids can take months to years and the launch
window is small and if you miss it, you have to wait years for the
next window, granted there are more asteroids out there, but the
next available one, might not be suitable or as well mapped out as
your target asteroid.
*Micro gravity, it is a know fact that longer term exposure to Zero
G/Micro gravity, is bad for humans, that is why NASA rotates the ISS
crews every 4-6months. I wish more research had gone into centripel
gravity experiments to determine what is the minium safe gravity for
human was.
Any asteroidal mission that would in total last more than 6months,
and most likely will last longer, would require some kind of spinning
spacecraft, especially for the outbound and return legs of the mission
and even when its at the Asteroid if its going to be mining it for
more than 6months. A rotating craft will add mass to it, how much I
don't know

Has anyone ever really taken a look at all, how much mass/equipment
would be required to do mining operations on either the Moon or an
Asteroid? I would really like to know.

Just my $0.02

There is only one (maybe 2) basic core reasons for humans to go
beyond LEO, That is for the establishment of space settlements or a
space based civilization. Everything else are details.

Gary Gray 11/9/2005