[ExI] Mining the Sky SL Talk I gave today

[samantha]

Adrian Tymes wrote:
> Mind if I forward this chat log + presentation to some friends?
> You touched on a lot of the points I've been touching on when
> I propose this idea.

Please, feel free.  The more these ideas circulate the better.

> 
> One thing to consider: harvesting on-site is more efficient from
> a mass budget point of view, but might not be more efficient
> from an operational point of view.  Building and launching
> refining equipment before you've confirmed that you have an
> asteroid with good materials, and that you can safely return
> the material to Earth (orbit or ground), might be more difficult
> to finance than returning an asteroid to Earth orbit *and then*
> taking care of getting equipment to process it.

Moving entire asteroids is a fair amount of delta V even with taking 
advantage of lunar gravity. And some interesting chondrites may be a bit 
hard to trim in flight to safely put them in an interesting orbit. 
Although I like this strategy for putting a lot of useful material at 
L5.  Of course unless you are on an iron asteroid or a few other rare 
types there should be enough volatiles in the rock to offset the cost of 
moving it but then you are partially processing it anyway.  And if you 
got it back to earth orbit and it was a dud then what then?  More delta 
V to dispose of it?

By scraping away at the asteroid or drilling into it I don't think it 
would take very long to estimate its value and what was worth keeping 
from processing it.   I does makes sense is to send a lot of cheap 
probes out to identify the most likely candidates and perhaps somehow 
radio tag them before putting up the heavy equipment.


   (Also, if you're
> eventually going to use most of the asteroid - say, a M-type
> where the bulk of the iron is intended for eventual use as a
> space habitat's shell - then you might as well capture it all in
> the first place.)

Perhaps for an M type. But they are relatively rare and than are many 
things very useful in the others as well.



   Also, refining equipment in orbit can be
> teleoperated from the ground more efficiently than the same
> equipment a few light minutes away.
> 

I have heard that tele-operators get a bit disoriented with more than 
few seconds of lag.

> Also, you'll need a way to confirm the mineral content of an
> asteroid you intend to mine, before you can drum up much
> financing for an operation to mine it.  Identifying a M-type is
> step one, but you'll need more precise data than that.
>

See above and the odds are pretty well known from meteorites and 
spectral analysis. Given the distribution of valuable materials common 
to various types I don't think failure to break even is that much of a 
worry IF a successful processing occurs of a sufficiently varied type. 
I would likely go first for C1, C2 chondrites for the variety of useful 
material present, especially volatiles to do more looking and stay 
longer in space.   Perhaps something that could be hollowed out as rad 
shield living space / headquarters would be an early target too.

I would worry more about the possibilites of various disastrous mishaps.


> Are you planning to give this talk elsewhere?

I don't have other targets for giving the talk at this time but I am 
open to suggestions.   In RW or VW or both.  Although my underlying 
relevant knowledge is embarrassingly thin in spots, I would be happy to 
present these ideas as best I can.

Thanks for your comments! Thanks to others for feedback as well.

- samantha