[ExI] Mining the Sky SL Talk I gave today
wingcat at pacbell.net
Mon Apr 26 04:28:03 UTC 2010
--- On Sun, 4/25/10, samantha <sjatkins at mac.com> wrote:
> 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.
Exactly. Even if you yourself can't use it all, you know the
rest will be useful without too much processing, with a mostly
iron asteroid. That is not as true of the other types.
> 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
Yes, but that's gambling on the processing working in order
to get the desired amount and type of volatiles.
> And if you got it back to earth orbit and it
> was a dud then what then? More delta V to dispose of
This is why surveys must be done ahead of time, or failing
that, on site. But survey equipment is less massive than
> 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
Or, better yet, if you can somehow find a way to do it with
telescopes in Earth orbit, or even ground-based Earth
telescopes. Such a survey is within the range of what one
of NASA's Centennial Challenges could support. I've
suggested it to them, but I doubt the suggestion went far
beyond the automated inbox.
> Perhaps for an M type. But they are relatively rare and
> than are many things very useful in the others as well.
You have to start somewhere. Any actual effort to do this
will, by necessity, start processing 1 asteroid before any
others. (Survey of multiple asteroids may happen first,
but serious processing won't happen everywhere first.)
> See above and the odds are pretty well known from
> meteorites and spectral analysis.
I've been hunting for material on that - not just "this
albedo means this type of asteroid", but how specifically
one can tell what % of an asteroid is platinum (or at
least get a good estimate of the %), for example. How
would one survey for a platinum-group-rich target?
> Perhaps something that could be
> hollowed out as rad shield living space / headquarters would
> be an early target too.
That's another reason I suggest a M type: after the other
metals are taken out, melt down and spin up the iron to make
a startup space colony shell.
> I would worry more about the possibilites of various
> disastrous mishaps.
Of course. Those would need to be listed out. Perhaps the
next version of your talk can do so, and address them?
Among the ones I can see:
* Finding out that the target NEO is a dud (specifically,
not compatible with the processing equipment you sent up)
after you get there. Solution: survey as best you can
before you send anything to the NEO itself, and design
the mission to require as little processing as possible
before an extensive on-site survey (done while the NEO
is en route to Earth) can be performed.
* Moving a NEO to Earth orbit messes up and you create an
Earth impacter. Solution: change the orbit slowly.
Encourage third party observations to catch errors
(you're moving an asteroid in open space; this is very
hard to hide, especially if you're not trying to hide).
Propulsion systems that are difficult to entirely break,
such as solar sails, may be best. Plot the orbit every
day; if the margin of error becomes unacceptable, shift
orbit to ditch the asteroid.
* Moving things from Earth orbit down to the ground
messes up, as above. Problem here is, you want Earth
impacters - to recover platinum, et al, to sell on the
open market to recover the investment. (At least, that
is the strategy I recommend for financing the first few
asteroid captures, and thus starting up serious space
industrialization.) Keep the individual chunks small,
and aim for open water (both to avoid damage, and to
avoid national legal claims - you want to pick up the
artificial meteor as "salvage", and have ships in
position to do so - and keep others away long enough to
do so - the moment it splashes down).
* Legal challenges, especially related to current
international space treaties. Again, make sure
anything you bring down to Earth comes down in
international waters, so no nation needs to make an
opinion on whether the asteroid is owned in space;
rather, chunks of it enter into ownership while in
the Earth's atmosphere. (Anyone contesting ownership
because the object came from space, can be referred to
legal precedent regarding ownership of meteorites.)
Few enough players will be able to actually put
anything into space that legal enforcement up there
will hopefully be irrelevant for a while anyway, and
if it really does become a concern, the processing
equipment can likely be repurposed for self-defense -
crude, but more than enough to handle unarmed
interlopers. (If they come back armed - you should
be able to more than recover investment by then, and
so have the resources to go claim another asteroid.)
* Protests from people convinced you're inevitably going
to have one of the above catastrophes. The real
problem is, only a minority will actually have thought
through and believe what they claim; most of them will
be paid to protest, or roused by feel-good sound bites,
and either way be made unassailable by logic and
evidence. (See many of the tactics employed in the
recent health care debate for a prelude.) I'm not sure
what to do about this, aside from tapping into the
wellspring of hope and developing an infrastructure
that will let the average person eventually get into
space - but since there are large sums of money in
small numbers of hands involved (whoever runs this
operation is likely to get rich), this may be difficult
* Market collapse, after you sell several kilotons of
platinum. Solution: this will hopefully be much
cheaper to do the second time. Also, you can target a
NEO with minerals which the first NEO did not collapse
the market for. (As you noted, there are many
different types of rocks out there.) Also, once the
first rock starts making a place for people to go to
in space, there may start to be a viable market for
selling resources (especially volatiles) in space
(which market does not exist today, no matter what
many enthusiasts wish). That said, even several
kilotons of platinum might not collapse the market
> 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.
Just a thought, and it might be a long shot to get in as a
speaker without serious professional credentials (then again,
they might not have any speakers on this topic with said
credentials, so you might have a chance):
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