[ExI] Resource extraction from NEOs/was Re: Power satellites

[Dan]

--- On Fri, 5/1/09, ben <benboc at lineone.net> wrote:
> Dan <dan_ust at yahoo.com> wrote:
>> I would say: lunar or (inclusive) other off-world
>> materials.  Plenty of NEOs to mine.
>> Of course, to be sure, there is far less data on their
>> composition and structure -- as
>> well as many other unknowns regarding them.
> 
> OK, I'm way behind on this list, so someone may have asked
> this already, but I'm interested in the issue of NEOs as a
> source of raw materials, and whether this is even remotely
> feasible.

Well, I think the two big problems with NEOs as a source of raw materials is finding out what they're composed of and their overall structure.  My guess is they probably fall into a few classes and each member of the class differs in ways that would mean one would have to do some prospecting...  However, things are not too different with Luna -- save that there's lots more data.  But, still, no one has done a lot of prospecting and from only a handful of sites have samples been taken.  The rest is guess and surmise based on the samples and remote sensing.
 
> I'm thinking NEOs, like most things in space, go fast,
> relative to the earth.  Really fast.  Getting to
> them, extracting useful resources and getting back with
> those resources isn't at all like drilling for oil or
> digging up metal ore here on earth.

The difference: no atmosphere and extremely low gravity.  Once you're above the Earth's atmosphere, as the saying does, you're halfway to anywhere in the solar system.  Also, the usual proposal for lunar extraction involves using mass drivers -- not taking off with a space ship loaded with ore.  (I actually don't see why a lot of processing can't be done on location on Luna -- or on an asteroid.)  No reason the same can't be done with a NEO.

Of course, rendezvousing with a NEO involves problems, but there are a few in fairly regular orbits.  Soem are Earth-crossers, so they come closer, but then, yes, the speeds are high.  I don't think it's impossible -- just a little harder than lunar prospecting and landing.  (Partly because the latter has been done before, partly because Luna's orbit/positions are really well mapped out, and partly because Luna is a really big target compared with the average NEO.)

> I suspect it's
> possible that the energy required to get there and get the
> hydrocarbons or ores or whatever back, would far outweigh
> their value.

I actually think you're wrong here, but this is my guess.  First off, regarding volatiles, Luna has none (or so it seems) and hauling them up from Earth would be very expensive.  Mass drivering (word?) them off a NEO would seem -- and this my guess - fairly low cost.  (Prospecting the NEO, mining it, and placing a mass driver on it would seem to me to be where the large costs would in the whole operation.  But Luna has similar costs -- it ain't free.)  They could be launched into a solar orbit to be caught at whatever desire location and the mass driver could be solar powered.
 
> Anybody know some hard facts about this?

Well, it's speculation for now.  The only sure numbers we have are past and current prices on hauling stuff up the gravity well.

Regards,

Dan