The problem of mining asteroids was re-triggered in my mind by a post to Planetary Resources <http://www.planetaryresources.com/> wondering how asteroids could be mined. I replied with something similar to what is below and put a link in my reply to my blog and the presentation. I checked back a couple of days later and noticed that ALL the postings that had any technical value (which meant that they also contained links to more information) had been deleted. Everything left was bland ramblings. Obviously somebody at Planetary Resources doesn’t links in postings or doesn’t like technical discussion which kills any reason I would ever post there again. I got the message, “Send money not technical help”.
Planetary Resources puzzles me. Why are they focusing on telescopes? There is only a limited amount of information that can be gathered by an optical telescope even if you have a thousand of them looking. We already have a classification system for many of the asteroids that have been detected. We have the orbital information. What we are lacking is knowledge about what is hidden under the outside layer. No amount of passive observing is going to obtain that knowledge. To me the obvious first step is to go out to an asteroid with a good delta V and start digging through it. Why waste time and money on a fleet of small telescopes in earth orbit.
Water is the primary boot strap material required to build a manufacturing base in space (see previous blog on ISDC presentation). So the first goal should be to obtain large amounts of water.
- Select several non-nickel/iron asteroids.
- Bag the asteroids.
- Heat the bag.
- Vent the vapor to another bag.
- Cool the vapor to a liquid or solid state in the separate attached bag.
- Transport the distilled products back to the manufacturing site or use in place.
- Manufacture larger bags using distilled products.
- Repeat with larger and larger asteroids.
The tricky part is using the distilled products to make more bags since what products are available will not be known until the asteroid is distilled. Heating the bag is done by sunlight. Cooling the receiver is done by removing sunlight or using the type of refrigeration material described in my ISDC presentation. Multilayer films that absorb heat/sunlight on one side (outside) and reflect it on the other (inside) would be used to bag the asteroid. These materials can be quite strong and efficient. There would need to be some sort of active positioning system to keep the spinning asteroid out of contact with the inflated bag and a way of sealing the bag. Lots of good technical problems to solve.
There is an assumption in the above that I haven’t justified yet. That the first thing that will have to be done in space by anybody intending to use or return resources to earth surface is to build a manufacturing capability. The justification is straight forward. It costs TOO much to launch a vehicle from earth surface to pick up mass materials in space. Every flight surface, engine, parachute, gear, etc. of the earth surface delivery vehicle will have to be manufactured in space. That is why it has always been considered not cost effective to actually return products to earth surface. However if you have a goal of creating a space manufacturing capability then returning mass materials to earth surface is just part of the justification.