Talk-Polywell.org

Anyone interested to collaborate with me on some details of a solar space smelter, please do shoot me a private note. The challenges here are many but the rewards could be impressive.

The intention is to design a solar smelter that can be used out at the asteroid belt and therefore reduce the transport costs of materials found there such that only refined materials are being shipped through serious delta V. The design intention is a balloon structure:

http://www.solaripedia.com/13/130/solar ... power.html

and this certainly creates numerous challenges, especially deposition of unwanted materials inside the balloon, which would destroy its utility. There are some novel ways around this. Likewise the ability to focus sunlight very specifically on various portions of an asteroid in exclusion to others, poses an engineering challenge, but one that may have happy consequences. Additionally, smelting in microgravity has significant challenges attached that need to be addressed such that one has a commercial application. Finally there is the challenge of claiming carbon so it can be turned into thread. Waste not, want not.

If you're an engineer, and interested to look at the issues in hopes of developing first a hobby, and later perhaps a serious business model, shoot me a note and we'll see if we can't get a small working group off the ground.

Interested to scoop Planetary Resources, or even sell them a process? Write me.

Solar flux at the asteroid belt is much less than here, so you'd be better off designing a non-imaging solar concentrator. Non-imaging optics are theoretically able to get 4 times the concentration compared to an equal-aperture imaging collector such as a paraboloid, and do not need to be pointed as precisely. The simplest one is just an internally reflective cone frustum, with optimized opening angle. See the work by Winston et al. A "cone" could be done with inflatables as in your link, but it's probably easier to get something like a one-sheet hyperboloid approximation instead of a regular straight-sided cone.

Most smelting processes involve more than just heating ore. If you're looking to cook out water and other volatile chemicals (the primary material Planetary Resources appears to be after) you'll need to heat the ore in an enclosed space where boiled off material may be collected. Some native metals in an asteroid might be extracted by carbonyl process or similar reversible reaction producing a volatile compound, again in an enclosed space.

Many smelting processes used here on Earth involve a chemical reaction between the ore and some other material. Such as oxygen from air roasting sulfides to oxides, or carbon as a reducing agent. For asteroid mining a means to recover these added materials would be very useful.

The only process's I know of for asteroid materials that don't require an enclosed space are magnetic/electric separation and casting of raw material. So efficient and reliable methods of bringing rock into the refinery are essential.

DeltaV wrote:Solar flux at the asteroid belt is much less than here, so you'd be better off designing a non-imaging solar concentrator.

Not really. Lower intensity solar flux will need a larger collector for the same amount of light. Max concentration possible is a function of the temperature of the source, the sun. The source is the same temperature, but a smaller angular size as seen out there, so a given concentrator operating at the diffraction limit might produce a smaller point of the same intensity.

There are lots of smart guys here. This is why I posted as I did. I will own however, that my post does not explain in detail what I'm after, and in fact misleads in some small degree. Obviously, such a thing is necessary for such a project. My apologies for this.

But yeah, there are several issues that I can't explain here. If you want to be involved, write me privately. If you just want to show how clever you are, post away!