OK, so humanity is in its infancy in the realm of interstellar space travel.

It took a ton of effort -- and just as imporatantly, a ton of resourses! -- to send humans to the Moon and back, and establish a small space station in Earth's orbit (that holds 10 people max?)

My question is, when we really start to go out and explore the Galaxy (after we develop new methods of propulsion and shielding, etc.), where are we going to get the raw materials from? I'm talking about lots of starships -- and some big ones too! -- lots of starbases (more like floating cities in space than our condomenium space station we have now) -- domed colonies on calm planets and moons without a habitable atmosphere, and actual colonies on Earth-like planets...

I know we can create a system where the air, water, and food recycle themselves. But that's just part of our problem. What about metals? All these starships, starbases, and colonies have to be constructed out of some materials. So do the computers. And anything else we might need along the way.

Where are we going to find that much copper, aluminum, tin, gold, silver, platinum, silicon, carbon, etc.?

(C-type) asteroids are the best choice because they have everything needed to sustain an industrial economy. I claim you cannot harvest just one asteroid. C-type does have hydrated minerals that can be baked at 1,000°C to get water out, and may have ice in the core. Water can be made into LOX/LH2 rocket fuel. However, industrial metals are relatively scarce and in the form of oxide minerals. Those minerals would have to be smelted. However, an iron asteroid is called M-type because it's solid metal. It is composed of iron/nickel alloy and may have mineral inclusions of up to 30%. If the inclusions are more than 30% it's no longer classified as iron, instead it's called stony-iron. Iron can be more than 90%, but on average is 88% of the metal. Nickel is 5%-62% of the metal; the average is 10%. Average cobalt content is 0.5%. We know this from iron meteorites. I treat meteorites as a good sample of near Earth asteroids. Precious metals will also be present. Gold tends to bind to iron, so any iron deposit will have gold mixed with it. Platinum follows nickel. All iron meteorites have measurable quantities of gold, silver, platinum, and all of the other platinum group metals: ruthenium, rhodium, palladium, osmium, and iridium. These 8 precious metals appear to be present in relatively low amounts, but can be easily concentrated to commercially mineable quantities.

Meteorites have a lot of published data, but it's hard to get complete data. One iron meteorite, Allan Hills 84233, has 1070 parts per billion gold; iron and other precious metals are not reported. The bulk average for CI meteorites is 145ppb gold, but much more platinum. If the ratio of gold:platinum holds the same this would provide a great deal of platinum in an iron asteroid. This can be concentrated by simple means: grind the asteroid into iron filings, centrifuge it and use a magnet to collect magnetic particles. This would collect metal and discard the mineral inclusions. Then use the Mond process to extract ferrous metals. This works by pressurizing the ore in pure carbon monoxide and heating to 50°C, nickel with combine to form nickel-carbonyl gas. That gas is drawn off and heating in a second chamber to 230°C which breaks it down, precipitating nickel leaving carbon monoxide. This cycle is used commercially to produce 100% pure nickel. It also works with iron and cobalt, although they have slightly different pressures and temperatures. This produces iron, nickel, cobalt, or iron/nickel alloy with highly controlled proportion. It also leaves behind everything else from the metal. The left-overs will have highly concentrated precious metal.

Typical M-type asteroid, metal portion:
88% iron, 10% nickel, 0.5% cobalt, 1.5% everything else.
Precious metal - ppb - troy ounces per short ton of ore - concentrated ounces/ton
Gold - 1070 - 0.0312 - 2.08
Silver - 1476 - 0.0430 - 2.86
Platinum - 7379 - 0.215 - 14.3
Ruthenium - 5239 - 0.15 - 10
Rhodium - 1033 - 0.0301 - 2.0
Palladium - 4132 - 0.12 - 8.0
Osmium - 3616 - 0.105 - 7.0
Iridium - 3431 - 0.100 - 6.67

Resoures will not be a problem if we can get into space easy and for cheap

That's great news!

It helps that we already have the technology to mine these metals & minerals. Will these mining techniques work in the vacuum of space, in zero gravity, though?

There is an abundance of asteroids in the Solar System we could use if we could get to them... random ones just flying around, the asteroid belt, the rings of Jupiter & Saturn...

Start recylcling now...mine astrdoids for it in the future (later).

Originally posted by ThunderCloud
That's great news!

It helps that we already have the technology to mine these metals & minerals. Will these mining techniques work in the vacuum of space, in zero gravity, though?

There is an abundance of asteroids in the Solar System we could use if we could get to them... random ones just flying around, the asteroid belt, the rings of Jupiter & Saturn...

We would have to adapt our mining technology to work in space but I think there would be no major problems in doing it. Robots in my opinion would be the best bet for these type of mining conditions. The M tpye asteriods or such condensed sources of metals compared to earth mines its amazing how many thousands of tons of rocks earth mines must move to get a couple of ounces of gold.

There was one M type asteriod found I forgot its name but it contained so much metal if it was mined it would be worth more than the entire United states it was like $200 trillion in different metals it was quite amazing.