Iron asteroids or meteorites are 91% iron (thus the name), 8.5% nickel and .6% cobalt. One large meteorite could produce a great deal of iron for manufacturing buildings. For example the 3554 Amun asteroid is a mile wide and by itself could give us more iron than mankind has processed in all its history!
Stony asteroids and meteorites typically contain 36% oxygen, 26% iron, 18% silicon, 14% magnesium as well as smaller amounts of aluminum, nickel and calcium. With the proper refining technology a stony meteorite could produce plenty of other building materials (silicon and aluminum are used on Earth in construction projects of all kinds). Earths crust has oxygen, silicon aluminum iron and other minerals, so the processing of an asteroid wouldn’t require totally new technology, just a few refinements to account for gravity and other conditions particular to space mining.
The Moon's surface is a treasure trove of NEO mining possibilities! From the 42% oxygen to 21% silicon to 13% iron, 8%calcium, 7% aluminum 6% magnesium and 3% of other minerals, we could do some serious mining, indeed! Mankind has been mining the Earth for thousands of years and not depleted the supply significantly, so the moon would be in no danger of being “over mined.”
And how about comets? They race through the galaxy, sometimes coming quite close to the Earth. They are made of a combination of ice and space debris. The ice contains water that could be melted and used as water with a little filtering. It could also be broken down into hydrogen and oxygen, which are two main ingredients for rocket fuel. It is possible to capture a comet, mine it for its water and refuel a space ship for lengthy journeys. Not quite as convenient as visiting your local gas station, but a system that could turn comet ice into rocket fuel would improve with use and the technology would advance quickly.
Ships large enough to contain metal refineries and mineral processors would be a combination of terrestrial industry and space technology and are within the realm of possibility by the time a moon base is established. Being able to “capture” asteroids or meteors or comets so they can be mined is theoretically possibly, according to some experts. They expect it to be a common practice sometime in the new century. NASA has charted several NEA’s that either precede or follow Earth’s orbit around the sun and is considering them as the first targets in their mining experiments.
In the old days, people used what was available to build their homes and towns, mostly stone and wood from the immediate area where the building was to take place. In the space age, we can do the same thing by mining the comets, asteroids and meteors that are close enough to reach. The building materials and supplies are already there, just waiting for us to come after them. In the coming century it will be a commonplace thing to get water and fuel from comets, as well as to create habitable bases on the moon and Mars by using their own natural resources and our technology.
