Also, any resources in space would have to be very precious to be worth bringing back to Earth. Once we are in a position to start mining asteroids, though, we’ll also be in a position to shape and use those metals in space — which makes better economic sense.

Regardless, I would not support putting the asteroid in Earth orbit. Hemo_jr writes, “It is pretty close to impossible to make a mistake that would send a mile wide asteroid crashing into Earth.” My response to that is three words: Mars Climate Orbiter.

(Google in your friend.)

And it is unlikely that anyone would be moving mile wide asteroids into Earth orbit in the first place – at least for a long while. More likely it will be smaller asteroids — ones the size that would tend to burn up in the atmosphere and not cause a crater – say less than 100 feet/30 meters wide. Those are easier to handle and would give us experience.

As for it being ill-defined. So? There is plenty of time for developing and refining procedures. And mining/extraction is one of the things that could be tested once a small asteroid is captured. There is the energy, in the form of solar power, Mirrors can concentrate heat. Smelting can be adapted to micro-gravity and vacuum. The fact is that industrialization of space will mean less pollution Earth.

When railroads started up in the 19th century, objections were raised based on fears that going 30 or 40 mph was not something that people normally do. And who knows what kinds of physiological problems might be caused by going so fast? Further, people might fall off, they might die.

The objections against asteroid mining is reminiscent of this kind of Luddite reaction. We should be more rational than that.

Furthermore, even limited by the speed of light, some nearby systems may be feasible for colonization, but you’d need the shielding of an asteroid to survive the years in space and not get cancer from the radiation. No need to work this out now, but if a suitable planet is located, then the mass of an asteroid could be used to build the needed shielding as well as provide the “fuel” for a nuclear rocket.

That’s about six times the GDP of the United States. I didn’t even count the value of the iron.

Now, how to get it “down”? Well, say you get it into earth orbit. You could send a shuttle equivalent up to LEO and a manned satellite-like craft to MEO or even higher. Send another with some cutting tools. Chop off chunks — say a ton or so apiece. Attach parachute or heat shield. (Or both). Drop them in. A small reaction control thruster cold fine-tune it as it falls in. To put it in perspective, an asteroid that is coming in at 1,000 miles an hour (twice the speed of a jumbo jet) has a relative speed to the Earth’s surface of zero if it’s coming in prograde.

This is way oversimplified of course. The complicated part, tho, is not, IMO getting smaller bits in to Earth. It’s getting peopel up there to cut it down to size (or robots, but they are really bad at that kind of inexact stuff that requires on the fly thinking — there is a reason we still use people to mine, and it isn’t the expense of robots, necessarily).

I haven’t even gotten to the value of being able to send heavy metals to a space station — easier than bringing it up out of a gravity well.

Collect a number of these objects, composed primarily of water, into Earth orbit. Use nuclear devices – reactors, not bombs – to melt the ice, ending in an ice layer formed by gravitation around a solid – preferably metal – core.

You now have many of the components of a space habitat in Earth orbit without needing to lift them into orbit from Earth.

Energy: the left-over nuclear devices. Water: melt the ice. Oxygen: electrolysis of the water. Shelter: melt the ice and line with plastic foam. Radiation shielding: the object itself. Structural materials: iron from the core.

Add propulsion, hydroponics, etc… you eventually arrive at a long duration space vehicle.

Not saying it’s a bad idea, but I get the feeling the whole proposition is a bit ill-defined.

Sure sounds like a hoot. Let’s do it!