[PreciousLiberty]

"And don’t tell me about private enterprise.

They like a return on their investment."

You sir, and I say this with all possible respect, are a shortsighted fool.

I guess you missed this part:

Earth-based mining companies may soon face stiff competition from the mining of gold, silver, platinum and rare earths on asteroids and even other planets.

http://fortune.com/2015/07/20/asteroid-precious-metals/

From that article:

The space rock, which is roughly half a kilometer long, might contain anywhere between $300 billion to more than $5 trillion in precious metals

That is aside from the fact that many candidate asteroids contain more iron than mined in human history. That iron is also already outside Earth's gravity well, which vastly increases its value.

We are on the verge of having essentially unlimited energy at our disposal, and we have plenty now to get started. Once space exploration/exploitation really takes off, the sky is literally the limit.

[G Larry]

LOL!

I spent 45 years in aerospace.

You have no idea of the cost and complexity of asteroid mining, especially if it were to be conducted from a moon base, which is also prohibitively expensive.

And, if you think for a moment, that these would be manned operations, you sir have assigned your own state of reason.

[mrsmith]

Exploiting those asteroids will take propellent.
LOX and ethanol make an excellent propellent and can be produced by a simple farm.
(And you can’t have too much ethanol!)

Assuming $10k a pound, it won’t take much demand to justify producing it on the Moon.

[Svartalfiar]

Once space exploration/exploitation really takes off, the sky is literally the limit.

Um, not really. Once space exploration begins, the sky is no longer the limit!