And yet NASA was perfectly willing to shell out a billion to launch the Ares 1 while SpaceX was able to launch a rocket with the same amount of payload capacity for $50 million. NASA routinely goes over budget on nearly everything precisely because they are fundementally inefficient, with a bloated bureaucracy and highly protected jobs. One of the biggest reasons the shuttle lasted as long as it did was because it was viewed more as a pork barrel earmark rather than an asset, each shuttle took several thousand people for each orbiter just to keep it airworthy (for comparison the Skylon is intended to have a support crew of just 200).
Which pretty much means we agree on this point. Private sector hates negative profit more than governments and will be more efficient by definition.
Ah but mines crank out continual streams of said expensive ores. Once the machinary is up there it stays there, forever. Once the rock you're currently mining is depleted, you move it to another one. The machinery is a one time investment and people get rotated and resupplied on each trip. But you're also forgetting something important, what happens to the other metals? They stay in space where they will be used to build the infrastructure in space needed for future expansion. That greatly reduces the cost of space construction allowing for great expansion beyond the initial infrastructure you claim wont happen for centuries.
Machines a one time investment? Mining machines? You're kidding, right? I actually work for a company that, among other things, produces machines used in deep mining. The strains put on these rigs are enormous and even with the best quality control you have a constant need for maintenance. When you drill something, zero g or not, you will produce three things in excess; friction, heat, and fine dust. None of these play nice with your machines. Your drills will slowly dull no matter what super material they're from. Fine dust will catch onto your machine's parts no matter how well you protect them. Heat will do it's thing making sure the degradation is faster. You will have to isolate your constantly drained batteries well and replace them every now and then. And I haven't even gone in the technical challenges of near zero-g gravity environment mining, unknown (so far) tectonic stability of these rocks (you know, a part of a rock breaking off and floating away with your drill attached to it isn't nice) or the fact you have no Earth's magnetosphere protecting your equipment's electronics from solar winds and enormous amounts of radiation our Sun churns out. Mining machines mean a constant amount of maintenance even on Earth. In space, the needs and costs of that maintenance would rise exponentially. And we had real technical challenges just fixing the Hubble for the last time which is right here above us, not in some asteroid field over 2 AU away that took our latest probe over 5 years to reach. Even if that wasn't the case the costs of doing this would be astronomical if run from Earth. With the constant need for maintenance we're talking about sending manned missions for doing this, sending new machines to replace old ones each time they break, or having some sort of automated repair droids that would cost another infinite amount of money, r&d of tech we really don't have yet, and introduce even more parts to maintain in an already convoluted equation.
Or you can go mine your aluminum on Earth and have it shipped over on trucks/ships at a fraction of the cost.
What you're proposing would only make sense if we already had an extensive presence at least in the inner solar system. Otherwise, I don't think you realize just what sort of technical difficulties and engineering challenges you'd run into.
The process would need to work like this;
- cost effective, large scale way of getting to the orbit and beyond developed (don't have it);
- Mankind starts setting up in space. Research outposts crop up on the moon and Mars, following by larger and larger settlements appearing around them.
- We build orbital shipyards to facilitate interplanetary - only travel as we go further and further.
- To support these, we build mines on asteroids and low gravity planetoids as a cheaper way of getting resources that essentially stay in space while mined.
And not like this:
- I want us to be in space so orbital mines, now. We had some rejected space propulsion concepts in the 70's and 80's so surely that means we're technically able to it. In fact let's just use nuclear pulse propulsion or nuclear rockets and launch right from LEO. Getting a bunch of hydrogen bombs detonated over people's heads every time we need to go mine some rock will get approved like a snap.
- Let's find a way to use these mines now! It has to be cost effective, right? It's space, it's cool, I want it now.
Don't get me wrong I want it now too. Fact of the matter is if it was actually cost effective we'd be out there now. And sadly neither one of us will be skiing on Mars for vacations. I don't like it any better than you do but you can't blame the politicians for that. You can blame them for not investing enough in science, new propulsion technologies and space exploration. You can blame them for cutting NASA's budget yet again. You can blame them for canning the shuttle while having no replacement in sight. You can blame them from essentially giving up on putting boots on Martian ground, meaning rather low chances of seeing man on Mars during our lifetimes.
You can't blame them for not having colonized the inner solar system and not setting mines on asteroids. A lot of things need to happen before we get there. Problem is, we're not doing them. As for the private sector, when they smell money in a more serious space presence, with the technical means to make it profitable, don't worry it'll happen. The fact it hasn't so far speaks for itself.