> What would our houses and cars look like if there was a limitless supply of aluminum?
There IS a limitless supply of aluminum. The top kilometer of crust all over the earth is stunningly rich in aluminum. It's just that PROCESSING it takes energy.
...just like processing an asteroid.
Dirt, though, has the added advantage of already being HERE.
There's "plenty" of titanium here too, most of its just in the form of titanium dioxide which happens to be very hard to turn back into the good stuff. (But its fantastic for making paint..)
As I recall, the allure with metals in asteroids that they are "hunks of cut up planets". Instead of digging and processing, you just scrape the good stuff off the surface and (being in deep space and all) its not oxidized or otherwise contaminated like it is when found on earth. You build your kickass starship out of it right then and there or encapsulate it in some heat shielding and drop it in the nearest ocean for retrieval.
A great many people who bought a bunch of gold as a hedge against inflation might be disappointed though...
I suspect the metals are oxidized on the asteroids, too. If aluminum takes so much energy to liberate from the oxygen, it must really like to combine with oxygen. I'd guess there was a fair amount of oxygen floating around with the aluminum before it clumped together into asteroids, even if there isn't now.
Asteroidal resources are unique and diverse. In general, they are different from the dirt beneath our feet and the ores that we mine from our planet's crust. Likewise, they are much different than the Moon, Mars, and other planets' crusts. Asteroids are much more metal-rich, like the core of the Earth, Moon, Mars and any other planet, and unlike their crusts. The asteroids are normally not as enriched in oxides, silicates, and the other lighterweight elements that floated up to dominate a planetary crust. Many asteroids are like a mixture of a planetary metal core plus a crust plus the mantle in between. Some are entirely like a core or a mantle or a crust, having come from a large parent body which was broken up. In most asteroids, free metal is abundant in the mix, and often dominant. This free metal can be used without any further industrial processing.
I don't have a good explanation why (lack of pressure, maybe?) but this doesn't seem to be the case. For example, I've seen the 60-ton Hoba meteorite in Namibia, and although the surface has corroded and oxidised, its bulk is definitely solid metal (mostly iron, some nickel).
It would still take some processing to separate the compounds, but nowhere near as much as ores.
Which is exactly why we need fusion power and not the hydro, wind and solar power the shortsighted environmentalists keep pushing. Those will never produce the vast additional amounts of energy needed to make the next step in our general wellbeing. With cheap limitless energy, you can produce all the water you want, bind all the CO2 you want, produce all the O3 you want, recycle everything you want and even use fission to produce whatever materials you want.
And what makes you think fusion will actually turn out to be that cheap? People said the same thing about fission, but it's turned out to be quite expensive, and the technology is likely to be very complex. If you calculate how large area of photovoltaics you can build for the price of developing and building a fusion reactor (not that anyone has any idea what this cost will be), I suspect you'd get a lot of it.
And what makes you think fusion will actually turn out to be that cheap?
Because fusion scales well. With time, everything limited by technology becomes cheap as technology advances. There are no fundamental problems or limits in fusion, just practical problems. Fusion has never received the amount of funding it should have received. How long did it take ITER to get the measly 10 billion dollars required?
As for fission: the all important difference is that the fuel for fusion is much easier to get, is unlimited and the garbage that gets left behind isn't nearly as much of a problem. Moreover, there is no risk of blowing up half the nearby city and irradiating the area for the next 100K years. Fusion and fission are incomparable as for their ability to provide energy.
Solar power is you sitting 200 feet away from a bonfire. Fusion reactor power is placing a space heater directly in front of you. If you were cold, which would you prefer?
A mirror is orders of magnitude cheaper than any fusion containment system you care to name, also orders of magnitude less mass.
Seriously, do the math, for the applications we're talking about (asteroid mining), given that the solar constant at earths orbit is roughly 1400 Watts/m^2 a relatively modest set of mirrors could be used to heat metal up to working temperature.
There IS a limitless supply of aluminum. The top kilometer of crust all over the earth is stunningly rich in aluminum. It's just that PROCESSING it takes energy.
...just like processing an asteroid.
Dirt, though, has the added advantage of already being HERE.