We’ve gone around and around on this question in GD, and it looks like the discussion is beginning to evolve in that direction. But here’s one practical viewpoint out of many dozen possibilities.
It is inevitable that humanity will eventually spread spaceward. We are hardwired to seek frontiers and expand our borders, and by this point we’ve pretty much run out of good places on Earth for habitation; the sparsely populated areas, for the most part, are in deserts or mountains or other undesirable terrain. So it’s no wonder we’re starting to look outwards.
That’s the psychological aspect. The practical aspect: There is a huge amount of money to be made in space, in the long run. For example, one typical metal-based asteroid, containing varying amounts of nickel, iron, platinum, and so on, would have a market value at current prices of approximately thirty trillion dollars. Anyone possessing the wherewithal to create a hundred-billion-dollar program for asteroid retrieval would see a three-thousand-to-one return on even that enormous investment, twenty years down the line— and that’s for just one of them; succeeding retrievals permit amortization of the initial investment, and a huge increase in profitability overall. Plus, that’s a typical asteroid; some are smaller, and some are far larger. (Naturally, there are economic consequences when the supply of a rare commodity suddenly increases, so a large-scale space-mining operation wouldn’t continue to be so outrageously profitable when the rocks are dropping in on a regular basis. But as with anything, the longer it goes, the more we know, and the easier and cheaper it gets.)
Now, to bring it back to Mars: If you’re going to get into space-based mining and manufacturing in a big way, it makes a lot more sense to base it off the red planet than here on Earth. In general, you want to put your refining and manufacturing operation on a planetary body, because zero-G creates a large set of problems; and when considering planets, Mars offers several advantages over Earth. First, it’s closer to the asteroid belt (though there are a large number of bodies between Earth and Mars, called NEOs, that can be retrieved first, before proximity to the belt becomes an issue). Second, Mars has virtually no atmosphere, and significantly lower gravity, which means it’s a lot easier and cheaper to land and take off. Third, as far as we know, there’s no life, so there’s no environmental impact to putting a major manufacturing station in the middle of Tharsis, instead of Kentucky or Ukraine or wherever. Fourth, the similar advantages offered by the Moon as a base of operation are countered by the fact that Mars has ample water reserves, compared to the limited stores of cratered ice on the Moon, thus making a self-sustaining human presence far easier to engineer.
All of that is at least a hundred years in the future, or probably more. That by itself is a downside, because humans are notoriously poor at planning for things they won’t see in their own lifetimes. It’ll need to progress by small stages, probably beginning with the first retrieval of at least one NEO by some deep-pocketed visionary.
But it does, eventually, need to happen. At some point, we’ll need to roll up our sleeves and get to work. In a previous thread on the topic, I offered a story for comparison, about the traffic mess my hometown, Seattle, is currently in. We’ve known there was going to be trouble for thirty years, but we couldn’t agree on a solution, and so we did nothing. For a while, it was easy to keep dickering and debating, because the pain hadn’t really started, and the benefit of any program was twenty years in the future. Thirty years later, if we’d actually started something, it would have been done ten years ago. We didn’t, and the solution is still twenty years away, but now it’s even more expensive and politically contentious, because the players have become entrenched. We all know something has to be done, and we all know it won’t show results for twenty years, and so we continue sitting on our hands while the problem gets worse and worse. Just human nature.
We have the capability to make some initial moves in the direction of long-term growth into space, tentative and limited as they might be, and we’re doing some of them now. But we need to pick up the pace, because we need to make mistakes from which we can learn. We need to have a basis of understanding upon which plans can be built. Eventually, we’ll need to put people on Mars just so we can learn how to do it, in order to make the eventual uses practical instead of theoretical.
Right now, there is no concrete return-on-investment reason to be doing any of the things we’re doing in space (with the sole exception of communications satellites). In the long run, though, even the sky will be no limit. Whenever we start working on the problem in earnest, it’ll be a hundred years before we see something resembling a mature industry in space, a network of privately-held profit-based operations that drive humanity’s interest into the new frontier. If we get going now, it’ll be a hundred years from today. If we wait twenty years, it’ll still be a hundred years from then. There may be future technologies (nuclear thermal rockets, for example, or advanced polymers that make spacecraft easier to build) that cut off a few years from this time frame, but mostly it’s about getting the actual real-world experience, making mistakes and solving problems day after day after month after year. And that, simply stated, takes time.
So as far as I’m concerned, we might as well get started.
