Robert Ayres, well known for his work on biophysical economics, gave a talk dedicated to space mining at the School of Physics in Les Houches this March. Ayres just touched the subject that gave the title to his talk, spending most of the time to describe the plight of the mining industry, faced with the shortage of rare minerals. Yet, the fact that he used that title is an indication of the increasing popularity of the meme of mining space. It is still a marginal subject of investigation, but you can see the trend in Scopus, here, for the search term "space mining":
In a previous post of mine, I was not optimistic about space mining. I said that there was nothing interesting to mine in space and that the whole idea was proposed by people who knew little or nothing about geology. Asteroids and other small space bodies contain no ores because they never went through the processes of deposit creation that took place on the Earth. No ores- no mining. Basically, the growth of interest in the subject may be more a symptom of growing desperation rather than something that could be plausibly done.
I remain more or less of this idea: going to space to bring minerals back to Earth makes little sense, But, recently, I have been re-examining the concept and I discovered that there may be a logic in it if we just we change the target market from the Earth to space.
Space is a growing business with plenty of interesting applications: communication, exploration, astronomy, earth monitoring and more. Elon Musk is no fool and if he developed a heavy rocket launcher, it is because he saw the need of it. So far, every gram of the devices and the structures sent to space came from the Earth's crust. And sending things to space is awfully expensive. So, it could make sense to examine the possibility of assembling space structures using materials mined in space.
It would still be difficult, perhaps impossible, to mine rare minerals in space, but asteroids are rich of elements such such as iron, nickel, aluminum, titanium, silicon and even carbon and water in the form of ice. These minerals are not there in the form of ores, but they form a sufficiently large fraction of some asteroids that extracting and purifying them could make sense. Take also into account that space is rich in solar energy that can be transformed into electric power by PV panels and that in space you have little to worry about pollution and greenhouse gases.
Of course, putting together a mining industry in space is a task which was never attempted so far and the unknowns are enormous. It was discussed back in the 1970s when the concept of "space colonies" became popular. But, over the years, it became clear that humans are not made for space; too expensive and too dangerous. Instead, space is a good place for robots which can do the same things human can do in a better and cheaper way. And these robots could be made, at least in part, from materials obtained from asteroids.
Is it possible? It depends on the trajectory of the world's economic system. If we manage to collapse as badly as some models predict, then space robots will soon become something made of the stuff dreams are made of - just like the angels which once were thought to be pushing planets along their orbits. But if humankind manages to keep a functioning industrial economy, then why not? Our robot-children could explore space and maybe build a new silicon based ecosystem, out there. The future is beautiful because it is always full of possibilities.
