Mars in among the most popular locations in science fiction and since the colonization of the Red Planet is a feasible possibility – at least from a technological perspective – it perfectly well fits in the scope of mundane science fiction. The subsequent question is whether we as MSF authors can devise a credible motive for the colonization of Mars. Basically there are two types of motives for setting up a colony anywhere, economic and ideological reasons.
An example of ideological colonization is that of the migration of religious minorities from Europe to North America to escape prosecution and to establish communities based on their own lifestyle. Besides religious groups also secular groups have sought to found new communities based on what they believed a just society. Such initiatives have varying success, mostly due to lack of sufficient financial means.
History shows that economic gains are a stronger motive for emigration and colonization. It is not without reason that the early colonization of the Americas and Asia by European powers was the work of for-profit businesses – such as the Dutch VOC or the British East-India Company – rather than by direct government action. Even in those colonies which were nominally under state supervision private parties effectively run the colonies.
These colonies primarily served as exporters of goods to European markets. And by exporting goods the colonists sought to make profits and to justify their investments.
Given that travel to Mars is expensive, purely ideologically motivated colonization is pretty much ruled out. And even if we accept that Mars will be colonized for ideological reasons, then we – or rather the colonists – have still to figure out how to fund such project. Therefore colonization of Mars is most likely to be part of a commercial endeavor, unless extremely wealthy idealists would be willing to pay the bill.
Once we assume that the colonization of Mars will most likely be motivated by economic gain, we have to consider what Mars has to offer for potential terrestrial investors. These investor might be willing to bear the costs of this project, provided the return on their investments is high enough. Robert Zubrin has identified two ways in which Mars colonization could be commercially attractive.
First, Zubrin argues that Mars might posses significant amounts of valuable mineral resources, which market value would justify mining and transporting it from Mars to Earth. Secondly, he points out that Mars has a higher concentration of deuterium, a potential fusion fuel and hence a valuable resource for future economy. I have, however, a few critical remarks about these arguments.
Granted that there are very valuable minerals on Mars which could be profitably exported to Earth, it is still the question whether Mars is actually the best location for extra-terrestrial mining activities. First, the escape velocity of Mars is half that of Earth, while the escape velocity of the Moon is just one sixth and that of the near-earth asteroids is just negligible. Further is the delta-V required for travel to and from Mars higher than that to the Moon or large part of the near-earth asteroids. So it might be much less expensive to obtain these mineral resources from the Moon or the near-earth asteroids rather than from Mars.
Only those resources which cannot be found on the Moon or in NEAs but are available on Mars, could possible justify such activities. Tough it remains yet the question whether there is sufficient demand for such resources that colonizing Mars would be an interesting activity.
Zubrin states that the concentration of deuterium is higher on Mars than on Earth. This is true, but does it actually matter? On Earth one out every 6,000 hydrogen atoms is deuterium and in absolute numbers there is more deuterium on Earth than on Mars. That Mars has a higher concentration of deuterium is mostly due to the fact that deuterium is more easily contained by Mars’ weaker gravity than lighter hydrogen atoms.
Yes, it takes less energy to extract deuterium if the concentration is higher, but it is highly questionable whether this gain outweighs the energy required to make a round-trip to Mars. And actually a 1:6000 concentration of deuterium in terrestrial hydrogen does not seem a real problem. Many resources are commercially extracted from even lower concentration and since deuterium is twice as heavy as ordinary hydrogen, separating it from pure hydrogen gas does not seem to be a real issue.
So there is no deuterium shortage on this planet and there are no real problems with obtaining pure deuterium from terrestrial sources, at least not from a technical perspective. Hence this does not seem to be a strong motive for Mars colonization either.
Another idea sometimes suggested in science fiction is to use Mars as a penal colony. The idea is to remove hardened criminal from our planet by sending them away to Mars. But if our goal is just removal, why not just sending them to the Moon instead? There not really that much hardened criminals that we need an entire planet for them. Moon would be large enough and going there is much less expensive than traveling to Mars. Alternatively the death penalty seems to both more humane as much cheaper than sending criminals to Mars, and do we really want to waste our money on criminals?
Sending criminals to the Red Planet might make sense if they were employed as cheap labour in some meaningful activity. But as we have seen above, that won’t be mining – at least not for export, mining would made sense if done for domestic use. Also tourism is unlikely, since a one-way trip to Mars would take six months, while the Moon is just three days away.
A manned mission to Mars is often justified within the context of scientific exploration. However, unmanned missions such as Curiosity have been quite successful and with continuing progress in the field of artificial intelligence unmanned missions would still be first choice for a long time. Yes, manned missions would have some advantages but whether those will outweigh the risks, I dare to question that. Nevertheless a scientific mission is not the same as colonization and what if the result of such a manned mission to Mars, would be that Mars is not a suitable place for human settlement?