A few stray thoughts on Martian colonisation and its funding.
1) Frame of Mind
How many people would actively consider joining a colonisation program and emigrating to Mars?
One clue is Antarctica, the closest terrestrial analogue to conditions on Mars. Even if there was a group out there actively promoting the idea I wonder how many people (especially those from the more comfortably well-off areas of Earth--the very demographic who seem to be most in favour of going to Mars) would pay money--especially large amounts of money--to go live in Antarctica permanently? They might stay there for a week in a 4-star hotel. The more adventurous might even "rough" it on an Antarctic trek or to do a season or two of field work as part of a Mars (Ant)arctic research station expedition from the Mars Society. But go live there, permanently, in the modern-day equivalent of a log cabin, with no maid or child care, no running water, no nightclubs, no MTV--and (probably) no prospect of necessarily turning a profit in one's new location without long years of work, and manual labour-type work at that?
Without doubt a few would. But I also seriously doubt whether you would see large numbers of 21st century Westerners making the journey; and all the more so if they had to pay their own fares (as was usually the case with 19th century emigration from Britain to the US). Most of the huddled masses of the US and Europe seem quite comfortable where they are at the moment.
That is, it is not enough for countries or companies to be competing with one another to send colonists to Mars if they have no reservoir of would-be colonists to send. As a general rule the well-off are unlikely to emigrate to untamed wildernesses, be it Antarctica, Mars, or the American frontier of the 17th, 18th, and 19th centuries. Those who do more usually consist of those people who for one reason or another--eg poverty, war, religious or political persecution, etc--are not satisfied with their existing situation in their existing homelands. By contrast, the United States and other Western countries have largely become a society of the well-offs. Their own frontiers have vanished--these days you can do a tour of America's from the comfort of an air conditioned coach--and all they have left is nostalgia.
I cannot help suspecting that it is that nostalgia--not to mention the romance of the idea--which largely sustains the idea, especially in America, of colonising Mars. Quite large numbers probably wouldn't mind exploring Mars, but they would also probably expect to come home again and not be so long away that they would have to give up their jobs back on Earth. Far fewer would probably want to go live there permanently, leaving behind--probably forever--parents, siblings, colleagues, homes, jobs, and country.
The problem then becomes one of numbers and affordability. If the people most inclined to go cannot afford to go, while those who can afford it don't want to go, then will the number of those who do
want to go and can
afford to go be enough to sustain a program of emigration, especially in the longer term?
2) Living off the Land
Then there is the cost of martian colonisation. And I do not mean the cost of getting there.
Colonising the Red Planet is not going to be just a matter of sending out a shipload of would-be emigrants, having them land at some suitable spot, and setting up a settlement--which for all practical purposes is what (say) the Pilgrim Fathers did at Plymouth Rock and Australia's First Fleet did at Sydney Cove. The Pilgrim Fathers and the First Fleeters could hunt or fish for food & furs, graze their flocks, and farm the land. They could also obtain water from local springs, ponds, or streams to wash in and drink from, and they could cut timber from the local forests to build huts for themselves to live in and for firewood to keep warm with. They could also trade with the local natives.
There are no natives to trade with on Mars, no game for the newcomers to hunt nor fish to catch to provide food or furs, no forests to cut for timber or firewood. Most importantly, the colonists will not be able to plant crops or graze flocks in or on native martian regolith--not without a lot of technological help. If they want to do any farming or grazing each and every little plot of land used for such purposes is going to have to be sealed off from the real martian conditions (behind and beneath some kind of dome or other man-made construction), soil imported, created, or simulated--eg via hydroponics--and oxygen, water, trace nutrients, etc pumped in.
In other words, unless and until terraforming happens nobody is going to be living off the land on Mars. Not in the way the Pilgrims could at Plymouth Rock. Not without a lot of technology behind them. Even the very air they breath is going to have to be either shipped in from Earth or generated out of local materials using some kind of technology.
That inability to live off the martian land without the aid of technology is going to make colonising Mars a hugely expensive undertaking. Every single house and settlement will need to be equipped in ways that the Pilgrim Fathers did not have to do with their log huts at Plymouth Rock.
3) Settlement Patterns and Land Values on Mars
That in turn is going to affect settlement patterns on Mars. If certain critical infrastructure and services are necessary simply to survive on Mars then rather than having a large number of small settlements (with the occasional larger one here and there) that we tend to find on Earth the temptation will be to have a small number of large settlements because the cost of the infrastructure makes it more cost-effective to centralise services like oxygen and water production in a few centres.
More critically there are unlikely to be any farms as we know them on Mars. Instead (assuming agriculture and grazing as we know it does go on there) the cost of providing Earth-like conditions to grow crops etc is likely to induce farming and grazing of a highly centralised and highly intensive kind.
It is the scattering of farmholdings across America, Europe, Australia, and elsewhere which produces the settlement patterns we see in those places. Each hamlet or town in a rural area services an area of farmland. In addition, if there are no farms on Mars because the cost involved means that food production must be centralised then the implications go beyond settlement patterns. It will potentially impact on the value of land.
Most land on Earth--not counting wastelands such as deserts and ice caps--is used for agriculture or grazing. However, if most martian land cannot be used for those purposes--indeed, not even just to live on because the owners would be too far from the places with have the infrastructure which provide essential services such as oxygen production--then for all practical purposes most land on Mars is probably going to be effectively worthless. In fact if the recipients then had to pay land taxes on it the government could probably not even give it away!
That in turn is going to impact on any colonisation program. One of the inducements that drew emigrants to places like the US, British North America, and the Australian colonies in the 19th century was the chance to own their own plot of land. Large numbers of immigrants were farmers. It was the growing numbers of those farmers, and thus the need to provide land for them, which pushed the American frontier ever westward. It was a similar situation in Australia, but with a twist worth mentioning. In Australia the colonial governments (initially at any rate) had problems inducing British emigrants to come out. It was far cheaper (and not as far) to sail across the Atlantic. In the end what the Australians did was establish their own subsided immigration programs, with the subsidies paid for by the sale of land in the colony.
One of the ways martian colonisation might also be funded is by the sale of land on Mars. However, if the people who go to Mars cannot live on the land they own because that land cannot support them without expensive infrastructure they cannot afford and no one else will pay for, then you remove one of--if not the--major reason most people would have to buy land on Mars. The only land most people would probably pay for there would be land in or near one of the settlements, because that would be land they would be able to use.