A sustainable, self-sufficient population of one million people can be achieved on Mars within 100 years, according to a new modeling study published by Kevin Cannon and Daniel Britt, both at the University of Central Florida. Their study drew on a plan sketched out by Elon Musk of SpaceX, which begins with about 12 people landing on Mars, followed by multiple ships carrying 100 to 200 passengers at every launch opportunity, roughly every 26 months. The population growth is envisioned to be sustained both by immigration and by births on Mars.
Based on Cannon’s and Britt’s analysis, four of the five major “consumables” necessary for a Martian settlement—energy, water, oxygen, and construction material—can be extracted from the Martian surface in economically practical concentrations. Only food is not obtainable from raw materials on Mars. So, how to solve the food problem? The authors suggest growing plants, insect farming, and cellular agriculture.
Plants have often been suggested in the past, but it would be critical to plant high-calorie crops in order to feed so many people. Insect farming would also be well suited, because it can provide large amounts of calories per unit of land. House crickets are especially suitable for this purpose, and are already used in some granola bars today.
Protein-rich foods also could be obtained from cells grown in bioreactors. Interestingly, clean fish may be favored over cell-grown meats on Mars, because the cultures could be maintained at colder temperatures (closer to 20 degrees Celsius) as compared to the 37 degrees needed for warm-blooded animal cells.
I find these ideas and extrapolations very intriguing. But living on Mars might not be as easy as it seems, even with further progress in technology. Growing plants in Martian soil may be quite a challenge, with perchlorates and other chemicals abundant in sediments found on the Red Planet. In fact, in another study involving the same authors, plants quickly died and earthworms suffocated in a simulated soil similar to the one found on Mars.
Then we have to consider biology. It is far from clear that humans can easily bear children on Mars, considering that Martian gravity is only 38 percent of what we experience on Earth. The human body is adapted to terrestrial conditions, and unexpected complications may result when a basic physical constant is only a third of what we humans are used to. Martian farmers might face other problems, including unfamiliar crop diseases that wipe out their harvests and result in major starvation on Mars.
On the upside, technologies for efficient, sustainable food production on Mars could have benefits for the many more people adapting to climate change back on Earth, and so could prove invaluable for our entire civilization.
Musk’s vision of a million people on Mars is likely not in our immediate future. But it may have gotten more plausible following recent recommendations by a NASA Planetary Protection Independent Review Board, which may lead to lower sterilization requirements for landing in certain regions on Mars where no indigenous life is expected. If people do arrive in passenger ships on Mars and start setting up house, these are the locations we would expect them to settle.