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When humans manage to land on Mars, there is question of how many people would be needed to keep everyone alive. Gwynne Shotwell is the president and CEO of SpaceX. Last year, she speculated that humans may land on Mars by 2040. If this is true, then it is time to consider the feasibility of a Mars colony and how many people would need to be there to keep a colony functioning.
The technology required to make Mars habitable remains an ongoing project. Some researchers have already used mathematics to explore an answer to the question of the minimum number of colonists needed. A paper published in Nature in 2020 by Jean-Marc Salotti concluded that one hundred and ten humans would be required to create a self-sustaining colony on Mars. Salotti is a professor of computer science at Ecole Nationale Superieure de Cognitique, Institut Polytechnique de Bordeaux in France.
There have been other attempts to estimate the minimal number needed to sustain a Martian colony. A study conducted in 2003 put the low-end colony at one hundred. Another paper published in 2001 suggested that a self-sustaining colony could be established on the North Polar Cap of Mars with five hundred people. That may be more people than are really necessary. A group of researchers from George Mason University in Fairfax, Virginia, has decided that a Mars colony could get by with just twenty-two colonists.
The group of scientists included Edgar Arguello, Sam Carter, Cristina Grieg, Michael Hammer, Chris Prather, Clark Petri, and Anamaria Berea. Their findings were described in a pre-print paper titled “An Exploration of Mars Colonization with Agent-Based Modeling.”
Anamaria Berea is an associate professor of computational and data sciences at George Mason University and one of the co-authors of the research. She said, “We started our study after we saw [Salotti's] paper and we wanted to verify that number.”
Berea said that the Nature article made many assumptions that did not take into account the reality of social and psychological behavior and the continuity of human interactions. Berea said, “We tend to often treat humans as just numbers or particles devoid of personal incentives, heterogeneity and adaptability. Human groups are complex systems where the outcome is not the sum of its parts, but synergistic. Any social system exhibits properties of adaptability, emergence, and non-linear dynamics.”
She went on to say, "Additionally, what we included in our model – and it was not included in the other paper – is the relationship between Earth and the habitat on Mars. It is hard to imagine a habitat that will be completely cut off from Earth supplies and independent from the get-go, especially in an environment that is so unsustainable for human life as Mars, even if we would have the best technology to help us there. “The scenario where you can simply send X number of people somewhere and just let them survive is very unlikely, also because it actually costs much more to send tens and hundreds of people into space than sending resupply shuttles.”
In an email sent to a newspaper, Salotti wrote, “Twenty-two is in fact compatible with my 110 as different problems are addressed. Twenty-two is acceptable when shipments from Earth are possible for resupply. It might even be lower. The problem with this kind of approach is that the results highly depend on the set of parameters, which are arbitrary.”
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