Scientists calculate minimum number of astronauts needed to build and maintain Mars colony

Only about two dozen astronauts are enough to build and maintain a Mars colony, according to a new study, which suggests this low number – compared to previous estimates of about 100 people – can sustain a habitat on the Red Planet.

Researchers, including those from George Mason University in the US, reviewed previous studies, which calculated that anywhere from 100 to 500 astronauts may be needed for a self-sustaining Mars colony based on a number of factors.

Their new yet-to-be peer-reviewed analysis, posted a preprint in arXiv, then additionally took into account human social and psychological behaviour, as well as continuity of interactions between people to make a new estimate.

The findings suggest just 22 people may be enough to build and sustain a space colony on Mars.

Decades of exploration of the Red Planet by space agencies across the world have found conclusively that building any human settlement on Mars is going to be an incredibly complex engineering problem.

The Red Planet’s inhospitable nature also requires any habitat built there to be largely self-sustaining, scientists say.

Apart from mining a few basic minerals and water, future Mars settlers will be dependent on Earth resupply as well as in-situ replenishment of necessities using advanced technology such as splitting Martian water into oxygen for breathing and hydrogen for fuel.

The future colonists will also have to endure psychological and human behavior challenges, researchers say.

In the new study, data scientists sought to better understand the behavioral and psychological interactions of future Martian colonists.

“We seek to identify areas of consideration for planning a colony as well as propose a minimum initial population size required to create a stable colony,” they wrote in the study.

For the analysis, scientists analysed previous data on high performing teams working in isolated and high stress environments such as submarines, Arctic exploration, and the international space station to model the kinds of interactions taking place between agents with four different psychological profiles.

They used a type of computer simulation called Agent-Based Modeling (ABM) that is used to analyse complex systems and predict the emergence of larger patterns and phenomena with simple rules and behaviors.

Using the model, researchers simulated survival of a human habitat on Mars under different working conditions, including when global events such as accidents or delays in Earth resupply, affect the colony.

Scientists created models for Martian settlers with varying individual levels of factors such as metabolism, resilience, skills and their levels, and stress, as well as taking into account one of four psychological traits – neurotic, reactive, social, or agreeable.

The simulation also took into account the environmental variables that the settlers would encounter, the study noted.

As the modelled Mars colonists sleep, move, interact with each other and produce or consume resources, they could also lose health and may die and get removed from the simulation without enough resources.

Five runs of the model for a period lasting 28 years with the initial population sizes in the simulation ranging from 10 to 170 found that “an initial population of 22 was the minimum required to maintain a viable colony size over the long run.”

Researchers also found that the “agreeable” personality type, associated with overall greater empathy, was the one more likely to survive while those with the “neurotic” psychology died at a much higher rate.