Two researchers from the University of Central Florida – Kevin Cannon and Daniel Britt – have been looking at how a Martian colony might feed itself. Although NASA has been growing some food on the International Space Station, its goal is to supplement the vitamins and minerals in a standard astronaut diet and to improve crew morale – it’s not about making a space station, or a colony, self-sufficient.
But SpaceX has a different goal, which is being the transport infrastructure for a Martian colony that grows to a million people or more. Feeding that many people, so far from Earth, becomes a different challenge. To avoid shipping in vast quantities of food – at enormous expense – the only solution is to make agriculture possible on Mars.
Cannon and Britt have made several assumptions of the kinds of agriculture that might thrive on Mars, assuming a commercial, market-led system similar to Earth. They believe that a Martian colony could achieve self-sufficiency within 100 years. The timescale over which that happens would be primarily determined by how quickly pressurised infrastructure could be put in place, probably in underground tunnels.
Self-sufficiency would require the colony to make as much use of local resources as possible. The settlement will need water, energy, oxygen, construction materials and food. The first four of those are relatively easy with current technology. Solar panels and nuclear reactors will provide energy, we believe there’s extractable water on Mars below the planet’s surface, and the Martian regolith (the rocky surface) can be transformed into building materials.
Food is trickier, as there’s no native plants or animals on Mars, and the conditions on the surface are incredibly hazardous. So what would Martians eat?
To begin with, the colonists are likely to rely on plants grown in hydroponic systems under LED lights. However, these rely on inputs from Earth, from plastic trays and hoses to nutrients and growing media. It will be more efficient to turn Martian regolith into soil, but at present we don’t know how to do that. We don’t have soil samples from Mars yet, and so scientists are running experiments on simulated Mars soil. Further research will be needed once we get our hands on some actual regolith.
As they scale up their growing area, the Martians will want to focus on staple crops that give a good yield of calories as well as other nutrients. Good choices include corn (maize), wheat, sweet potatoes, soybeans and peanuts. However, a study carried out on people who endured long missions in Antarctica showed that the foods they missed most included tomatoes, strawberries, cucumbers and bell peppers. A variety of foods will be needed to avoid ‘menu fatigue’ and keep the colonists well-fed and happy.
Considering the US population, research shows that there aren’t many people living on a plant-based diet and that 84% of people who try doing so switch back to eating meat at some point. But we’re not in a position to transport live animals to Mars, and the colonists won’t have the pressurised space needed to raise farm animals. The researchers have concluded, therefore, that Martians will use bioreactors (“cellular agriculture”) to produce artificial meat, fish, eggs and dairy products. Not only is lab-grown meat an efficient use of resources, but it removes the ethical considerations of raising animals for meat. Bioreactors can also produce algae-based foods, including spirulina and nori.
Edible insects are also likely to be a large part of the Martian diet. Farming insects doesn’t require a lot of space and can be automated, and insects can eat plant and food waste. Although Western cultures tend to find the idea of eating insects disgusting, insect-based foods are gaining ground, and the global market could be worth more than a billion dollars by 2023. The researchers note that most people find the idea of incorporating a processed flour made from house crickets (Acheta domesticus) into recipes and food products more acceptable than whole insects.
Martian agriculture will have to be an integral part of the wider support system, with plants and cyanobacteria also producing oxygen and removing carbon dioxide from the atmosphere. Martians will need to recycle food waste through insects and earthworms and transform human waste into fertiliser.
The researchers conclude that:
“Lessons from sustainable practices on the Earth should be adapted for a martian settlement and, in turn, spinoffs from developing the technology to get humans to Mars can be used to improve sustainability and reduce greenhouse gas emissions on the Earth.”
As culture meat and edible insects become more widely available, it will become easier for us to switch to a “Martian” diet, and the researchers have created a website – EatLikeAMartian.org – offering some on ideas of adopting “sustainable Mars-like eating habits on the Earth”.
Kevin M. Cannon and Daniel T. Britt. Feeding One Million People on Mars. New Space. August 2019.
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