From the bottom of our gravity well on the Earth's surface, getting anything into space is difficult and expensive, and that's even more true for travel to Mars.
On the International Space Station, for example, although some air and water is recycled, astronauts are ultimately reliant on Earth for everything. Given the challenges of distance, time, and energy required for the transit, this will have to change for Mars. 3D printing will provide some degree of self-sustenance (especially if we use local building materials where possible), but bulk consumables would have to be transported or generated in situ.
Luckily, Mars has both water in the form of ice, and a thin but useful atmosphere of carbon dioxide that can be processed into oxygen, and methane to power vehicles or rockets.
Being able to produce our own water and oxygen on Mars will be essential to sustaining human life there, but that's only about half the solution (and half the mass). We'd need to send around 2,000 pounds of food per Martian settler per year—and that assumes entirely freeze-dried food, which may not be the healthiest or most palatable option. A Martian settlement of six people would depend on a grocery run of more than fifteen Curiosity Rovers' worth of dry food every 26-month Earth-to-Mars launch window.
Cooking on Mars. Video: Andrew Rader/YouTube
Any food we can grow on Mars is food we don't have to ship from Earth. Since we can get water there, we want to focus any Martian agricultural ventures on high-density bulk calories, high nutrition, or fresh morale-boosting foods that are easy to grow in a small space, while we continue to ship freeze-dried foods and vitamins from Earth.
Livestock is mostly out of the question, except perhaps if the animals are very small. Crickets are one of the best options. They eat discarded plant matter, are easy to raise in small spaces in a matter of weeks, and use hardly any water. They're healthier than beef, with more protein, and include omega-3s, vitamins like iron and magnesium, and less fat.
Other small animals like snails could be on the menu. They may have been one of the first animals cultivated by humans for food. Aquaculture of mussels, crustaceans, and spirulina blue-green algae might round out a Martian diet.
What about plants and fungi? Mushrooms are packed with vitamins and grow without the need for light. As featured in The Martian, potatoes are also a good choice, and they've even been grown in simulated Martian soil in experiments in a greenhouse on Earth. They're packed with vitamins, and contain some protein. You could live on them exclusively for a year or more, although you'd eventually suffer from a lack of fats, vitamins A and D, and B-12.
Cooking on Mars - Potatoes. Video: Andrew Rader/YouTube
Even so, potatoes could contribute the bulk calories to a diet, as they have in many cultures on Earth throughout history. Sprinkle a few crickets on top of your potato pancakes and pop a vitamin pill and you've got a pretty balanced diet.
Or take a page from the 19th century Irish and combine potatoes with milk: in this case, dried milk shipped from Earth, preferably the full fat variety. By a strange quirk, potatoes and milk balance each other remarkably well, each providing the nutrients that the other lacks and forming about the best two-food diet a Martian settler could ask for.
Of course, ideally you're rounding it out with at least a few other foods, if for nothing else than to avoid the monotony of endless cream of potato soup.
A Mars settlement will be dependent on Earth for the foreseeable future, but anything we can do to reduce the supplies we'd have to send brings it that much closer to reality. Changing the way we eat and learning how to grow our own food is going to be a big part of the solution.
Aerospace engineer Andrew Rader is a competitor in the Mars Generation's annual Potato Challenge, held Thursday Nov. 17, to raise awareness and scholarship funding for the future of Science and Space Education. His latest kid's science book, Mars Rover Rescue, is on Kickstarter at www.rover-rescue.com.
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