If we want to have a human presence on Mars, our astronauts are gonna need a place to live, work, and potentially grow their own food. Unfortunately, adding the mass of structural components to a spacecraft’s payload could also add time to the already nine-month-long voyage. Of course, one potential solution to this problem could be exploiting the limited resources provided by the sparse Martian landscape. In a new study, engineers believe they’ve figured out a way to do just that—by harnessing the power of genetically modified yeast.
A team led by engineers from the Hong Kong University of Science and Technology developed a recipe for living, 3D-printed building materials using Martian rocks and regolith, gelatin, and yeast. The team mixed simulated Martian material with yeast genetically engineered to coat themselves in the same sticky proteins mussels use to attach themselves to rocks. They added gelatin from pigs to create a kind of matrix that allows the yeast to grow, while the Martian material provides strength. The result was a living slurry ready to be pushed through a 3D printer.
Read more: “Humans Living on Mars May Not Be Human for Long”
“My inspiration came from freeze-dried fruits that become harder,” study author Jishen Qiu of the Hong Kong University of Science and Technology explained in a statement. “So I asked myself if we can take advantage of that and make some materials.”
Because of the frigid temperatures and lower atmospheric pressure, freeze drying on Mars is considerably easier. So the team tested the living building material in simulated Martian conditions and found that the water froze immediately and then turned to vapor, leaving pores that created a light hardened foam. They created several structures resembling tiny beehives about the size of a wine bottle cork. Tests of their structural integrity revealed they could be scaled up to create human-sized dwellings—with an assist from the red planet’s reduced gravity.
“This is actually strong enough to build a one- or two-story building on Earth whose gravity is three times that of Mars,” Qiu said. “So, you can probably easily build a multistory building on Mars with the material.”
According to the team, this freeze-dried living building material is more workable than proposals that involve heating or melting Martian material because it uses less energy and creates recyclable material. In fact, the yeast themselves could be used by future manned missions. “As long as there’s one yeast that’s still alive, you can grow them again,” Qiu said.
Unfortunately, there’s no information about whether they’re just as good at brewing beer. Then again, Martian homesteaders will probably be too busy for happy hour. 
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Lead Image: Ning Liu
