Future buildings on the moon and Mars may be built from potato starch. A team at the University of Manchester has come up with a building material, twice as strong as concrete, that can be made in a microwave with a little extra-terrestrial dust, potato starch, and a pinch of salt—or in lieu of that, astronauts' tears. It's not feasible to construct buildings in space with bricks carried from Earth at a cost of $2 million each, per AZoBuild. That's why researchers have been developing new building materials that use simple ingredients readily available to astronauts and don't require considerable energy or heavy processing equipment to produce.
The team previously developed a compound, AstroCrete, that used human blood, urine, sweat, and tears as a binding agent, but it wasn't nearly as strong as this cosmic concrete, dubbed StarCrete. "And anyway, astronauts probably don't want to be living in houses made from scabs and urine!" says lead researcher Dr. Aled Roberts. "Since we will be producing starch as food for astronauts, it made sense to look at that as a binding agent rather than human blood." In mixing a simulated Martian soil with potato starch and salt, the researchers created a material with a strength of 72 Megapascals (MPa)—more than twice the strength of ordinary concrete (32 MPa), per Interesting Engineering. Substituting simulated moon dust created an even stronger mixture at 91 MPa.
There's no need for extreme heat or heavy processing equipment, "which all adds cost and complexity to a mission," adds Roberts, whose work is published in Open Engineering. At normal "home baking" temperatures, astronauts can use 55 pounds of potatoes and a little salt—or magnesium chloride, which can be obtained from the Martian surface or astronauts' tears—to create almost half a ton of StarCrete, or 213 bricks of material, according to the team. They've launched a crowdfunding campaign to assist with continuing development of the material—which can also be used as a greener alternative to traditional concrete on Earth—through the start-up DeakinBio. (Read more concrete stories.)