A while back, we reported on a research group that was using an interesting mix of materials to create concrete on Mars. The University of Manchester researchers used blood and urine to create concrete bricks using Martian regolith stronger than concrete used on Earth. However, there was an obvious downside of literally requiring blood to make them, let alone the side effects of having astronauts potentially live in a building built partially out of their own bodily fluids. So the researchers thought up a different material whose usefulness in space will be familiar to anyone who has read Andy Weir’s most famous novel – potatoes.
Potatoes bring a lot of benefits to space exploration. Most importantly, they’re an extremely efficient and stable source of calories. But their starch can also be used as a binder when making concrete. Specifically, it can bind together materials, such as Martian or Lunar regolith, to create something akin to what we would typically consider concrete.
The resultant material, known as “StarCrete,” is twice as strong as typical concrete used here on Earth, at least from a compressive strength perspective. When the potato starch is mixed with lunar regolith, the resultant material is even stronger, clocking in at almost three times the compressive strength of concrete typically used on Earth.
UT video examining the extend of ISRU on Mars.
Another disadvantage of typical concrete is its environmental record – concrete production is responsible for 8% of all CO2 emissions, as it requires extremely high temperatures, typically up to 1300 C, to create. Starcrete can be made at temperatures closer to a typical home oven of around 190 C. So there is an environmentally friendly use case for using Starcrete to replace typically made Earth concrete back here on the ground.
To this end, the researchers at the University of Manchester have created a start-up company called DeakinBio which is seeking out potential use cases for StarCrete on Earth. They’re certainly not the only start-up seeking ways to decrease the CO2 emissions of the concrete industry. And it certainly won’t be as easy to get the raw ingredients of their material on Earth as it would be on Mars or the Moon. But it’s certainly worth a shot.
If the start-up route happens to fail, though, there could be a silver lining. It seems difficult for the researchers to move away from utilizing bodily fluids to construct their materials. To be honest, there’s a good reason for that – people can be viewed simply as bioreactors that can create blood, urine, and in some cases, tears, so there will always be a steady supply of those on any long-term space mission.
Another UT video looks at the technology discussed in this article.
Ironically, despite moving away from the first two bodily fluids, the University of Manchester researchers found a use case for the third. Magnesium chloride, which admittedly is also commonly found on the Martian surface (but not on the Moon), can dramatically improve the strength of their StarCrete. Chalk another point up for material scientists’ ingenuity (and strong stomachs).