Imagine a house on Mars. Is it full of bacteria?
When we send humans to MarsThey will need places to live. In a new study, a team of researchers from the Indian Institute of Sciences (IISc), in collaboration with the Indian space agency, the Indian Space Research Organization (ISRO), suggests a new method of using bacteria to build these Martian habitats.
In this method, the team shows how “space bricks” could be made to build a habitat on the Red Planet with a combination of local Martian soil, bacteria, and urea, a waste compound eliminated through urine by mammals.
Related: Newly discovered bacteria on the space station could help astronauts grow plants on Mars
To make these Red Planet “space bricks,” the team mixed a simulated Martian soil “slurry” made from guar gum, which is a product of processed guar beans, combined with urea, the chemical nickel chloride, and the bacteria Sporosarcina pasteurii. This mixture is mixed and can be poured into molds of any shape.
Previously, this team had tried to make “space bricks” with simulated lunar soil, but they were only able to make cylinder-shaped bricks, whereas, with their new Martian method in which they harden a “liquid” mixture in a mold, they could make bricks of any shape, according to a statement.
After a few days in the mold, a chemical reaction transforms the “slurry” into a solid “space brick”. Within the mixture, bacteria and urea interact, causing the urea to crystallize and form calcium carbonate crystals, a chemical compound that is often taken as a nutritional calcium supplement but also forms biological structures such as bone skeletons. shellfish and egg shells. The crystals come together with biopolymers, which are natural polymers produced by the bacteria, and the combination forms a kind of cement that holds the simulated Martian soil particles together.
The team added nickel chloride to the mix after determining that the compound facilitated the growth of bacteria in the “soil” mix.
“Martian soil contains a lot of iron, which causes toxicity to organisms,” said co-author Aloke Kumas, an associate professor in the IISc department of mechanical engineering, said in a statement. “In the beginning, our bacteria did not grow at all. Adding nickel chloride was the key step in making the soil hospitable to bacteria.”
With the new method, the team was able to successfully make “space bricks,” but the researchers still have a lot of testing to do before such a technique is used on the Red Planet. Scientists plan to study how the bricks would respond to the Martian environment, particularly the planet’s very thin atmosphere, mostly carbon dioxide, as well as greatly reduced gravity.
According to the release, the team plans to test its bricks in a device called the Martian Atmosphere Simulator (MARS), which the researchers say will recreate Martian atmospheric conditions in a controlled laboratory environment. The team has also developed a microchip device to measure and study bacterial activity in space, according to the same statement.
One concern this study does not address is planetary protection, the concern of polluting the Earth. Scientists must ensure that spacecraft missions do not carry any unwanted bacteria or other contaminants that could cloud scientific findings or harm the world itself. (Planetary protection also requires measures to prevent a spacecraft from bringing something unintended back to Earth.)
It remains to be seen how a method like the one described in this study could work within planetary protection guidelines, which are especially strict on Mars, where spacecraft like NASA’s Perseverance rover are actively searching for evidence of past microscopic life.
This work is described in a study published on April 14 in PLOS One magazine.
Email Chelsea Gohd at cgohd@space.com or follow her on Twitter @chelsea_gohd. Follow us on twitter @Spacepointcom and Facebook.