Buildings can be constructed in Mars with ‘Space bricks’

Researchers from the Indian Space Research Organisation (ISRO) and the Indian Institute of Science (IISc) have developed a way to make bricks from Martian soil with the help of bacteria and urea. 

About bricks made by ISRO and IISc:

• These ‘space bricks’ can be used to construct building-like structures on Mars that could facilitate human settlement on the red planet.
• The team first made the slurry by mixing Martian soil with guar gum, a bacterium called Sporosarcina pasteurii, urea and nickel chloride (NiCl 2).
  • This slurry can be poured into moulds of any desired shape, and over a few days the bacteria convert the urea into crystals of calcium carbonate.
  • These crystals, along with biopolymers secreted by the microbes, act as cement holding the soil particles together.
• This method ensures that the bricks are less porous, which was a problem with other methods used to make Martian bricks.
  • The bacteria seep deep into the pore spaces, using their own proteins to bind the particles together, decreasing porosity and leading to stronger bricks.
• In the past, the team had made bricks out of lunar soil using a similar method.
  • However, the previous method could only produce cylindrical bricks, while the current slurry-casting method can also produce bricks of complex shapes.
• Another challenge was the composition of Martian soil, which has a lot of iron that causes toxicity to organisms.
  • In the beginning, our bacteria did not grow at all.
  • Adding nickel chloride was the key step in making the soil hospitable to the bacteria.
    

Future study:

• The team is now gearing up to investigate how the atmosphere in Mars combined with low gravity affects the ‘space bricks’.
• Martian atmosphere is a hundred times thinner than that of Earth’s, and contains over 95% carbon dioxide, which may significantly affect bacterial growth, stated the release.
• To recreate conditions on the red planet, researchers have constructed a device–MARS (Martian AtmospheRe Simulator).
• As per the release, the team has also developed a lab-on-a-chip device that aims to measure bacterial activity in micro-gravity conditions.
• The device is being developed keeping in mind our intention to perform experiments in micro-gravity conditions in the near future.