ISRO, IISc researchers develop 'space bricks' made from lunar soil for future habits on the moon
The bricks are made from a combination of urea, lunar soil and guar resin extracted from guar beans.
Researchers from the Indian Space Research Organisation (ISRO) and the Indian Institute of Science (IISc) have developed a sustainable process of making bricks on the moon. The process uses urea, lunar soil, bacteria and guar beans in the making of these bricks, which could be useful in building self-sustaining structures on the moon someday.
"The process involves extracting lunar soil and using bacteria and guar beans to harden it (soil) into brick-like structures for habitation on the moon in the future," a researcher of the city-based science institute told IANS.
Many countries have hopes of sending humans to the moon, Mars and the outer planets of our solar system. India, too, is also part of this race. ISRO is working on sending the first human being to orbit in the Gaganyaan mission, slated for 2022. Currently, four cosmonauts are being trained in Russia for the mission.
However, colonizing other planets is a mission idea to be explored, and NASA's Artemis mission is the furthest so far in exploring the same. However, travelling to space is expensive and so is sending one pound of material to space which costs around Rs 7.5 lakh with today's technological capabilities.
If sending materials from Earth is not a viable option, using things that are found on the moon is the next best bet.
The team working on this project call them “space bricks” and believe it could be used to create habitation structures on the moon. This will be a cost-effective method and will also be a sustainable option as compared to cement.
“It is really exciting because it brings two different fields — biology and mechanical engineering — together,” said Aloke Kumar, Assistant Professor in the Department of Mechanical Engineering, IISc in a press statement.
The process of creating these bricks involving using urea – which can be readily found in human urine – and mixing it with lunar soil are the raw materials. Adding guar gum that is extracted from guar beans, the researchers were able to make the bulk of these bricks.
Another option is using a bacterium called Sporosarcina pasteurii, they found, which produces calcium carbonate crystals through a metabolic pathway called the ureolytic cycle. According to the IISc statement, this bacterium uses urea and calcium to form these crystals as by products of the pathway.
“Living organisms have been involved in such mineral precipitation since the dawn of the Cambrian period, and modern science has now found a use for them,” says Kumar.
The bacteria were mixed into the lunar soil and then urea and calcium was added to it along with the guar gum. After a couple of days, the bricks formed were "found to possess significant strength and machinability."
The researchers were able to mould the material into any shape using a simple lathe machine. This makes the recipe flexible to use in a variety of shapes by casting, said Koushik Viswanathan, Assistant Professor in the Department of Mechanical Engineering, IISc in a statement.
"This capability could also be exploited to make intricate interlocking structures for construction on the moon, without the need for additional fastening mechanisms,” he added.
The findings of this study have been published in the journal Ceramics International.
In another study headed by Rashmi Dikshit, a DBT-BioCARe Fellow at IISc, the team of researchers looked at another bacterium option - Bacillus velezensis instead of the Sporosarcina pasteurii. Since Sporosarcina pasteurii is expensive - a vial of this bacterium can cost Rs. 50,000 - the researchers looked at Bacillus velezensis as it is locally available and cheapers but has similar properties. The findings from this study have been published in the journal PLOS One.
"We have quite a distance to go before we look at extra-terrestrial habitats. Our next step is to make larger bricks with a more automated and parallel production process," says Kumar.
Meanwhile, the researchers are looking to improve the strength of these bricks and test them under varied loading conditions like impacts and possibly moonquakes.
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