Scientists have discovered that the urea present in the human urine could one day be used as a building material to make structures on the Moon. As per new study published in the Journal of Cleaner Production, urea could be used in making concrete for lunar structures. This comes at a time when researchers across the world have already been conducting experiments to determine which materials could be used to build structures on the Moon. Now, why do we need urine to make structures on the moon? Let's look into it.
The surface of the Moon is a lot harsher than the surface of the Earth. Even the conditions are much more extreme, mainly due to the lack of an atmosphere. From extreme temperatures ranging from 120 degrees Celsius to -130 degrees Celsius, radiation, and the meteorite showers - since there is no atmosphere to burn up any space rocks that might crash, people living on the Moon will have to endure much worse conditions than on Earth. Even the buildings they live in will have to withstand such extreme conditions.
Hence, in this new study, researchers from Spain, Italy, Norway, and the Netherlands, in association with the European Space Agency (ESA), conducted a number of experiments that tested the plasticisers for materials like concrete or lunar regolith (loose material from the Moon's surface), including urea from human urine. Plasticiser is a substance added to materials like concrete to make it flexible before it hardens. To test urea as a plasticiser, the team 3D printed small cylinders from a material similar to lunar regolith. They tested the material with urea and other plasticisers.
The samples that used urea as a plasticiser were able to support heavy weight, remain stable, and keep their shape. They were soft enough to build a structure and were able to bear heavy loads shortly after being printed without losing shape. Even in terms of compressive strength, scientists said that the samples that used urea as the plasticizer, showed a "continuous slight increase in compressive strength."
Now, although the experiments have shown urea to be a great plasticiser for building material on the lunar surface, the scientists are still looking at how they will extract urea from urine. They are also looking at other components of urine for being used for this purpose.
"We have not yet investigated how the urea would be extracted from the urine, as we are assessing whether this would really be necessary, because perhaps its other components could also be used to form the geopolymer concrete," Anna-Lena Kjøniksen, one of the researchers from Norway said in a statement.
"The actual water in the urine could be used for the mixture, together with that which can be obtained on the Moon, or a combination of both," Kjøniksen said.