Prominent space agencies have a long-term agenda of setting up bases on the moon to help with their deep space explorations. Such a construction on the Earth¡¯s satellite, however, is way more difficult than on Earth. European researchers now might have found a way around it.
The research indicates that astronauts¡¯ urine could be used in the concrete of these structures. This is thanks to the urea present in the urine, which can be used as a plasticizer, an additive that can be mixed into concrete for softening and making it more elastic before it hardens.
The experiments for the research were conducted by scientists from Norway, Spain, Netherlands and Italy, in cooperation with ESA. The idea was to lower the construction cost of such a structure on the moon. On an average, every 0.45 kg transported to space from the Earth costs about $10,000. So carrying all the construction material to the moon is not a viable option.
"To make the geopolymer concrete that will be used on the moon, the idea is to use what is there: regolith (loose material from the moon's surface) and the water from the ice present in some areas," explained Ramon Pamies, a professor at the Polytechnic University of Cartagena (Murcia).
In a pursuit to use the materials found on the moon for the construction, European Space Agency (ESA) developed a material similar to moon regolith (unconsolidated rocky material). When this material is used along with urea and other plasticizers, researchers were able to produce ¡®mud¡¯ cylinders using 3D printers.
Interestingly, several tests performed on the structure afterwards revealed that the samples carrying urea were able to support heavy weights and remained almost stable in shape. Once heated to 80 degree Celsius, they were also able to pass the resistance tests that involved eight freeze-thaw cycles like those on the moon.
Urine consists of water and urea, a molecule that aids in the breaking of hydrogen bonds, thus reducing the viscosities of many aqueous mixtures. The question that looms is whether or how to extract the urea from the urine on the moon.
"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," said Anna-Lena Kjoniksen from the Norwegian University.
Which makes sense as the water present in the urine might also be useful for the mixture. If not, it might work by mixing with the water available on the moon. Either ways, it might not really be necessary to extract the urea from the urine, thus making the process much simpler for those setting up base on the moon.
There are, however, other challenges in this endeavour too. Problems such as extreme temperatures, high levels of radiation as well as meteorite bombardments can pose a great risk for any human establishment on the moon's surface. Those, however, are challenges for later!