The step to the moon is already a success over 50 years ago – now the person should be there soon, permanently walk: The NASA, the European space Agency (ESA) and its Chinese counterpart are planning the construction of moon bases in the coming decades. Later, more distant targets are in the sights of space travel: One day man might colonize Mars, the vision of the future.

In the implementation of the plans are enormous challenges to overcome: settlements on the moon must be able to withstand the extreme temperature fluctuations, meteorite bombardment and intense radiation. It is, therefore, asked a very durable building material. Of the earth should get away with it but as little as possible. Because of the Transport of about 0.45 kilogram of cargo into space with rocket technology, existing about 10,000 dollars. The construction of a lunar base with terrestrial Material would be extremely costly and logistically difficult to implement.

Also, the moon colonists need to go to the little astronauts

for this reason, the space agencies want to use the resources of the moon as best as possible, and also the substances obtained in the framework of the manned missions there, necessarily. In the space has been used in this context, the potential of the astronauts-urine successfully. The substance can be used, among other things, for the production of drinking water or for the fertilization of vegetables. An international team of researchers now presents a further possibility of use for this Golden resource of the space.

In the course of their study, the researchers have explored the extent to which the urine contains urea which is suitable as a plasticizer in the manufacture of concrete on the moon. How do you explain, could be made of the Geopolymer material from the loose Material on the lunar surface-the so – called Regolith, and the water that comes from the well-known ice deposits of the celestial body. In order to give the moon-the concrete before Curing certain forms, could come to a special 3D printer to use, the scientists report.

A special 3D-printer produces the test objects. (Image: Shima Pilehvar et al./ Journal of Cleaner Production)

plasticizer for 3D-printed moon-concrete

the starting mixture must, however, be supple – therefore, a plasticizer is necessary. For this reason, the urine moved into the sights. “The two main ingredients of this body fluid are water and urea. This is a molecule that can break hydrogen bonds and thus the toughness of many aqueous mixtures is reduced,“ explains Co-author Ramón Pamies of the Polytechnic University of Cartagena.

Whether urea can fulfill this function in the production of lunar concrete, tested by the researchers using the ESA-developed Materials, similar to the lunar regolith. As an additive material in addition to urine, various plasticizers are used, which are already technically used for the manufacture of Geopolymeren. As a control Material was used without the addition of a plasticizer. From all of the test materials, the researchers were using a special 3D printer cylinder, which you studied then.

As reports showed the addition of about three per cent, of urea, a similar beneficial effect on the concrete material, such as the use of other plasticizers. Without the accessories of the printer could produce, however, no well-structured cylinder, showed the Tests. After curing, the control proved to be Structure even as a little resilient. The urea-concrete-cylinder was, however, stable as the other objects of comparison. Also to repeated freeze-thaw cycles, how they are to be expected on the moon, showed the Material is resistant. “Overall, urea has promising properties as a plasticizer for the 3D printing of a lunar Geopolymeren,” the scientists write.

The researchers now want to explore the potential of the substance. “Perhaps it is not even necessary to extract the urea from the urine. Because maybe his other main ingredient could be used also for the production of Geopolymer concrete,” says Co-author Anna-Lena Kjøniksen from the Norwegian Østfold University College in Halden. “The urine liquid could be used for the mixture, together with the water that can be won on the moon“.

In addition, the scientists want to test now, what are the effects of vacuum conditions on the 3D printing of urine-moon-have concrete and how powerful the Material is: So you want to examine about the extent to which it can resist Meteorite impacts or the colonists can protect against the radiation in space.

source: FECYT – Spanish Foundation for Science and Technology, journal article: Journal of Cleaner Production, doi: 10.1016/j.jclepro.2019.119177

*The contribution of “Curious: the moon bases from “urine-concrete”” is published by Contact with the executives here.