Scientists are exploring the construction of a lunar base with astronaut urine

 In the movie "Mars Rescue", astronauts trapped on Mars successfully planted potatoes using fertilizer made from human waste, and finally successfully returned to earth. Now, researchers have discovered that the astronaut's urine may have other uses. Recently, in an article published in the Journal of Cleaner Production, scientists from Norway, Spain, the Netherlands and Italy collaborated with the European Space Agency to carry out several experiments to verify that urine can be used as Plasticizer to use. Plasticizer is an additive that can be incorporated into concrete to make it more flexible. In other words, the astronaut's urine may be used to build a lunar base.

In-place material collection on the moon

Human exploration of outer space is gradually progressing. NASA, ESA, and China National Space Administration plans to establish a lunar base in the next few decades. This is an important step in the human space exploration program. . As the plan advances, mankind will have the opportunity to explore farther planets, such as Mars. However, there are still some problems that need to be solved to establish a lunar base, such as higher radiation on the moon, extreme temperatures, meteorite rain, and a more difficult logistics problem: how to make building materials on the moon.

It takes about 10,000 US dollars to transport 0.45 kg of objects from the earth to space. It would be very expensive to establish a base on the moon in this way. So the space agency is considering the use of raw materials on the lunar surface, and even astronaut urine as raw materials to establish a base. One of the authors of the experiment, Ramón Pamies, a professor at the Polytechnic University of Cartagena in Spain, explained: "To make concrete on the moon, our idea is to use local materials: lunar differentiation layer (a loose matter on the surface of the moon) and water in ice."

Pamies added, “More importantly, through this study, we found that wastes such as urine from lunar base personnel can also be used. The main components of urine are water and urea, and urea molecules can break hydrogen bonds, thereby reducing water. The viscosity of the mixture. "

The researchers used a material similar to the lunar weathering layer developed by ESA, plus urea and various plasticizers, and then used a 3D printer to create various "concrete" cylinder samples. They used X-ray diffraction to perform various analyses on the samples and compared the results.

Figure | Samples and 3D printers (Source: Shima Pilehvar et al. / "Clean Production Magazine")

Urea may be used as a plasticizer

Experiments conducted at Østfold University College (Norway) showed that the samples carrying urea were relatively heavy and the shape remained almost stable. The researchers tested the resistance of the samples after heating to 80 ° C. They found that after eight freeze-thaw cycles similar to the lunar surface environment, the resistance of the samples even increased.

Figure | Sample U (left) contains 3% urea, and sample N (right) contains 3% ordinary plasticizer naphthalene (Source: Shima Pilehvar et al./ "Clean Production Magazine")

Norwegian University researcher Anna-Lena Kjøniksen said, "We have not studied how to extract urea from urine, and we are evaluating whether it is really necessary to do so, because other substances on the moon may also be used to make concrete. Urine water in the liquid can be used alone or in combination with the water on the moon. " Scientists emphasize that further testing is needed now to find the best building materials for the construction of the moon base and then mass production using 3D printers.