In order to build a house as a living base for manned exploration and colonization of Mars in the future, we are studying to make concrete-like building materials from the surface soil (weathered layer) of Mars. Using weathered layer to make concrete requires bonding materials, but it is difficult to get them on Mars. Researchers at the University of Manchester in the United Kingdom have come up with a way to use protein in astronauts' blood and urea obtained from urine as adhesive materials. It is said that higher compressive strength can be obtained than ordinary concrete.

When manned exploration of Mars and future colonization of Mars become possible, how should we obtain materials for human habitation? From the cost point of view, the method of transporting concrete and iron from the earth is unrealistic. If building materials are sent from the earth to Mars, it is estimated that even a brick will cost more than RMB10 million.

If the existing materials on Mars can be used for buildings, the transportation problem will be solved. On the moon, the "weathering layer sintering material" which uses the moon concrete with weathering layer on the moon surface such as sand and dust to heat and solidify the weathering layer powder at low temperature is being studied. However, it is difficult to make concrete in vacuum, which requires a lot of energy to sinter the weathered layer, and each has its own advantages and disadvantages.

At present, scientists are also studying building materials made of Martian weathering layer. NASA is developing the technology of manufacturing weathered building materials by using 3d printers, but according to the current research, adhesive materials must be transported from the earth, which will account for a considerable part of the weight of materials that can be transported to Mars.

If all materials can be found on Mars, but cement can't be found, that would be ideal. Therefore, researchers at the University of Manchester in the United Kingdom have developed a biomaterial for concrete on Mars, which can be brought to Mars without oppressing the payload. The paper was published in Materials Today Bio, a professional magazine of materials engineering, on September 1 day, 20265438.

Protein from biology has the function of an adhesive for fixing substances. Having said that, the method of carrying a large number of livestock that can be extracted in the early days of Mars colonization will produce the same payload problem as carrying cement. Therefore, researchers look for adhesive materials from astronauts themselves. That is the most abundant protein in the blood, human serum albumin. Healthy adults can produce 6 ~12g albumin every day with amino acids as raw materials.

In fact, albumin is extracted from blood, and bio-concrete is made of Martian simulated soil. The results show that its strength reaches 25 MPa, which is equivalent to ordinary concrete. The researchers named this material "AstroCrete".

Then urea was taken out from the discharged urine and added to AstroCrete, and its strength reached 40 MPa, which was higher than that of ordinary concrete. Researchers estimate that if six astronauts live on the surface of Mars for two years and provide albumin, they can produce more than 500 kilograms of AstroCrete.

Even if a small amount of bio-concrete can be made from blood in the laboratory, it is still a question whether it can really be used for Mars colonization. Astronauts have a great physiological burden, even if they agree in advance, there will actually be a lot of pressure. Albumin may not be collected due to injury or nutritional problems.

As an alternative material, bovine serum albumin, like human serum albumin, can be made into concrete from Martian weathering layer. If cattle can colonize Mars in the future, it is also possible to use bovine albumin, and goats and rabbits have the same function. Food such as milk can be produced, and leather can also be used to increase the significance of Mars resources. However, it is difficult to add larger and heavier animals to the payload. In addition, it is technically possible to culture only albumin, but it is necessary to transport the culture device-bioreactor to Mars.

If a bioreactor can be realized that doesn't compress the payload too much, then the protein of squid's ring teeth, mussels, barnacles and other protein-binding materials can be expected. Another biomaterial is spider silk. In this paper, spider silk protein called "spider silk" is used as the bonding material of Mars concrete. Like albumin, the Martian weathering layer may also make concrete. So far, the International Space Station (ISS) has also carried out basic research on spider silk culture. In the colonial era of Mars, this technology may blossom and become a building material.

Perhaps astronomical concrete made of human blood will only stay in the laboratory. If it can be proved that biomaterials can be used as building materials in the universe, it is more necessary to cultivate the same materials than to extract blood from astronauts living in harsh environments. Human serum albumin can be extracted from rice endosperm and used for medical treatment. If this technology can be applied to the universe, it is also possible to produce food and concrete materials with rice in plant factories on Mars.