Let’s be clear: wanting to build a permanent base on the Moon or Mars without concrete is absurd. Wanting to build it with concrete is a huge technological, economic and engineering problem. In other words, as investment in the lunar economy grows and missions to Mars develop, the issue of concrete becomes central.

But we say little about him.

We cannot colonize space by taking cement with us. It would not only be very expensive, but very troublesome. 40,000 million tons of raw materials are consumed in construction today. 40,000 million. The idea of ​​\u200b\u200busing Earth to “mine” the entire solar system (to easily process cement) is almost ridiculous.

So there is only one option left.

How to make concrete in space? Since the 1980s, various research groups have worked on how to make concrete far from the Earth (and its water). In recent years, “viable” solutions based on sulfur or the addition of silicon to the mixture have begun to appear. But perhaps the greatest expert on the subject is in Spain.

It should not be forgotten that the laboratory at the Polytechnic University of Catalonia coordinated by Ignasi Casanova spent decades working on how to make concrete on the Moon and, in fact, the European Space Agency worked directly with the team to build the first lunar base (and to identify and evaluate the natural resources available on the surface).

Image | Aled D. Roberts and Nigel S. Scrutton

Dust, potatoes and tears. However, what drives me to talk about “cosmic concrete” today is the curious formula that has just been presented by the folks at the Future Biomanufacturing Research Hub. According to their first estimates, they found a solution almost twice as resistant as the traditional one (capable of supporting 72 megapascals compared to the usual 32). But this is not the most curious thing.

The curious thing is the recipe: a mixture of Martian regolith (the “planetary dust”), potato starch and salt. It is a process that tries to integrate the cultivation of foods such as potatoes and the manufacture of materials (in environments with very little water). The salt, incidentally, would be extracted from the tears of the settlers.

It looks like a ‘Martian’, but this same team has already accustomed us to much worse things. Not surprisingly, a few years ago they studied how to compact Martian regolith based on blood, excrement and, yes, tears. Your new idea seems at least a little more reasonable.

Although I don’t know if feasible, the truth. Because time passes and the main question remains unanswered. We’ve known for a few years that concrete can be mixed in space (it was done on the International Space Station), but the result is very different from terrestrial. Its structure is very different from the terrestrial one.

And it is that one of the great pending tasks is to know what happens to the concrete in microgravity conditions. Bubbles were formed on the ISS and it is not yet clear how this compromises the integrity of the material. Until we know what would happen on Mars, the colonists had better hold back their tears and eat their potato chips.

In Xataka | Building a permanent base on the Moon is all the rage, it’s a shame we don’t know how to build it.

Image | the martian