For a long time, the space race has seen as one of its objectives the construction of human bases in places like the moon or mars. There is still a long way to go for that to happen, but little by little we can dream of it as something closer. And that is why the time is coming to think about issues that are simple on Earth, but there would be quite a headache. For example: can you wear concrete and bricks to space? The quick answer is that, by proxy, you can. But it would be especially expensive. For this reason, alternatives are explored, such as the one proposed by a team of scientists from the Manchester University, consisting of the use of one substance from blood and another from urine, sweat, and tears, to make a material similar to concrete.
As for the stone part, it would be constituted by regolith, a material that covers the surface of the Moon and Mars.
The whole process, for which much more research is still missing, can be read in a study, recently published in Materials Today Bio.
Why can’t concrete and bricks be transported?
When launching ships into space, one must carefully choose the load to be shipped on board. Especially if it is heavy.
In fact, as explained in Science Alert, it is calculated that the launch price is added $ 1,500 for every kilogram. With all this, throwing a single brick to Mars, taking into account the rest of the costs involved, could cost 2 million dollars. Bringing a concrete mixer loaded with cement on board is unthinkable.
Therefore, other alternatives should be considered, such as this one that uses substances from blood and urine to make concrete.
Blood, sweat, tears … and a little urine
The authors of this study were particularly interested in looking for something that could pegar the regolith, to get the concrete.
Already in the Middle Ages Animal blood had been used to attach mortars. In addition, a previous study showed that urea, present in urine, sweat and tears, helps make concrete more plastic, less brittle and more flexible. What would happen then if the two things were unified?
They didn’t take all the blood. Only the albumin from the plasma, as it turned out to be the component that contributed that sticky appearance to the result. The mixture of both components together with the regolith gave rise to a material similar to concrete, which they baptized as AstroCrete. His resistance to understanding reached 39.7 megapascals, something that has nothing to envy to that of conventional concrete, which is between 20 and 32 megapascals.
Where would the ingredients come from?
The study authors manufactured the AstroCrete with ingredients from two origins. On the one hand, albumin and urea from human blood and urine. Secondly, synthetic spider silk and bovine albumin.
With six astronauts, in two years you could have enough blood and urine for 500 kilos of space concrete
Both options were equally effective. However, while the latter might be viable once a settlement has been established, it would be much more appropriate initially to resort to human fluid samples.
They calculated that if they were initially shipped six astronauts, on two years these could have generated enough blood and urine to make 500 kilograms of AstroCrete. With that, at least, there would be enough to start building the buildings. But what happens next?
These scientists are aware that it is not known how dangerous it can be for the health of astronauts to donate blood in such a periodic way, with cosmic radiation and low gravity. Therefore, once that first spatial concrete is achieved, other alternatives should be considered. Send in new astronauts? Could be. However, the goal would be use bioreactors that allowed to maintain production over time.
Bioreactors are containers in which active biological systems are maintained, in order to obtain useful products for humans. For example, they are used with bacteria to obtain insulin. In this case, a way could be found to obtain large amounts of albumin and urea, without having to squeeze the astronauts as it would be done with the first inhabitants of the space base. Mind you, at least they could say they helped build the buildings with blood, sweat and tears.