The houses we create on Mars and the Moon may end up being a little less hygienic than the structures we live here on Earth.
A new series of experiments has resulted in the successful manufacture of concrete that could one day be used in colonies outside the world, using a combination of simulated regolith from Mars or the Moon, a protein found in human blood and a compound found in humans. urine, sweat and tears.
These biocomposite materials are even more resistant than normal concrete and would be suitable for the construction of buildings in other worlds, if it could be achieved that astronauts volunteer to be blood bags, that is.
However, it shows that building materials can be found in the last places you plan to look, if you can think creatively.
It is not a new idea: in the Middle Ages animal blood was used to bind mortar, but it is not a solution that can be expected in the space age. New or not, it could help solve a huge problem with establishing colonies out of the world: the huge cost.
“Scientists have been trying to develop viable technologies to produce concrete-like materials on the surface of Mars, but we’ve never stopped to think that the answer might be inside us,” said materials engineer Aled Roberts of the University of Mars. Manchester and UK.
Biocomposites of Mars and Moon. (University of Manchester)
When we finally establish human settlements outside of Earth, we will have to be a little creative. Every ounce of payload of the rocket counts.
According to the latest data, it costs at least US $ 1,500 per kilogram included in a rocket launch, no matter how you get there. A 2017 report found it could cost up to $ 2 million to send a single brick to Mars.
So if we can build buildings from materials that are already on hand, that will be a huge burden, literally.
Experiments have been conducted with regolith simulants for the Moon and Mars (which is the top layer of dirt and debris on the surface of these worlds), demonstrating that these regoliths can be viable building materials. But you still have to stick them and this is where the human body could come in.
Last year, an international team of scientists found that a human urine compound called urea helps plasticize concrete, making it less brittle and flexible, which ultimately results in a stronger material that better withstands mechanical stresses. Roberts and his team have gone one step further.
Its material, called AstroCrete, uses a protein called albumin, which is found in human blood plasma, to bind concrete. Using a simple manufacturing technique, the team used human serum albumin to produce biocomposites of extraterrestrial regoliths.
These materials had compressive strengths of up to 25 megapascals, comparable to the resistances between 20 and 32 megapascals found in ordinary concrete here on Earth. The addition of urea made the material even more impressive, increasing the compressive strength of AstroCrete to 39.7 megapascals.
Mars AstroCrete printed in 3D. (University of Manchester)
Synthetic spider silk and bovine serum albumin, which could be available on Mars at some point, were also tested and could also work. But the initial supply of blood protein would be collected from the astronauts, according to the team document.
“In essence, the human serum albumin produced by astronauts in vivo could be extracted semi-continuously and combined with the lunar or Martian regular to ‘remove stone from the blood,’ to reformulate the proverb,” wrote the researchers.
Over a two-year period, six humans could donate enough albumin to build 500 kilograms of AstroCrete. According to the researchers ’calculations, the contribution of each crew member would provide enough construction material to expand the habitat and house it.
But a lot of additional research is needed. We do not know the long-term health effects of continuous plasma donation in a low-gravity, high-radiation environment. Nor do we know how much plasma can be taken from a single person sustainably and how this can affect fatigue levels.
However, it can only be a short-term solution. Once the base is established, no further donations may be needed.
“We believe that extraterrestrial biocomposites of human serum albumin could play a significant role in a nascent Martian colony,” the researchers wrote, “but will eventually be replaced by versatile bioreactors or other technologies as they mature.”
Ugh.
The research has been published in Materials Today Bio.