Scientists have developed a new form of concrete that can be produced using the material available on Mars or the moon – a development that takes us one step closer to the goal of establishing a permanent settlement on Mars or the moon.
As humans target a settlement on Mars by 2030 one of the prime requirements will be to develop some form of structures – homes for astronauts – capable of protecting them from the intense radiation. Concrete-based structures could be the way to go, but to create such structures, we would need to transport thousands of tons of concrete or come up with a way to produce it there on the Red Planet.
Since it is impossible to ship tons of cement from Earth to Mars, the best bet is for humans to start making it when they arrive. The problem is that making Earth-style concrete requires tremendous amounts of heat and energy, because factories have to cook limestone to create the binding agent that holds concrete together, and energy will be in very short supply on Mars.
Scientists at NASA’s Ames Research Centre in collaboration with Stanford School of Engineering came up with a new form of concrete by turning to biology. The team involved with the project explain that living organisms use proteins to make things as tough as shells, bones and teeth, so they diverted their attention to concrete that could be bound together with a protein from bovine blood.
The protein is a fairly cheap by-product of slaughterhouses, and it is known to become very gluey when mixed with soil.
To replicate the conditions on Mars and the moon scientists combined the protein with simulated extraterrestrial soils that are similar to what’s on Mars and the moon.
And because Mars has much lower gravity than Earth, which is bad for cement mixing, the researchers did their mixing with a vacuum technology used to make the composite materials in products such as boat hulls.
The first batch of bio-concrete, according to a news release, was as strong as the concrete used for sidewalks and patios.
It also held up well to a simulated bombardment of micrometeorites, which the researchers replicated by taking the material to the Ames Vertical Gun Range and blasting it with high-speed gas particles.
For the purposes of making concrete on Mars, the idea is to create biological “factories” of organisms that are genetically engineered to produce the protein binder.
The technique could lead to more energy-efficient concrete on Earth. The production of concrete now accounts for 5 per cent of all human-generated carbon emissions, and it is the boiled limestone as the binding agent that accounts for much of that.
The new form of concrete is not ready for buildings and roads on Earth as heavy rain will degrade the new concrete over a period of years. Nevertheless scientists are optimistic about the potential and opportunities to improve the durability and efficiency, in part by tweaking the proteins as well as by becoming more efficient in production.