Engineers develop no-bake bricks using simulant Martian soil
Image credit: Jacobs School of Engineering/UC San Diego
Researchers from the University of California-San Diego have found that building components could be produced on Mars without the need for a kiln or specialist materials.
After the successful Moon landings, Mars became the obvious next step for manned space exploration. Elon Musk, CEO of SpaceX, has been a vocal proponent of building a settlement on Mars, and has announced plans to put humans on Mars by 2022, while national space organisations have made tentative plans for manned missions to the planet.
Without access to Earth’s varied natural resources and technologies, however, Martian settlers would need to use ingenious methods to live; to produce food, provide oxygen and build houses.
How bricks could be produced on Mars without a kiln has been a subject of debate among researchers. Suggestions include powering a kiln with a nuclear reactor, or using complex chemical reactions to turn organic Martian compounds in to binding polymers. It was while investigating how these processes could be simplified that the UC San Diego engineers discovered that no binding polymers at all were necessary.
The engineers enclosed simulant Martian soil in a flexible container - a rubber tube - and compacted it at a high pressure. This was approximately the same pressure that you would get by dropping a 4.5kg hammer one metre. The application of pressure was enough to create a brick with no heating at all.
The brick could be formed thanks to iron oxide – the compound which makes Mars the “Red Planet” acting as a binding agent. The simulant soil contained tiny iron particles coating the simulants large rocky basalt particles. The iron particles have smooth, flat facets that bind to each other under high pressure.
The process produced rounded lumps approximately an inch tall, which could be sliced into brick shapes. These bricks were stronger than steel-reinforced concrete.
This method, the engineers report, could be compatible with a form of 3d printing, as layers of soil could be laid down and compacted, before further layers are added on top. Next, the researches will focus on increasing the possible size of the bricks.
This process, which could allow astronauts to build with minimal resources, is a step towards the ambitious goal of settling humans on Mars. US President Donald Trump has signed a bill directing NASA to send humans to Mars by the 2030s, although he recently revised this goal, suggesting that a manned mission to Mars should happen during his presidency.
"The people who will go to Mars will be incredibly brave. They will be pioneers,” said Professor Yu Qiao, a structural engineer at UC San Diego and lead author of the study. “And I would be honoured to be their brick maker.”