Building on Mars and the moon
The scientists outlined their method for using clay-like topsoil materials to build future space habitats. “If we’re going to live and work on another planet like Mars or the moon, we need to make concrete. But we can’t take bags of concrete with us—we need to use local resources,” said Norman Wagner, Unidel Robert L. Pigford Chair of Chemical and Biomolecular Engineering at the University of Delaware.
The researchers successfully converted simulated lunar and Martian soil into geopolymer cement, which is considered a suitable alternative to traditional cement. They published their findings in the journal Advances in Space Research.
Geopolymers are inorganic polymers formed from aluminosilicate minerals. They are found in common clays all over the world. When they are mixed with a solvent with a high pH, the clay can be dissolved, freeing the aluminum and silicon inside to react with other materials. This then allows the creation of cement.
Geopolymer mixture can withstand rocket blasts
The researchers set out to find out if simulated moon and Martian soils could be activated in a similar fashion using geopolymer chemistry. They mixed many different simulated soils with sodium silicate and cast the resulting geopolymer mixture into molds to observe the reaction. Specifically, they wanted to see if slight differences in chemistry would have a big impact on the overall strength of the resulting material.
In their paper, they explain that they were able to make materials in little cubes that have the compressive strength required to withstand the strength of a rocket blast. More investigation is, of course, needed to see how the material will hold up in space conditions. Based on their results though, the researchers laid out a few pointers that could help develop materials in space. Chemical composition and particle size, for example, can play a crucial role in material strength.