“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”

Norman Wagner, Unidel Robert L. Pigford Chair of Chemical and Biomolecular Engineering at the University of Delaware.

To send human exploration further into Space, staging posts will be need, perhaps like the space station, or on other planetary bodies – like the Earth’s moon.

Researchers are exploring ways to use clay-like topsoil materials from the moon or Mars as the basis for extraterrestrial cement.

To succeed will require a binder to glue the extraterrestrial starting materials together through chemistry. One requirement for this out-of-this-world construction material is that it must be durable enough for the vertical launch pads needed to protect man-made rockets from swirling rocks, dust and other debris during liftoff or landing.

Most conventional construction materials, such as ordinary cement, are not suitable under space conditions.

At the University of Delaware researchers have successfully converted simulated lunar and Martian soils into geopolymer cement, which is considered a good substitute for conventional cement. The research team also created a framework to compare different types of geopolymer cements and their characteristics and reported the results in Advances in Space Research. The work was highlighted recently in Advances in Engineering.

Geopolymers are inorganic polymers formed from aluminosilicate minerals found in common clays.  When mixed with a solvent that has a high pH, such as sodium silicate, the clay can be dissolved, freeing the aluminum and silicon inside to react with other materials and form new structures — like cement. Soils on the moon and Mars contain common clays, too.

Astronauts would only need to carry with them the materials they would need from Earth to add to those on the Moon and/or Mars to create landing pads. The researchers estimated that the amount is well within the payload range of a rocket, anywhere from hundreds to thousands of kilograms.

These results also can be used to make geopolymer cements on Earth that are better for the environment and can be sourced from a wider variety of local materials. Geopolymer cements require less water than is needed to make traditional cement, too, because the water itself is not consumed in the reaction. Instead, the water can be recovered and reused, a plus in water-limited environments from arid earthly landscapes to outer space.

Link to the study : Comparison of lunar and Martian regolith simulant-based geopolymer cements formed by alkali-activation for in-situ resource utilization

Building in Space and on other planets has long been in the works of Science Fiction writers. The Fermi Paradox, Part 2 by Duncan Lunan