When and if we ever get astronauts back on the moon – or on Mars, for that matter – they presumably won't be bringing bags of cement or iron ore up there with them. Instead, when it comes to building things, they'll have to use the materials that are already on hand. With that in mind, scientists at Northwestern University recently set out to see what sort of items could be 3D printed using simulated lunar and Martian dust.

Led by Dr. Ramille Shah, the team members utilized a process that they previously pioneered, known as 3D painting. It involves mixing the main print material with a binding biopolymer and a series of solvents. This keeps the material in a semi-liquid state as it's being extruded by the 3D printer. Once it's been extruded, however, the solvents evaporate, leaving the polymer and the main material to set.

In this case, that material consists of NASA-approved lunar and Martian dust simulants. The finished 3D-printed objects – consisting mainly of tools and small building blocks – are over 90 percent dust by weight. They also have a flexible yet tough rubber-like consistency, allowing them to be cut, rolled, and folded as desired.

"For places like other planets and moons, where resources are limited, people would need to use what is available on that planet in order to live," says Shah. "Our 3D paints really open up the ability to print different functional or structural objects to make habitats beyond Earth."

Scientists at Washington State University have also experimented with the 3D printing of objects using simulated lunar dust. The European Space Agency, meanwhile, is looking into the possibility of 3D printing entire moon bases using lunar soil.