One of the problems for anyone looking to build in space is that there’s a weight limit on the building materials, since launching anything into orbit is incredibly expensive. To overcome these limitations, the team chose to work with regolith, a composite material made of broken rock and dust. There’s regolith on Earth, the Moon, and other planetary bodies. To make the material malleable and printable, the team added waste plastics.
“The material is made of high basalt soil and polymer,” said Abhishek Trivedi,Autodesk’s consulting business development executive, in a company blog post. “That means it takes away the problem that comes with usage of water with Portland cement concrete, such as curing requirements, shrinkage, etc. Also, the material can be heated to just the right viscosity to enable complex, free-form design. That means you can create complex overhangs, domes, projection, roofing, etc., without needing any scaffold or supporting structure.”
To test its regolith-based ink, the team has been making Jersey barriers, a kind of modular barricade used to separate highway lanes. Jersey barriers need to be tough and sturdy in order to withstand any potential car impacts, qualities that would be important in protecting astronauts on another planet. Autodesk designed the barrier, making sure it complied with both structural and robotic-extrusion requirements. Thus far, the printing has been successful.
This isn’t the first team to work with regolith as a building material. But while most previous testing has used sintering (molding the material under high heat), the team has used a process called robotic extrusion, where the extrusion nozzle is mounted flexibly on a robot instead of being attached to the extruder, and the nozzle is connected to the extruder by a heated and pressure-resistant tube. NASA created a specially made end effect or (the tool at the end of a robotic arm) to accommodate this process.
The testing is being done at the Kennedy Space Center’s Swamp Works, an experimental center for new and emerging technology. Swamp Works collaborates with private sector and academic partners to develop tech for both outer space and Earth use. One of the highlights of Swamp Works is its enormous Regolith Bin, a 26-by-26foot “room” filled with regolith that researcher scan use to test how inventions might actually work on the surface of Mars. A recent development is the Regolith Advanced Surface Systems Operations Robot (RASSOR),which is specifically designed to help “mine” for regolith, and might work in tandem with a robot designed to use the regolith for printing.
For now, the team still needs to do more experiments, and figure out how the building material might work for larger structures here on Earth.“I think we have the right hardware, software, and material at this stage, and we have proven ourselves on a smaller scale,” Trivedi told Design News. “Next stage is to scale everything up. We are looking at a large infrastructure project with NASA. Internally, we would like to build a two-story house and compare the cost against traditional construction techniques.”