Additive manufacturing could be used to create lunar structures from local materials
Often called 3-D printing, the emerging field of additive manufacturing has captured the imagination of a wide audience, from artists, researchers and engineers to tech-savvy consumers. Now the technology has attracted the attention of those interested in its off-world applications.
A consortium established by the European Space Agency (ESA) has demonstrated the potential for 3-D printing of a Moon base using lunar regolith as the building material. The consortium includes Italian space engineering company Alta, Pisa-based university Scuola Superiore Sant'Anna, architects Foster + Partners and 3-D printer supplier Monolite UK.
The D-Shape printer builds structures layer-by-layer using a mobile array of nozzles on a 6-meter (20-ft.) frame to spray a binding solution on to a sand-like building material. Monolite more typically uses the printer to create sculptures, and is working on building artificial reefs to protect beaches from erosion by waves.
In ESA's lunar-base design concept, a tubular module is launched to the Moon and a pressurized inflatable dome extended from one end of the cylinder to provide a support structure for construction. A robotic 3-D printer then builds up layers of regolith over the dome to provide a protective shell against meteorites, radiation and temperature fluctuations.
To demonstrate the construction concept, the team produced a 1.5-metric-ton mock-up of the hollow closed-cell wall structure for the weight-bearing catenary dome. First the simulated lunar soil was mixed with magnesium to make it suitable for printing, then a binding salt was applied to convert the material into a stone-like solid.
Smaller-scale tests were conducted in a vacuum chamber to simulate lunar conditions. The current D-Shape printer builds at a rate of 2 meters an hour, but Monolite says its next version is expected to reach 3.5 meters an hour, fast enough to complete a building in a week.