Monolite UK demonstrated that its D-Shape printer could be used to jet a binding solution into a simulated lunar soil (regolith) creating stone-like structures that would form a protective shell around an inflatable habitat.

Enrico Dini, founder of Monolite and inventor of the D-Shape printer and related printhead, said that one challenge was to find a way to print in a vacuum without the ink boiling.

"The solution was to insert the nozzle under the regolith layer. This way the chemical reaction competed with the trend to boil, sublimate or freeze," he said.

Meanwhile, architects Foster + Partners came up with the idea to mount the D-Shape printer on rovers, which would transport and then ‘print’ the regolith over the inflatable dome, rather than using a large fixed array.