The European Space Agency (ESA) is exploring the possibility of 3D printing lunar habitats in space.  Architects Foster + Partners have designed the off-world structures and they are working with UK-based Monolite to explore the possibility of using lunar soil as the build medium.

"Terrestrial 3D printing technology has produced entire structures," said ESA's Laurent Pambaguian.  "Our industrial team investigated if it could similarly be employed to build a lunar habitat."

Foster + Partners designed a dome shaped habitat that will protect the inhabitants from space radiation and micrometeoroids.

"As a practice, we are used to designing for extreme climates on Earth and exploiting the environmental benefits of using local, sustainable materials," said Xavier De Kestelier of Foster + Partners Specialist Modelling Group.  "Our lunar habitation follows a similar logic."

The actual printing will be accomplished with Monolite's D-Shape.  The D-Shape uses an array of printing nozzles on a 6m frame.  The nozzles spray a binding solution onto the building material, hardening it as it prints.  Monolite has experimented with a variety of building mediums in the past, but targeting lunar soil is a first for them.

The D-Shape Printer

"First, we needed to mix the simulated lunar material with magnesium oxide.  This turns it into 'paper' we can print with," explained Monolite founder Enrico Dini.  "Then for our structural 'ink' we apply a binding salt which converts material to a stone-like solid."

While they haven't actually tried the process with lunar soil yet, tests on the simulated soil have gone well.  They produced a 1.5 ton building block as a demonstration.  The building block incorporates a hollow, closed-cell structure designed to maximize strength while minimizing weight.

A large block of 3d printed simulated lunar material

Monolite's Enrico Dini believes that they may even be able to speed up production of the lunar habitats in the future.  "Our current printer builds at a rate of around 2m per hour, while our next-generation design should attain 3.5m per hour, completing an entire building in a week."