A group of industrial partners, including Italian space engineering firm Alta SpA, Pisa-based engineering university Scuola Superiore Sant’Anna, and renowned architects Foster+Partners, have joined the European Space Agency (ESA) to explore the feasibility of 3D printing a basecamp on the moon using lunar soil as the primary source of material.
Experts are wondering if a 3D printer might be a simple solution to building a lunar base.
If successful, this would greatly simplify the task of how to colonize the moon and, down the road, other planets, for space exploration and research purposes.
Artist’s rendering of a lunar base.
“Terrestrial 3D printing technology has produced entire structures,” explains Laurent Pambaguian, who is head of the project for the ESA. “Our industrial team investigated if it could similarly be employed to build a lunar habitat.”
How to build a lunar base
The 3D printouts are built layer by layer and right now, the study is investigating the use of regolith — lunar soil — as a building material for a lunar base that can house four people and offer adequate protection from meteorites, gamma radiation, and high temperature fluctuations.
The base itself unfolds from a tubular module that can be transported via rocket. An inflatable dome then extends from one side of the cylinder to the other, to provide a support structure for the actual building process.
When construction is underway, layer after layer of regolith is built atop the dome by a robot-operated 3D printer, creating a protective shell. To make sure it’s strong and the amount of binding “ink” being used is kept to a minimum, the shell itself is made up of a hollow-closed cellular structure which has geometry close to that seen in natural biological systems; specifically, the structure seen in bird bones.
Robot-operated 3D printers busy encasing inflatable domes in regolith.
As such, it provides the perfect combination of strength and weight.
Xavier De Kestelier, Partner, Foster + Partners Specialist Modeling Group, the team responsible for coming up with the geometry of this structure, explains the group’s take on the project:
“As a practice, we are used to designing for extreme climates on earth and exploiting the environmental benefits of using local, sustainable materials — our lunar habitation follows a similar logic. It has been a fascinating and unique design process, which has been driven by the possibilities inherent in the material. We look forward to working with ESA and our consortium partners on future research projects.”
The actual printing process
So far, the group has proven their method successful using simulated lunar soil — they were able to create a 1.5-ton building block with a 3D printer that used an array of nozzles on a six-meter frame to spray the binding “ink” on to a sand-like building material.
1.5-ton block built using 3D printer and regolith simulant.
Monolite UK supplied the D-Shape printer and developed the lunar regolith simulant. The company’s founder, Enrico Dini, explains the company’s process:
“First, we needed to mix the simulated lunar material with magnesium oxide. This turns it into ‘paper’ we can print with,” he said. “Then for our structural ‘ink’ we apply a binding salt which converts material to a stone-like solid.”
Dini adds, “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.”
Working in space
Italian space research firm, Alta SpA is now working with engineering university Scuola Superiore Sant’Anna to figure out how best to adapt 3D printing so that not only can it survive a mission to the Moon, but that the technology can operate in a vacuum.
“The process is based on applying liquids but, of course, unprotected liquids boil away in vacuum,” said Giovanni Cesaretti of Alta. “So we inserted the 3D printer nozzle beneath the regolith layer. We found small 2-mm-scale droplets stay trapped by capillary forces in the soil, meaning the printing process can indeed work in vacuum.”
Factors that must now be considered included controlling lunar dust, which is hazardous to breathe in, as well as thermal factors. Specifically addressing the latter issue, 3D printing right now works best at room temperature. On the surface of the moon, temperatures vary greatly across days and nights, which last two weeks each. One of the solutions being considered is to set up camp at one of the Moon’s lunar poles, as they offer the most moderate temperature range.
“3D printing offers a potential means of facilitating lunar settlement with reduced logistics from Earth,” said Scott Hovland of ESA’s human spaceflight team. “The new possibilities this work opens up can then be considered by international space agencies as part of the current development of a common exploration strategy.”
Story via: esa.int
Advertisement
