The European Space Agency (ESA) is currently exploring the possibility of establishing a permanent lunar base with the aid of 3D printing technology. The space agency and Foster + Partners, the London-based architecture firm that worked closely with the agency in the exploration of the project, have released a video outlining how they envision a future mission to construct a moonbase may unfold.
Whilst the idea of a frontier settlement on Mars has captured the imagination of the general public, establishing a base on the Moon would be a much more attainable prospect and could even serve as a proving ground for a mission to the Red Planet.
For mankind to establish a permanent outpost beyond low-Earth orbit, certain safeguards are required to protect us from the harsh conditions that prevail beyond the defensive shield of our planet's atmosphere. On a body such as the Moon that only has a minimal atmosphere, an outpost would be exposed to a plethora of dangers including solar radiation and micro-meteoroid impacts.
To mitigate these dangers, ESA has been investigating the potential of using rover-like automatons to 3D print a moonbase around an inflatable habitat dome located at the lunar south pole. Previous experiments carried out by the agency and its partners have already demonstrated that 3D printing such an outpost is indeed viable with lunar materials.
The experiment used basaltic rock extracted from a volcano in central Italy to mimic the qualities of lunar soil with a fidelity of 99.8 percent. Using this material, the team printed a 1.5 tonne (1.7 ton) building block with a hollow closed-cell structure. It is hoped that such building blocks may one day be instrumental in creating a permanent outpost on the Moon.
"3D printing offers a potential means of facilitating lunar settlement with reduced logistics from Earth," states 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."
The process of transforming the "lunar" material into a usable building block began by mixing the basaltic rock with magnesium oxide. This created a paper-like substance that was then manipulated by a 6 m (20 ft) mobile printing array supplied by Monolite UK Ltd. The block was then built up layer by layer and sprayed with a salt-based binding solution that turned the sand-like construction rock hard.
Italian firm Alta SpA, working in conjunction with engineering university Scuola Superiore Sant'Anna, took the project one step further, examining how the terrestrial based 3D printing technique would fare in a vacuum. "The [3D printing] process is based on applying liquids but, of course, unprotected liquids boil away in vacuum," explains Giovanni Cesaretti of Alta. To remedy the issue, the team inserted nozzles distributing the binding solution inside the lunar soil, dispensing 2 mm droplets, small enough to bind the material without boiling away.
ESA and its partners are now looking to refine the process, including exploring the possibility of using concentrated sunlight to melt the lunar material into a solid state, which would remove the need to use a binding solution.
The following video from Foster + Partners illustrates the firm's vision of a mission to print a 3D moonbase.