3D printing could work on the Moon

Home Depot has yet to announce plans to open a branch on the moon, but researchers say they’ve taken a first step to making it possible for future astronauts to restock their toolbox. And yes, like so many stories in 2012, it involves a 3D printer.

A team at School of Mechanical and Materials Engineering at Washington State University says it believes it’s possible to use lunar rocks as a material for such printing.

Existing 3D printers often use a plastic similar to that which makes Lego: a laser turns the material into liquid that can be shaped and then added as a layer to the “printed” object before solidifying again.

The researchers, led by Amit Bandyopadhyay, had previously studied whether ceramic powders could be used in the same way. NASA saw the research and in 2010 sent them a “fine, black powder” that simulates the make-up of moon rock, including aluminum, calcium, iron, magnesium and silicon. It’s the same material, known as lunar regolith simulant (pictured), that NASA uses for its own studies.

Using metals in a 3-D printer isn’t unheard of, but the big challenge here was that the varying materials in the compound don’t melt uniformly. That creates the risk that using enough power to melt everything could mean some of the material turns from a viscous substance Bandyopadhyay likens to honey into a water-like liquid that is impossible to mould. Eventually the team were able to successfully process the material with a mere 50 watts of power.

In an ideal world (or rather on a smaller body orbiting it), the technology could not only mean astronauts could replace damaged equipment while on the moon, but could even cut down the amount of equipment they need to take in the first place, ideal given the need to keep weight down on lunar missions.

In practice there are some major limitations. The researchers were simply trying to see if the space rock would work in a printer and will need to work more on refining the finished product. At the moment the “printed” items are relatively weak and brittle.

Another issue is that even though we think of 3D printers as precise, the output is relatively crude in the context of a space mission. Professor Colin Pillinger of the Beagle-2 mission told the BBC the technique would only really be useful for simple mechanical parts rather than anything requiring great accuracy such as electrical components.