If equipment breaks down on the moon, ordering a replacement part through the mail isn't exactly an option. But what if astronauts could simply print out what they need, using local materials?
It's not possible to plan for every eventuality - and, even if it were, the enormous cost of carrying cargo means that spaceships have meaner baggage allowances than Easyjet.
So to try and help, a team of Washington State University scientists has developed a 3D printer that could use melted moon rock as its raw material to produce vital tools and spare parts.
"It sounds like science fiction, but now it’s really possible," says professor Amit Bandyopadhyay.
NASA researchers provided Bandyopadhyay and his team with 10 pounds of raw lunar regolith simulant, an imitation moon rock that is used for research purposes.
The team was concerned about how the moon rock material - which is made of silicon, aluminum, calcium, iron and magnesium oxides - would melt. But it turned out to behave similarly to silica, allowing the researchers to build a few simple shapes.
"It doesn’t look fantastic, but you can make something out of it," says Bandyopadhyay.
While moon rock won't do for every purpose, additives brought from Earth could make it more versatile, the researchers say, for example by making the material stronger.
"It is an exciting science fiction story, but maybe we’ll hear about it in the next few years," says Bandyopadhyay. "As long as you can have additive manufacturing set up, you may be able to scoop up and print whatever you want. It’s not that far-fetched."