Future Moon colonists should be able to use lunar rocks to create tools or spare parts, according to a study.
US researchers have used a 3D printer to make small objects out of melted simulated lunar rocks.
They say the technique could help future missions to minimise the weight and the expense of carrying materials into space as a digital file would be enough.
But one expert says such a printer would have to be extremely precise.
In 2010, Nasa asked a team from Washington State University to see whether it was possible to use lunar rocks for 3D printing.
It supplied the researchers with simulated Moon rocks, or lunar regolith simulant, containing silicon, aluminium, calcium, iron and magnesium oxides.
Many hundreds of kilograms of Moon rocks were collected during Nasa missions, but the scientists did not use them because they are considered a national treasure in the US.
Lunar regolith simulant is commonly used for research purposes at Nasa.
It sounds like science fiction, but now it's really possible, said Prof Amit Bandyopadhyay, the lead author of the study, published in the Rapid Prototyping Journal.
His team created simple 3D shapes by sending a digital file or scan to a printer which then built the items layer by layer out of melted lunar regolith, fed via a carefully controlled nozzle to form a shape. The process is known as additive manufacturing.
A laser was used to melt the material.
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, said Prof Bandyopadhyay.
The research demonstrates the latest advances in 3D printing technology, which is already in use in medicine, fashion, car manufacturing and other industries.
