3D printers are controversial gadgets – though their capabilities have enormous upside for their potential to improve the cost and availability of things like medical supplies, critics worry about them being used to produce things like weapons. But what about outer space? Specifically, using 3D printers to create tools and parts while in orbit? Astronauts aboard the International Space Station have done just that – they used a 3D printer to create… a part for the same printer. A faceplate, specifically.

“When the first human fashioned a tool from a rock, it couldn’t have been conceived that one day we’d be replicating the same fundamental idea in space,” Made In Space CEO Aaron Kemmer told CNet. “We look at the operation of the 3D printer as a transformative moment, not just for space development, but for the capability of our species to live away from Earth.”

Including a 3D printer on the ISS, where space is at a premium, may seem a little silly. But consider the options for astronauts when something breaks. It’s not exactly convenient to have spare parts ferried into space for them, and in the past malfunctions were handled with mechanical wizardry by engineers on terra firma. Now, instead of having to MacGyver workarounds with whatever they have available, it appears that astronauts or NASA engineers can deliver specifications for whatever’s needed directly to the printer.

The faceplate for the extruder printhead (subtly labeled “made in space”) is part of a series of experiments to see how a 3D printer functions in a micro gravity environment. The first phase, which includes the faceplate, will have the Astronauts produce benign items like coupons, labels, small tools and small spare parts. Eventually sent back to Earth, researchers will compare them with otherwise identical items printed in normal gravitational conditions. If everything checks out, Made In Space will send up a second version of the printer sometime in 2015.

“This project demonstrates the basic fundamentals of useful manufacturing in space. The results of this experiment will serve as a stepping stone for significant future capabilities that will allow for the reduction of spare parts and mass on a spacecraft, which will change exploration mission architectures for the better,” said Made In Space Director of Research and Development Mike Snyder, also principal investigator for the experiment.