There are no hardware stores in space — when a part or tool breaks, getting a replacement usually means sending it up in a rocket at a cost of $10,000 a pound. At least that was the case until this week, when astronauts aboard the International Space Station used a 3-D printer to create a new tool from scratch.
The ratchet was designed and refined on a computer planetside, then uploaded to the space station, where it was double-checked for errors and finally printed out using the station's new zero-gravity 3-D printer. It's not a simple tool, either: moving parts had to be printed right into it. The plastic it's made out of won't take as much torque as metal, but it's certainly better than nothing.
This ratchet is the first hand tool to be printed in space, but the printer has been in use for nearly a month now. In late November it printed its first useful object: a replacement part for itself. The new tools and parts will be brought back to Earth later and compared with versions printed in normal gravity.