Whenever something important breaks on the International Space Station (ISS), NASA has to ensure it is replaced. This normally requires it to be sourced from the spares supply on Earth, or it has to be fabricated from scratch. Then the spare part has to be shipped up to the ISS on the next supply mission. The whole process can take weeks. So NASA has come up with an idea to speed up the manufacturing and supply of spare parts – make them ABOARD the ISS. With a 3D printer.
NASA has contracted with technology start-up Made in Space to build the printer. “Imagine an astronaut needing to make a life-or-death repair on the International Space Station,” said Aaron Kemmer, the company’s chief executive. “Rather than hoping that the necessary parts and tools are on the station already, what if the parts could be 3D printed when they needed them?”
“If you want to be adaptable, you have to be able to design and manufacture on the fly, and that’s where 3D printing in space comes in,” said Dave Korsmeyer, director of engineering at NASA’s Ames Research Center.
3D printing technology has come along in leaps and bounds since the concept was first demonstrated. Commercial sales of 3D printers have grown considerably, and some retail for very low prices. Industrial 3D printers cost many thousands of dollars and produce amazingly good items. However, all of these printers were constructed to operate (unsurprisingly) on planet Earth.
NASA intends to send a microwave-sized 3D printer to the ISS in 2014. Both NASA and Made in Space have some challenges to resolve if NASA wants to ship a printer that works successfully.
Launch into orbit – If anyone has ever watched the launch of a large rocket, he or she will be aware that it is the most dangerous part of the mission. The rocket accelerates quickly to produce high G-forces in the payload area and there can be considerable shaking. Anything sent to the ISS – people, experiments, a new printer – has to be capable of surviving into orbit.
Lack of gravity – 3D printing was developed on the surface of the Earth where gravity rules. In space, inside the ISS, there is no noticeable gravity. The 3D printer has to be designed so that it does not depend upon gravity for positioning its mechanism or the work-in-progress.
Materials used for producing parts – Most 3D printing uses one or other of various types of plastic in a spool form. The printer unspools the plastic and melts it to form a sequence of very thin layers on the printing station. However, the requirements on the ISS are that metal parts have to be manufactured. Laser-melted titanium and nickel-chromium powders are to be used to build strong components.
So this 3D printer, the size of a microwave oven, will be able to produce useful tools and vital spare parts. Instead of waiting weeks for a spare, the ISS inhabitants will be able to print one in minutes (according to NASA).