I have always wanted a 3D printer but never quite found a good enough reason to get one. Seeing that NASA are now 3D printing metal is even more tantalising than a plastic 3D printer. However, thinking about it, surely it is just a computer controlled soldering iron! I’m sure it’s far more advanced than that! Turns out that the first print really wasn’t much to right home about, just an s-curve deposited onto a metal plate! It does however prove and demonstrate the principle that a laser can liquify stainless steel and then deposit it precisely in a weightless environment.
Arguably 3D printers have revolutionised manufacturing and prototyping industry. The invention of them has been attributed to Chuck Hull who in 1983 but it’s more true to say he laid the foundations. Hull developed a technique known as stereolithography which involved creating 3D objects by curing thin layers of a photopolymer with UV light. The 3D printers that are commercially available came 5 years later in 1988.
NASA and ESA have been interested in 3D printing in space to make repair/improvement engineering far cheaper, sustainable and timely. Instead of waiting for parts to be shipped up to the ISS. To that end there has been a more conventional plastic 3D printer on board the ISS since 2014 because a 3D printed replacement is far simpler and more cost effective. Indeed ESA are trying to create a circular space economy to recycle materials already in orbit. It makes far more sense to repurpose existing materials in orbit – such as metal from old satellites – to make new tools or parts removing the need for rocket launches to transport them.
The metal printer that is now on board the International Space Station employs stainless steel wire being fed onto the medium being printed upon. A high power laser which is a million times more powerful than a laser pointer then heats it up melting a small section. As the steel wire feeds into the melt pool it melts, adding to the metal, making it slightly raised.
Unlike a 3D printer you may have (or I may be trying to justify) which you can control from your own computer, the printer on ISS is controlled entirely from the ground. The crew do have tasks however, they have to open a nitrogen and venting valve before the printing can start. I guess it’s almost the equivalent of putting the paper in your printer at home!
The printer was developed by a team led by Airbus under the ESA Directorate of the Human and Robotic Exploration contract. It arrived on the ISS in January 2024 where the 180kg printer was installed in the ESA Columbus Module.
The next step for the printer is to print four shapes that have been chosen for full-scale 3D printing. They will then be returned to Earth for analysis and comparison against reference prints already created in normal gravity. The teams hope to explore how microgravity impacts 3D printing. Two of the 3D printed parts will go to the Materials and Electrical Components Lab at ESTEC in Netherlands. The other two will go to the European Astronaut Centre at the Technical University of Denmark.
Source : First metal 3D printing on Space Station