Astronauts will fix their gear using thin air

3D printing is crucial for establishing long-term settlements beyond Earth. This technology can transform basic inputs like plastic or metal powder into any tool or item an astronaut might need, making it a true game-changer. The underlying chemistry is complex, with applications ranging from building structures to making everyday plastic goods.

New research from the University of Arkansas explores a vital aspect of metal 3D printing. Scientists discovered they could save millions on Mars missions by simply utilizing the planet's atmosphere to help create metal parts. Their study focused on selective laser melting (SLM), a common method for printing stainless steel.

On Earth, atmospheric oxygen makes printed metals brittle. To counter this, 3D printers use an inert "shield gas," usually argon, to keep oxygen away. Argon is costly and almost non-existent on Mars, meaning it would have to be shipped from Earth at great expense. The new paper proposes a different approach: using Mars' own atmosphere as the shield gas.

This seems counterintuitive, as Mars' air is primarily carbon dioxide (CO2), which contains oxygen. However, experiments showed that while CO2 didn't perform quite as well as argon, it was acceptable for many non-critical metal parts, like hinges. For instance, argon achieved 98% shape retention, while CO2 managed 85%, far superior to regular air, which produced useless parts.

The reason CO2 works is that at the laser's high temperatures, though CO2 breaks down and releases oxygen, the *amount* of oxygen forced into the molten metal is significantly lower than in Earth's air. This reduced interaction limits oxidative damage, making the resulting parts functional.

This finding has broader implications. Companies on Earth could save money by using cheaper CO2 instead of expensive argon for certain metal prints, even if the visual quality is slightly lower. For astronauts, however, function trumps aesthetics. Using Mars' readily available atmosphere for manufacturing is an ingenious way to leverage local resources, bringing us a step closer to permanent Martian settlements.

Reference
by Andy Tomaswick, Universe Today , How astronauts will fix their gear using thin air
phys.org  Available at :https://phys.org/news/2026-01-astronauts-gear-thin-air.html
(Assessed: 20th January 2026)