On July 21, ESA shared a quiet little milestone that deserves more noise than it got: astronaut Sophie Adenot floated over to a boxy machine aboard the International Space Station, opened it up, and retrieved a freshly printed piece of stainless steel. It was the fifth sample ever produced by the Metal 3D Printer Technology Demonstrator, the first metal 3D printer to operate in orbit. And tucked inside the announcement is a detail every maker who has ever watched a print fail at 2 a.m. will appreciate: the next test is an attempt to rescue a print that stopped mid-job.
What just happened 400 km above Earth
ESA's metal printer, built by an industrial team led by Airbus Defence and Space and operated with support from the French space agency's CADMOS center, launched to the ISS in 2024. Since then it has been working through a deliberate series of test prints, each one designed to stress a different aspect of printing metal in microgravity.
Three of the earlier samples have already come home for analysis at ESTEC, ESA's technical center in the Netherlands, and the Technical University of Denmark. Researchers compared them, at both the macro and micro scale, against reference parts printed on the ground with the same machine. Those results are due to be published in the coming weeks. Sample five, the one Adenot just retrieved, rode home aboard the CRS SpX-34 cargo spacecraft and is headed for testing at the German Aerospace Center (DLR) and ESTEC.
Here's the part that made us grin. While she was in there, Adenot installed a baseplate holding an element that had already been partially printed before an anomaly stopped the job. Later this year, the team will attempt a recovery procedure and try to resume that interrupted print, in orbit, remotely. If you have ever restarted a 14-hour print because of a power blip, you understand exactly how ambitious that is.
I need a replacement part for a machine whose manufacturer is long gone. Can someone 3D print one?
Yes. If you have the original part, even worn or broken into pieces, a shop like ours can 3D scan it, rebuild the CAD model, and print a functional replacement, usually in days rather than months. This is the bread and butter of our 3D scanning and reverse engineering service: discontinued brackets, obsolete knobs and housings, vintage automotive trim, robotic fixtures nobody sells anymore. The same logic driving ESA's program applies in your shop or plant. When the supply chain cannot deliver, you manufacture the part where you need it, when you need it.
Why astronauts print parts instead of packing spares
ESA points out that six cargo missions have left the ISS just since the beginning of 2026. At 400 km up, resupply is inconvenient but possible. On a Moon or Mars mission it will not be. You cannot pack a spare for every part that might break, so the answer is a machine that can become any spare.
Swap "deep space" for "discontinued product line" and the story is the same one we hear from customers every week. A vendor quotes eight weeks and a minimum order of 500 for a part you need four of. A machine sits idle because one plastic bracket cracked and the OEM was acquired twice since it shipped. Printing on demand exists precisely for the gap where inventory and lead times fail you.
My print failed halfway through. Do I have to start over?
Usually yes, a failed FDM print has to be restarted, but the reason it failed matters more than the failure itself, and fixing that root cause is what separates a frustrating hobby from a reliable process. Adhesion, moisture in the filament, thermal drift, power interruptions: every one of these has a fix. ESA's upcoming attempt to resume a partially printed metal part shows how seriously industrial teams treat print recovery, because at production scale, scrapped prints are scrapped money. It is also a good argument for handing critical parts to a shop that has already made those mistakes on its own dime. If you would rather skip the 2 a.m. failures entirely, you can upload your file and have us build and ship it.
What this means for makers and engineering buyers
Metal printing in orbit is a proving ground, and the lesson it is proving applies at every scale: additive manufacturing is becoming the fallback plan for hardware everywhere the normal supply chain gets thin. For a lot of jobs that used to demand machined metal, modern high-performance polymers like PEEK and ULTEM already deliver the strength and temperature resistance required, without the machining lead time. The space station crew is learning to trust a printer for parts their lives may depend on. Trusting one for your bracket, fixture, or housing is a much smaller leap.
By the way, if you build printers, filament, scanners, or accessories and want a working shop's honest take, we review gear hands-on as part of this series. Reach out at info@dcadditivepros.com.
Frequently asked questions
Can you 3D print a replacement part if I don't have a CAD file?
Yes. We 3D scan your original part, even if it is worn or broken, reverse engineer a clean CAD model from the scan, and print a functional replacement. No drawings or files needed.
Is a 3D printed part strong enough to replace a machined metal one?
Often, yes. High-performance polymers like PEEK and ULTEM rival or beat aluminum in strength-to-weight for many applications and shrug off temperatures that melt common plastics. We will tell you honestly when a job truly requires metal.
How long does it take to get a custom 3D printed part made?
Most single custom parts ship within days. Complex reverse-engineering jobs with scanning and CAD reconstruction typically take one to two weeks, which still beats typical vendor lead times of six to eight weeks.
How do I get a quote for a custom 3D printed part?
Email info@dcadditivepros.com with a photo, file, or description of your part. We will come back with a price and timeline, and the minimum order is just $20.