First metal 3D printer for space going to the ISS

The first metal 3D printer for space, developed by a consortium comprising Airbus Defence and Space, AddUp, Cranfield University, and Highftech Engineering, under a program of and funded by the European Space Agency (ESA), will soon be tested aboard the Columbus module of the International Space Station (ISS). The 3D printer was aboard a Northrop Grumman Cygnus resupply spacecraft launched Jan. 30, 2024, on a SpaceX Falcon 9 rocket from Cape Canaveral Space Force Station, Florida.

Additive manufacturing (AM) is an industrial process that has opened up new ways of looking at how parts are designed. It has many uses from the day-to-day to the surprising: from simple repairs to bio-ink implants, from printing whole houses to producing spacecraft parts.

There are already several plastic 3D printers on board the International Space Station (ISS), the first of which arrived in 2014. Astronauts have already used them to replace or repair plastic parts, since one of the major problems of everyday life in space is the supply of equipment, which can take months to arrive. But not everything can be made from plastic.

This logistical constraint will intensify on future moon and Mars stations in the next few decades. Even though the raw material still needs to be launched, printing the part is still more efficient than transporting it whole up to its final destination.

“The metal 3D printer will bring new on-orbit manufacturing capabilities, including the possibility to produce load-bearing structural parts that are more resilient than a plastic equivalent,” says Gwenaëlle Aridon, Airbus Space Assembly lead engineer. “Astronauts will be able to directly manufacture tools such as wrenches or mounting interfaces that could connect several parts together. The flexibility and rapid availability of 3D printing will greatly improve astronauts’ autonomy.”

While the process of 3D printing has been mastered on Earth, printing metal in space presents its own set of technical challenges. Sébastien Girault, metal 3D printer system engineer at Airbus, explains. “The first challenge with this technology demonstrator was size. On Earth, current metal 3D printers are installed in a minimum 10m² laboratory. To create the prototype for the ISS, we had to shrink the printer to the size of a washing machine.” This miniaturization is needed to fit the rack in which the printer will be housed aboard the ISS’ Columbus Laboratory. “At this size, we can print parts with a volume of 9cm high and 5cm wide,” Girault says.

The second challenge is safety: protecting the ISS from the aggressive printing environment caused by the laser and the heat it generates. The printer sits in a sealed metal box, which acts like a safe. The melting point of metal alloys compatible with this process can be far above 1,200°C compared to around 200°C for plastic, which implies extreme thermal control.

“Gravity management is also key, which is why we chose wire-based printing technology. The wire is independent of gravity unlike the powder-based system, which always has to fall to the ground,” Girault says.

Whether it's plastic or metal, fumes are emitted that must be dealt with by filters and captured inside the machine so that they don’t contaminate the air inside the ISS. “Safety and contamination are key drivers for us not only for the ISS, but for future use on the moon,” Aridon says.

Airbus

Is metal printing suited to a microgravity environment? This is a question the team is seeking to answer. Two printers will be used for this experiment: the flight model inside the ISS; and the engineering model on Earth. The astronauts will print four samples in space, which will be sent back to Earth for analysis. The same specimens will be manufactured using the engineering model printer.

“To evaluate the effects of microgravity, ESA and Danish Technical University will perform mechanical strength and bending tests and microstructural analysis on the parts made in space and compare them to the other specimens,” Girault explains.

Metal 3D printing on board the ISS will help improve understanding of the quality of metal printing in orbit and provide valuable insights into operating a metal 3D printer in space. Printing structural parts in space is an important step in preparing the technologies humankind will need for a sustained presence on the moon.

“Increasing the level of maturity and automation of additive manufacturing in space could be a game changer for supporting life beyond Earth,” Aridon stresses. “Thinking beyond the ISS, the applications could be amazing. Imagine a metal printer using transformed regolith [moon dust] or recycled materials to build a lunar base!”

Key figures:
Printer size: 80cm x 70cm x 40cm
Printed parts size: 9cm x 5cm
Raw material: stainless steel wire
Use: to repair/manufacture tools, mounting interfaces, mechanical parts
Parts to be printed in space: 4 specimens
Printing time per part: ~40 hours