Designed to pave the way for manufacturing of complex metal parts in space and enable further exploration of the Moon and Mars, the European-made metal 3D printer, developed by an industrial team led by Airbus Defence and Space, set off on a resupply mission yesterday (30 January).
“This new 3D printer printing metal parts represents a world first, at a time of growing interest in in-space manufacturing,” said ESA technical officer Rob Postema.
“Polymer-based 3D printers have already been launched to, and used aboard, the ISS, using plastic material that is heated at the printer’s head, then deposited to build up the desired object one layer at a time.
“Metal 3D printing represents a greater technical challenge, involving much higher temperatures and metal being melted using a laser. With this, the safety of the crew and the station itself have to be ensured – while maintenance possibilities are also very limited. If successful though, the strength, conductivity and rigidity of metal would take the potential of in-space 3D printing to new heights.”
ESA astronaut Andreas Mogensen will prepare and install the approximately 180kg device. After installation, the printer will be controlled and monitored from Earth.
“This in-orbit demonstration is the result of close collaboration between ESA and Airbus' small, dynamic team of engineers,” said Patrick Crescence, project manager at Airbus. “But this is not just a step into the future; it's a leap for innovation in space exploration. It paves the way for manufacturing more complex metallic structures in space. That is a key asset for securing exploration of Moon and Mars.”
The printer will use a type of stainless steel commonly used in medical implants and water treatment due to its good resistance to corrosion. The stainless steel wire will be fed into the printing area, which is heated by a high-power laser. As the wire dips into the melt pool, the end melts and metal is added to the print.
“The melt pool of the print process is very small, in the order of a millimetre across, so that the liquid metal’s surface tension holds it securely in place in weightlessness,” said ESA materials engineer Advenit Makaya.
“Even so, the melting point of stainless steel is about 1,400°C, so the printer operates within a fully sealed box, preventing excess heat or fumes from reaching the crew of the space station. And before the print process begins, the printer’s internal oxygen atmosphere has to be vented to space, replaced by nitrogen – the hot stainless steel would oxidise if it became exposed to the oxygen.”
Four shapes have been chosen to test the performance of the printer. These will be compared to the same shapes printed on Earth, called reference prints, to see how the space environment affects the printing process.
The four prints will all be smaller than a soft drink can in size and will weigh less than 250g. They will each take about two to four weeks to print. Print time is limited to four hours per day, due to noise regulations on the space station.
Once a shape has been printed, Mogensen will remove it from the printer and pack it for return to Earth, where it will be processed and analysed to understand the differences in print quality and performance in space.
“As a technology demonstration project, our aim is to prove the potential of metal 3D printing in space,” said Postema. “We’ve already learned a lot getting to this point and hope to learn a lot more, on the way to making in-space manufacturing and assembly a practical proposition.”
One of ESA’s future goals is to create a ‘circular space economy’, recycling materials in orbit to allow for better use of resources. Material from old satellites could be repurposed using metal 3D printers into new tools or structures, for example, eliminating the need to send them up in a rocket.
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