Rob Postema, ESA's technical officer, delineates the pioneering nature of this project: "This new 3D printer printing metal parts represents a world first, at a time of growing interest in in-space manufacturing." He contrasts this with existing polymer-based 3D printers on the ISS, emphasizing the technical challenges metal printing poses, such as high temperatures and laser usage. This endeavor is not just about innovation; it's about ensuring the safety of the crew and the integrity of the ISS, given the constrained maintenance options in space. Successful metal 3D printing, according to Postema, would elevate the potential of in-space manufacturing, offering benefits like increased strength, conductivity, and rigidity.

Installation and Operation
Upon reaching the ISS, ESA astronaut Andreas Mogensen will oversee the installation of the approximately 180 kg printer in the European Drawer Rack Mark II within the Columbus module. Notably, the printer's operations will be remotely monitored and controlled from Earth, allowing for printing activities without requiring continuous astronaut supervision.

The project, spearheaded by Airbus Defence and Space SAS and co-funded with ESA, exemplifies the collaboration between the agency and industrial partners. Patrick Crescence of Airbus views this in-orbit demonstration as a significant step for space exploration innovation, potentially leading to more complex metallic structures being manufactured in space, a vital asset for Moon and Mars exploration.

Innovative Material and Process
Utilizing a corrosion-resistant stainless-steel wire commonly employed in medical implants and water treatment, the printer operates through a high-power laser, significantly more potent than standard laser pointers. The wire, as it dips into the melt pool, melts and adds metal to the print, an intricate process meticulously engineered to work in microgravity.

ESA materials engineer Advenit Makaya highlights the complexities of this process: "The melt pool of the print process is very small... so that the liquid metal's surface tension holds it securely in place in weightlessness." The printer operates within a sealed box to contain the high temperatures and prevent fume exposure to the crew. Additionally, venting the printer's internal oxygen atmosphere to space, replaced by nitrogen, is essential to prevent oxidation of the hot stainless steel.

Testing and Analysis
The printer's inaugural tasks involve creating four shapes, each smaller than a soda can, to test its performance. These objects will be compared with reference prints made on Earth to assess the impact of the space environment on the printing process. The noise regulations on the ISS limit printing time to four hours daily.

Post-printing, Andreas will pack the objects for their return to Earth for detailed analysis. One print will head to the European Astronaut Centre in Cologne, Germany, another two to ESA's European Space Research and Technology Centre, and the final print to the Technical University of Denmark for thermal property investigations.

Envisioning a Sustainable Space Future
This technology demonstration underpins ESA's broader goals, which include creating a circular space economy and facilitating in-situ resource utilization. Tommaso Ghidini, Head of the Mechanical Department at ESA, articulates the potential of metal 3D printing in space for future exploration activities and the sustainable use of space resources through in-situ manufacturing, repair, and possibly recycling of space structures.

Thomas Rohr, overseeing ESA's Materials and Processes Section, further underscores the significance of this demonstration, heralding it as a precursor to future space infrastructure manufacturing beyond Earth's confines.

Read more about Andreas and the science on the Huginn page.

Related Links
Human and Robotic Exploration at ESA
Space Technology News - Applications and Research