The European Space Agency’s (ESA) 3D metal printer has produced the first metal part ever created in space. It arrived aboard the International Space Station (ISS) in mid-February, delivered by the Cygnus NG-20 resupply ship.
Manufactured by Airbus Defence and Space SAS, it weighs 180 kg. The printer uses stainless steel wire that is melted at around 1,400 °C by a laser. The material is deposited in successive layers until the desired part is created. That’s the theoretical explanation.
A first test under high surveillance
In fact, the first test of the metal 3D printer on board the ISS required time and infinite precautions. Located in the European Columbus laboratory of the ISS, it was placed in a closed box to avoid exposing the astronauts to the fumes and heat it gives off. In addition, before each print, the box must be placed under vacuum and then filled with nitrogen so that the stainless steel does not oxidize.
The test phase began in May with a commissioning procedure during which each subsystem of the 3D printer was tested: the stainless steel deposition system, the laser, the wire feed, the coordination of the printer’s moving plates. A first 2D print of a letter “S” validated this step.
Four metal parts manufactured on board the ISS
Next came the 3D printing sequence of the first of four metal parts that will be manufactured aboard the ISS. It was not a foregone conclusion and we had to face certain uncertainties. “, explains Anthony Lecossais, chief engineer at Airbus. The ISS is a special place, with a high level of security. We also have a complex operations scenario to ensure that we can reliably control and monitor the payload remotely via the ISS telecommunications links. »
The printing operations were supervised from Earth by the French space agency (CNES) and Airbus. Of all the 3D printing parameters, layer height requires the most attention. “, explains Airbus in its press release. The height of each layer is adjusted individually, knowing that there were 200 in total. Another constraint, the printer being noisy, it can only operate a few hours per day so as not to disturb the crew.
The pieces will return to Earth for analysis
By mid-July, after printing about 50 layers, the teams had acquired enough information to accelerate the printing pace. On August 21, astronauts Sunita Williams and Jeanette Epps retrieved the first sample from the metal 3D printer.
Photo credit: © Nasa
« This first sample will allow ESA to characterize the effect of the microgravity environment on the 3D metal printing process, by comparing the mechanical properties of this part produced in space with the same part produced in our laboratory in Toulouse. It also allowed us to test the practical aspects of the operation. ” explains Anthony Lecossais.
Crucial autonomy for future distant missions
In total, the metal 3D printer will produce four types of parts, each weighing 250 grams. The parts will be returned to Earth and then compared to replicas and analyzed at ESTEC, the European Astronaut Center and the Technical University of Denmark.
Manufacturing of parts, tools, repairs… 3D metal printing will play a key role in future long-duration deep space missions by providing crucial autonomy. Exploration of the Moon and Mars will increase mission duration and distance from Earth, and resupply of spacecraft will be more difficult,” states the ESA. « Additive manufacturing in space will provide autonomy to the mission and its crew, providing a solution to manufacture necessary parts, repair equipment or build dedicated tools, on demand during the mission, rather than relying on resupply and redundancies.
