Space agencies around the world are making use of 3D printing to save precious weight and costs, whether it be in space or launching off the ground. And, today, the European Space Agency (ESA) performed the world’s first hot fire tests of a 3D printed platinum combustion chamber and nozzle for a spacecraft thruster.
Steffen Beyer of Airbus Defence & Space, manager of the project, relayed, “This is a world first. The firings included a single burn of 32 minutes, during which a maximum throat temperature of 1253°C was attained. It demonstrates that performance comparable to a conventional thruster can be obtained through 3D printing.”
The combustion chamber for the 10 N hydrazine thruster was 3D printed in a platinum-rhodium alloy at the Airbus Defence & Space facility in Lampoldshausen, Germany, as a part of the ESA’s Additive Manufacturing Technologies for Advanced Satellite Thrust Chamber (AMTAC) project, with the Fraunhofer Institutes of Laser Technology and Machine Tools and Forming Technology overseeing the 3D printing process.
Though the alloy was supplied and atomized by the Heraeus company, Dr. Beyer says that a specialty alloy is being considered for the future, “Platinum–rhodium was chosen for this first phase as the most mature platinum alloy for additive manufacturing. Then, in the next phase, we will attempt to print using a new alloy, platinum–iridium, which has performance advantages. This alloy cannot easily be manufactured by traditional techniques like casting and forging, so printing is the only way it can be harnessed for space use.” Tommaso Ghidini, head of ESA Materials Technology, adds that other materials may also be 3D printed in the future, “This latest success opens the way to further developments. We aim to move to other materials, including Inconel and copper, for larger volumes, progressing to kilonewton-scale thrusters for both spacecraft and launchers.”
As the combustion chamber successfully endured over an hour of 618 ignition firings, the members involved in the project seem to believe that the 3D printing process could, in fact, be a viable method for producing spacecraft components. Laurent Pambaguian, an ESA member, said, “The aim was to test this alternative manufacturing method as a way of reducing material costs. At the start we were by no means certain it could be done, or even whether the metal powder could be prepared to the appropriate quality. For production we ended up using a laser machine normally employed for making jewellery, which is the current industrial state-of-the-art for manufacturing with these metals.”
The ability to 3D print such parts, Dr. Beyer suggests, might greatly reduce costs in producing the spacecraft’s thrusters. “Considering that platinum currently costs €40 a gram, 3D printing offers considerable future savings,” he said. “We produce 150–200 thrusters in this class per year for different customers. 3D printing should allow shorter production cycles and a more flexible production flow, such as manufacturing on demand.”
Clive Edwards, ESA telecom platform engineer, says that the combustion chamber and nozzle are only the first step. The space agency has chosen thrusters as a part of their Advanced Research in Telecommunications Systems (ARTES) programme, for their use in the satellite market. “This successful test is a major step towards the goal of full product qualification under ARTES,” Edwards explains. “Thrusters made using this technology have exceptional potential for the satellite reaction control thruster market, offering class-leading performance at competitive prices.”
With each small part that is 3D printed and survives such a test, the greater likelihood that we’ll see more and more spacecraft components made with 3D printing. Though it’s still some ways off, it’s not unlikely that, in the future, we may even see the majority of a spacecraft’s parts made with such a process.