The world’s first spacecraft thruster containing 3D printed parts has been successfully tested.
The rocket engine, containing a platinum combustion chamber and a nozzle made by the additive manufacturing technique, was developed by Airbus Defence and Space in cooperation with the European Space Agency (Esa). During the testing, the thruster successfully performed 618 ignitions with the overall duration of the firing more than an hour.
“This is a world first,” said Steffen Beyer, project manager at Airbus Defence & Space. “The firings included a single burn of 32 minutes, during which a maximum throat temperature of 1,253°C was attained. It demonstrates that performance comparable to a conventional thruster can be obtained through 3D printing.”
3D printing involves building up an object in layers rather than conventionally cutting unwanted material from a solid block, meaning that much less material is needed to produce a given item.
The combustion chamber for the 10 N hydrazine thruster was printed in platinum–rhodium alloy using a laser beam applied to a metal powder bed.
“The aim was to test this alternative manufacturing method as a way of reducing material costs,” said Laurent Pambaguian, overseeing the project on behalf of Esa.
“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.”
To obtain the best quality platinum, the team used a state-of-the-art laser machine usually employed in jewellery production.
Currently, a gram of platinum sells for about €40. In higher production volumes, using a technique that minimises the amount of waste could thus make a real difference.
“We produce 150-200 thrusters in this class per year for different customers,” said Beyer. “3D printing should allow shorter production cycles and a more flexible production flow, such as manufacturing on demand.”
The platinum-rhodium was supplied by Germany’s Heraeus company, then atomised by the Nanoval firm, with the additive manufacturing process overseen by Germany’s Fraunhofer Institutes of Laser Technology, in Aachen, and Machine Tools and Forming Technology, in Augsburg.
“Platinum-rhodium was chosen for this first phase as the most mature platinum alloy for additive manufacturing,” Beyer explained.
“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.”
The project is part of Esa’s long-running Advanced Research in Telecommunications Systems programme, ARTES.
3D printed thrusters, such as the one recently tested, could be used on future satellites, offering better performance than currently available systems.