The European Space Agency (ESA) has successfully test fired a 3D printed platinum alloy thruster combustion chamber and nozzle. The world first test is further evidence that the 3D printing approach is a viable one for the aerospace industry, with the potential to cut costs by streamlining production methods and adding a greater level of flexibility in terms of supply and demand construction.
The 10 N hydrazine thruster combustion chamber and nozzle was printed in layers from a platinum-rhodium alloy, using a laser printing machine ordinarily used for creating jewelry. The engine was then put through 618 ignition tests during which reached a maximum temperature of 1253 °C (2287 °F). According to ESA, theses results are on a par with thrusters produced via conventional machining methods.
"The aim was to test this alternative manufacturing method as a way of reducing material costs," states ESA engineer Laurent Pambaguian regarding the project. "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."
By printing a component layer by layer, a manufacturer produces only negligible amounts of waste when compared to the standard technique, which involves creating the combustion chamber from a solid block of material. The waste, and therefore expense, of so unrefined a process mounts when one considers that Airbus Defence & Space produce 150-200 hydrazine thrusters each year and that platinum currently costs €40 (US$63) a gram.
SpaceX has also been experimenting with 3D printing. Back in 2014 the company finished qualification testing for its SuperDraco thruster, which also featured a 3D printed combustion chamber made from a nickel-chromium alloy.
With multiple agencies and commercial companies embracing the potential of 3D printing in the aerospace sector, we are sure to see the technology become heavily relied upon as we set our sights ever deeper into space. It will influence the design of future spaceships, and is likely to play a part in the construction of outposts on other planets and moons.
The next step for ESA and its partners will be to print the components out of a new alloy, platinum–iridium, which offers performance enhancements over platinum-rhodium.