SMILE project: First hot firing tests of LOX/kerosene rocket engine with 3D-printed injector

DLR press release


Within the SMILE project, first hot firing tests were successfully conducted in early November 2017. The measured data shows very good mixing and combustion efficiencies of the printed injector in combination with a water-cooled, metallic combustion chamber. The SMILE project aims to design a cost-effective launch vehicle for the delivery of small satellites into sun-synchronous orbits (SSO). In order to fulfil commercial, operational and technical requirements, multi-disciplinary design optimisation processes are applied.

DLR’s Institute of Structures and Design is responsible for developing a reusable liquid rocket engine. The design is thereby based on ceramic engine components which are specifically qualified due to their high thermal shock resistance and high-temperature applicability. Thus, innovative design methods become possible allowing such systems to be reused. Furthermore, advanced manufacturing technologies are used for the highly complex injector head component designed by DLR. Partner 3D Systems printed the prototype injector for LOX/kerosene operation via additive layer manufacturing on a ‘ProX DMP 320 metal printer’ at its manufacturing site in Belgium.

For experimental testing, DLR provided an integrated setup. Partner PLD Space set up and operated a high-pressure rocket engine test bench in Teruel, Spain.



Next steps within the SMILE liquid rocket engine development focus to replace metallic wall structures of the combustion chamber by fibre-reinforced, ceramic materials as intended. Further goals are to optimise both the injection and ignition system as well as to improve the overall engine design.

This work is performed within the ‘SMall Innovative Launcher for Europe’ project. SMILE, coordinated by NLR, has received funding from the European Union’s ‘Horizon 2020 research and innovation program’ under grant agreement No 687242. Further info on SMILE can be found on www.small-launcher.eu.