ARIS advances student-built rocket engines with IRPD’s additive manufacturing support

As the 2025 ARIS (Academic Space Initiative Switzerland) rocketry cycle concludes, the student teams behind the HEPHAESTUS and HERMES projects credit their industrial partner, IRPD AG, with enabling significant progress in bi-liquid propulsion system development.

The collaboration focused on the additive manufacturing of high-performance engine components using Inconel 718, a nickel-based superalloy renowned for its resistance to high temperatures and mechanical stress. Through IRPD’s selective laser melting technology, the ARIS team produced critical parts for the HEPHAESTUS engine series, supporting a rapid and iterative development process.

The program began with the Mk.I engine, which served as a test platform for validating ignition procedures, propellant flow, and startup behavior. It became ARIS’s most powerful bi-liquid engine at the time and introduced the first EthaLOx configuration—using ethanol and liquid oxygen—featuring a pintle injector manufactured with IRPD’s assistance.

Development culminated in the Mk.IV engine architecture, incorporating improvements in thermal regulation, structural robustness, and overall performance. IRPD manufactured two Mk.IV units: one designed for instrumentation-heavy testing, and another optimized for flight with a lower mass profile.

Project leads emphasized that the additive manufacturing partnership was essential to reaching this level of technical maturity. “Having the ability to prototype and test components with such speed and quality was a decisive factor in the success of our propulsion efforts,” said a spokesperson from the ARIS propulsion team.

The teams plan to continue advancing their propulsion systems and noted that future development cycles will build on the lessons and capabilities gained through this partnership with IRPD.