TU Dresden Tests World’s First Additively Manufactured Aerospike Engine with Sustainable Fuel

Groundbreaking test paves the way for greener space exploration technologies

World’s First Hot Gas Test of Additive Manufactured Aerospike Engine
Scientists at Technische Universität Dresden, Germany, have successfully completed the world’s first hot gas test of an additively manufactured aerospike engine using a sustainable fuel combination. This achievement is part of the ASPIRER project, funded by the European Space Agency (ESA), and marks a significant milestone in space propulsion technology. The test was conducted in collaboration with the Fraunhofer Institute for Material and Beam Technology IWS, ArianeGroup, and the Warsaw Institute of Aviation. The engine was tested using a blend of highly concentrated hydrogen peroxide and kerosene, offering a more eco-friendly alternative to traditional rocket fuels.

Innovative Fuel and Modes of Operation
During the test, the engine was successfully operated in both monopropellant and bi-propellant modes. In monopropellant mode, hydrogen peroxide decomposes via a chemical catalyst, producing water vapour and oxygen—making it an environmentally friendly fuel option. In bi-propellant mode, kerosene is injected into the engine, causing the mixture to ignite spontaneously without additional mechanical components. The engine delivered 6 kilonewtons of thrust at full load—equivalent to the weight of 600 kilograms.

Overcoming Aerospike Engine Challenges with Additive Manufacturing
Aerospike engines are known for their fuel efficiency and compact design compared to traditional bell-nozzle engines, but they present challenges in terms of cooling and control. The scientists were able to overcome these obstacles using advanced Additive Manufacturing techniques, specifically Laser Powder Bed Fusion (PBF-LB). The process enabled the creation of more complex and effective engine geometries, essential for effective cooling and performance. The team also tested a newly developed heat-resistant ceramic coating for the combustion chamber elements, ensuring better durability and performance at high temperatures.

Aerospike Engines for Future Space Missions
Aerospike engines’ lightweight and compact design make them ideal for a variety of mission scenarios, such as launch vehicles, lunar exploration, and interplanetary expeditions, including missions to Mars and Saturn’s moon Titan. One of the most promising applications is in lunar modules, where the aerospike’s unique shape allows for a flatter design, simplifying astronaut operations like loading and unloading rovers. Additionally, aerospike engines offer a more sustainable alternative to hydrazine-based engines, which are criticized for their environmental and health risks.

Future Developments and Technological Challenges
Despite their advantages, aerospike engines still face technological maturity challenges. The Institute of Aerospace Engineering is exploring alternative methods for controlling these engines to improve their efficiency and reliability. The long-term goal is to address the uncertainties surrounding aerospike technology and develop it into a viable propulsion system for future space exploration missions.