Research and Innovation in Space Electric Propulsion and Plasma Diagnostics at German Aerospace Center

Kurzfassung

Research at DLR Göttingen addresses the challenges of modern space missions through an integrated approach that combines advanced plasma thruster development, high-fidelity testing, and standardized diagnostics. Central to these efforts is the operation of a dedicated large-scale vacuum facility, known as the Simulation Facility for Jet Propulsion in Göttingen – Electric Propulsion (STG-ET), which replicates space conditions while mitigating facility effects to enable precise characterization of thrust, efficiency, and plume behavior. A primary research pillar is the development of next-generation electrodeless thrusters, such as the ALFVEN (Advanced Linear Field Vector Excitation Network) and DEEVA (DLR Electrodeless ECR Via Microwave Plasma Accelerator). These concepts utilize radio-frequency (RF) and microwave (MW) power to eliminate lifetime-limiting components such as electrodes and neutralizers, thereby significantly reducing sputtering and erosion caused by chemical reactions or ion bombardment. This electrodeless feature provides superior compatibility with alternative propellants — including water, iodine, argon, or even air. Such propellant flexibility is a key enabler for Very Low Earth Orbit (VLEO) missions, where thrusters could potentially utilize atmospheric intake as propellant to compensate for aerodynamic drag. In addition to the development of the electric propulsion concept, a series of engineering and development activities related to the advanced plasma thruster development is also proceeding in parallel, including the development of an RF/MW power amplifier, a power controller, a processing unit, and a flow control unit to support the small satellite missions. DLR Göttingen is also equipped with test and verification capabilities for electric propulsion devices from the low-power to tens-kilowatt range, including precise thrust measurement down to the sub-mN range and a series of plasma measurement techniques to investigate the fundamentals of plasma discharge and acceleration processes. The modular diagnostic platforms integrated within STG-ET provide standardized interfaces for instruments such as Faraday probes and Retarding Potential Analyzers, which are essential measurement tools to understand the behavior of electric propulsion and for optimizing thruster efficiency. By combining these advanced concepts with rigorous testing and diagnostics, DLR Göttingen can contribute to accelerating the next-generation electric propulsion development for future space exploration. This paper will summarize the DLR’s activities in the field of electrodeless plasma thruster development and the relevant infrastructure and test capabilities for enabling the scientific research relate to the electric propulsion physics and engineering.