High performance of high-temperature-superconducting MPD thrusters: analytical MHD modeling and experimental demonstration.

The integration of high-temperature superconductors into electric propulsion systems, particularly applied-field magnetoplasmadynamic thrusters (AF-MPDTs), has recently garnered significant attention. However, research on low-power, high-temperature-superconducting (HTS)-based MPDTs, which are crucial for small satellites and CubeSats, remains limited. The increasing demand for compact, high-efficiency propulsion in low Earth orbit underscores the need for scalable HTS-AF-MPDT systems operating below 15 kW. Despite this, challenges such as the lack of detailed theoretical models, limited plasma diagnostics and excessive Joule heating in conventional copper magnets persist. In this work, using a downscaled version of a 25 kW HTS-based AF-MPDT, we address these limitations by developing and experimentally validating a theoretical MHD-based plasma-acceleration model for an AF-MPDT equipped with a conduction-cooled HTS magnet. The system achieves a specific impulse of 3265 s at an input power of 12 kW, more than eight times higher than traditional chemical propulsion, alongside a thrust of 320 mN and an efficiency of 25% at sub-12 kW. The HTS magnet reduces magnetic power consumption from 285 kW to under 1 kW and lowers magnet mass from 220 to 60 kg, enabling substantial improvements in system miniaturization and efficiency. These results represent the first reported demonstration of a 12 kW HTS AF-MPDT, bridging theoretical predictions with experimental outcomes and laying the groundwork for in-orbit demonstration of high-performance propulsion for small satellites.