Status of the THALES High Efficiency Multi Stage Plasma Thruster Development for HEMP-T 3050 and HEMP-T 30250

High Efficiency Multi Stage Plasma Thrusters (HEMP-Ts) developed by THALES Electron Devices GmbH represent a new concept for ion thrusters with unique operational and performance characteristics. The particular magnetic field topology of HEMP-Ts provides stable and erosion-free operation up to high specific impulses with a low amount of thermal losses and allows for a compact a nd robust design. The instant-on properties and the absence of discharge instabiliti es strongly facilitate the propulsion system layout. Therefore HEMP-Ts are an ideal basis for cost-effective, reliable and long-life electric propulsion systems. In the past three year s, THALES has addressed two main development axes directed towards HEMP thrusters with nominal specific impulses of 3000 s: the medium power HEMP-T 3050 and the high power HEMP-T 30250 with nominal thrust and input powers of 50 mN and 1500 W and 250 mN and 7.5 kW, respectively. The activities have been performed under support form German and European Space Agency DLR and ESA. Product development is focused on the HEMP-T 3050 capable for position and orbit control of small, mid and large-size tele com satellites. Currently, a radiation cooled HEMP-T 3050 engineering model is being developed, which represents the basic design for the HEMP-T 3050 qualification and flight models. The HEMP-T 30250 has been developed to breadboard level and demonstrates the scalability of the HEMP thruster concept towards high power and thrust levels. This paper reviews the development status, operational and performance characteristics of both HEMP-T 3050 and HEMP-T 30250 thrusters and outlines further activities towards s pace-qualification.