The H10 high power density hall thruster.

Abstract

Magnetic shielding technology has extended the operating life of Hall thrusters to timescales enabling them to expand beyond missions in Earth orbit, which typically require less than 10 kh of operation, to deep-space missions requiring 10-30 kh of operation. While this has expanded potential mission capture, the specific impulse of flight Hall thrusters is still less than 2,000 s, which can limit their use on trajectories requiring velocity change greater than 10 km/s. To expand mission capture further, specific impulses greater than 3,000 s are needed over wide power throttling ratios. Towards those ends, JPL has developed a low-mass, 10-kW class, 3,000 s specific impulse Hall thruster that has demonstrated a 2:1 power throttling ratio at 800 V (~ 3,000 s specific impulse), efficiencies greater than 50% over 6:1 power throttling, and a 50:1 power throttling ratio over 0.2-10 kW. Thermal steady-state operation was reached at 15 kW, and a maximum operating power of 20 kW was briefly demonstrated. To achieve this performance requires novel approaches that can operate at power densities significantly exceeding the state-of-the-art. High power density operation is achieved in the H10 Hall thruster with an integrated, conducting wall, magnetically shielded discharge chamber assembly combined with a passive, multi-zone heat rejection system. Testing has demonstrated peak performance at 800 V, 10 kW of 457 mN thrust, 3400 s specific impulse, and an efficiency of 76%. The H10 represents a new class of high-power density Hall thrusters, enabling next generation robotic science and human exploration missions.