Development Status and Performance Metrics of the Advanced NEXT Ion Propulsion System

The Advanced NEXT ion propulsion system is a derivative of the NEXT-C flight design, incorporating modifications that support increased thrust-to-power ratios without significantly altering the system’s mass or volume. The primary design modifications are described, which include changes to the discharge cathode assembly, ion optics, and the power processing unit (PPU) architecture. A system integration test, conducted using an engineering model thruster and a prototype model PPU, verified functionality across the entire throttle range, assessed steady-state efficiencies, and evaluated fault management. The thruster demonstrated efficiencies comparable to those of the NEXT-C system, while maintaining adequate performance margins at all test conditions. A thrust of 330 mN was demonstrated, which represents a 40% increase over the NEXT-C maximum. The PPU operated stably at all ten throttle levels, effectively managed arc faults, and maintained an efficiency between 92% and 95%. Ongoing and future work includes detailed evaluation of ion optics performance, subcomponent life testing, and environmental qualification of the PPU.