A Phase Dependent Reliability Model of a Stationary Plasma Thruster Propulsion System

As an efficient alternative propulsion technology to chemical thrusters, Electric Propulsion (EP) systems like the Stationary Plasma Thruster (SPT) used on geostationary satellites built at SSL, a Maxar Technologies company, continue to gain popularity in the commercial spacecraft industry. This paper presents a reliability analysis of a standard SPT propulsion system with 2 Power Processing Units (PPU) and 4 SPTs, starting from reliability model development, by taking into account phase dependency with dynamic duty cycles. To study impact of unit failure rate values to the system reliability, Birnbaum’s component importance measures are examined. A numerical example is presented with pros and cons. And a proposed path-forward is outlined.