Reliability assessment and life prediction of ion thruster

Abstract

Ion thruster, as a new space propulsion system, has the characteristics of high reliability and long life. Moreover, it is usually ion thruster tested subject to the testing time and cost. Therefore, the mentioned phenomenon leads to great difficulties in the reliability analysis of ion thruster. Motivated by the problems, the main failure mode and mechanism is firstly analyzed for ion thruster. The relationship model between the groove erosion depth and the operating time is established by a linear function. Meanwhile, considering most of thruster will experience several different given power due to the mission requirements, the cumulative damage method is used to estimate the useful life of thruster. Then, the lifetime distribution of ion thruster is given and the one-sided confidence intervals of life and reliability are derived. Finally, an engineering example is given to illustrate the effectiveness of the proposed model.