Reliability Study On COTS Used In Space Radiation Environment

The space projects in the world have a heavy demand on commercial off-the-shelf (COTS) components due to COTS'higher performance, lower cost etc. However, the shortage of a quality characteristic on high reliability leads to unreliable and risky COTS based space system, especially in the space radiation environment. The methodology of reliability system engineering is utilized to solve these problems.First, the space radiation environment simulation platform was initially implemented based upon studies of space radiation environment and COTS'radiation effects and failure modes in the environment.Second, the notion of"COTS'reliability assurance test (CRAT)"was brought forward and emphatically developed. Based on the analysis of COTS'reliability assurance, the principium and the flow of COTS'upscreening, and the process of constituting upscreening specification were investigated. And the formulae for calculating the thermal stress and test time were researched using Arrhenius model.Last, with total ionizing dose effect tests about microcontroller and flash chips carried out, the dose threshold was determined, and the effectiveness of standby redundant design and intermittent operating mode was proved in reducing the risk. Methods of"nondestructive screening"and"radiation screening"were initially studied, and nondestructive screening regression model was established and validated. The relative error of the model was small enough to meet the need in engineering.The feasibility of these methods was validated through tests and studies. The research of this topic provides valuable roadmap and lays a certain extent foundation for using COTS in high reliable space projects.