Life Prediction Method of On-board Hydrogen Clock under Multiple Mechanisms

Abstract

As the on-board time reference of the navigation system ranging, the on-board hydrogen clock is the core part of the payload of the satellite navigation system, and its lifetime directly determines the duration of the navigation satellite mission. In order to meet the demand for life prediction of on-board hydrogen clocks, this paper expounds the composing and design of the hydrogen clock and focuses on the factors affecting the lifetime. In general, the factors include: the hydrogen supply period of the hydrogen component in the vacuum module, the period of the vacuum system to maintain a specific vacuum degree, the degradation speed of the bulb coating, the atomic preparation ability including the ionization device of the ionization bulb and the ionization circuit, the performance of the magnetic shielding and other key factors. In addition, the key performance indicators are also considered. The telemetry data and the test data of the key components on the ground are comprehensively utilized to evaluate the lifetime at which the relevant performance parameters reach the threshold. Based on the random failure, degradation, consumption and the key performance indicators of the hydrogen clock, a multi-mechanical and competitive life prediction method is proposed. The case study shows that the new method can be used to get the more dependable results of life prediction.