The Long-Term Performance and Life Test of the Spaceborne Rubidium Atomic Clock Under Vacuum on the Ground

摘要

The spaceborne atomic clock is one of the core payloads of the Beidou Ⅲ Global Navigation Satellite, which provides a highly stable time frequency reference for navigation satellites. At present, the Beidou Ⅲ navigation satellites are equipped with the rubidium clock and the passive hydrogen clock. This paper presents the result of a long-term performance and life test of the spaceborne rubidium clock developed by Chinese Academy of Space Technology (Xi'an), for more than 430 days under vacuum condition on the ground. During the whole test, the rubidium clock is in the normal status, stable in performance and without any failure. The frequency stability of the clock reaches 5.31 × 10~(-15)/100000 s (with drift removed), and the frequency drift rate tends to zero with the increase of working time and reaches -9.8 × 10~(-15)/day before the end of the test. Data fitting of telemetry parameters of the rubidium clock has been performed, the result shows that there would be no significant performance degradation of the spaceborne rubidium clock during the 12-year mission period of the Beidou Ⅲ navigation satellite.