MICROSCOPE satellite and its drag-free and attitude control system

Abstract

This paper focuses on the description of the design and performance of the MICROSCOPE satellite and its drag-free and attitude control system. The satellite is derived from CNES’ Myriade platform family, albeit with significant upgrades dictated by the unprecedented MICROSCOPE’s mission requirements. The 300 kg drag-free microsatellite has completed its 2 years flight with higher-than-expected performances. Its passive thermal concept allowed for temperature variations smaller than 1 μK at the frequency of the equivalence principle test f EP. The propulsion system provided a six-axis continuous and very low noise thrust from zero to some hundreds of micronewtons. Finally, the performance of its DFACS (aimed at compensating the disturbing forces and torques applied to the satellite) is the finest ever achieved in low Earth orbit, with residual accelerations along the three axes lower than 10−12 m s−2 at f EP over 8 days.