Drag-free control design and in-orbit validation of TianQin-1 satellite

Drag-free control (DFC) is one of the key technologies for space-borne gravitational wave detectors. For the TianQin (TQ) project, non-gravitational disturbances on the spacecraft must be suppressed by DFC. TianQin-1 (TQ-1) is the first satellite for technology verification, whose main goal is to verify the disturbances reduction technologies. In this paper, the DFC requirement and preliminary analysis for the TQ project are introduced, and then the design and the experimental validation with the TQ-1 satellite is presented. In-orbit results show a successful validation of DFC and the residual acceleration of TQ-1 satellite has been suppressed to 5 x 10(-11) m s(-2) Hz(-1/2) at 10 mHz versus 2 x 10(-9) m s(-2) Hz(-1/2) thruster noise.