Dynamic modeling and analysis of micro-vibration jitter of a spacecraft with solar arrays drive mechanism for control purposes

Pointing performances are always more demanding for the scientific and observation Space missions of the future generation. A deep study of all the possible micro-vibration sources therefore results mandatory. This article presents several tools to analyze and control the micro-perturbations induced by a Solar Array Drive Mechanism (SADM) on a spacecraft. A first tool allows the user to build the dynamic model of a spacecraft composed of different flexible appendages attached to the main body by revolute joints. A second tool provides the SimScape model of a SADM that is interfaced with the spacecraft dynamics and allows analyzing the mission pointing performances. Time and frequency studies can be performed to deeply investigate pointing performances in presence of vibrations. An example that shows the interest of the proposed tools is provided. An observation spacecraft with two flexible solar arrays and an antenna is studied. The pointing metrics are computed for two complementary solutions to the micro-vibration issue: a microstepping technique for the SADM driver and a Fast Steering Mirror (FSM) for the active control of the Line of Sight (LOS).