USING THE MAGNETOSPHERIC MULTISCALE (MMS) TABLESAT IB FOR THE ANALYSIS OF ATTITUDE CONTROL AND FLEXIBLE BOOM DYNAMICS FOR MMS MISSION SPACECRAFT

摘要

The NASA Magnetospheric Multiscale (MMS) Mission consists of four spinstabilized spacecraft (s/c) flying in precise formation. To analyze the 60 meter, wire thin booms on the MMS s/c and the s/c overall dynamics, a series of table top prototypes are developed. In this paper, the authors present the MMS TableSat IB, a limited 3-DOF rotation (full spin, limited nutation) tabletop test bed of the MMS s/c, which is an improved prototype over that of the original TableSat I. The primary focus of this stage of research is to observe the effects of spin rate control on s/c dynamics, particularly with regards to flexible boom dynamics. An analytical model of the system is first obtained and a bang-bang controller is implemented to mimic the TableSat IB's pneumatic thrust system. When applied to the MMS s/c prototype, it is found that the flexible booms have a pronounced effect on the dynamics of the model s/c and on the effectiveness of the binary controller.