Small-Time Local Controllability of the Orientation of a Spacecraft actuated by CMGs

Abstract In this paper we present an analysis of small-time local controllability (STLC) of the attitude dynamics of a rigid spacecraft actuated by two CMGs. We show that the dynamics is STLC if the Euclidian norm of the total angular momentum of the spacecraft-CMG assembly is less than that of the total angular momentum of the CMG array. This result holds in presence of singular configurations which are the focus of much attention in the literature related to CMGs.