On Attitude Stabilization of Symmetric Spacecraft with Two Control Torques

It is a well-known fact in the literature of spacecraft stabilization, that a symmetric spacecraft with two control torques supplied by gas jet actuators is not controllable, if the two control torques are along axes that span the two-dimensional plane which is orthogonal to the axis of symmetry. However, feedback control laws can be derived for a restricted problem corresponding to attitude stabilization about the symmetry axis. The final orientation angle about this axis is undetermined. The purpose of this paper is to present a new methodology for constructing feedback control laws for this restricted problem, based on a new formulation for the kinematics.