Attitude stability of spinning satellites

Since the attitude instability experience by Explorer 1, many papers have been written on the effects if internal dissipation on the attitude stability of spinning satellites. In the engineering literature, stability analysis is restricted to the variational or linearized perturbational equations, despite the fact that spinning satellites are almost always critical cases in the Liapunov-Poincaré stability theory. This is certainly true in the case of dual spin satellites, which have the further complication that the linearized perturbational equations have periodic coefficients. The purpose of this note is to treat some problems of attitude stability of spinning satellites in a rigorous manner and to show that, with certain restrictions, the linearized stability analysis correctly predicts the attitude stability of spinning satellites.