Effect of a rotor on the attitude stability of a satellite in a circular orbit

Abstract

In the gravitational field of a fixed particle, the mass center of an unsymmetrical rigid body can move on a circular orbit centered at the particle while one of the centroidal principal axes of inertia of the body remains normal to the plane of this orbit. At the same time, a second centroidal principal axis can either rotate relative to the line joining the particle to the mass center of the body, or it can oscillate about this line as a mean position. The stability of such motions has been discussed previously. The present paper deals with the following question: How does the inclusion of a symmetrical rotor affect the stability of the orbiting body? To answer this question, a general procedure for testing the stability of the motions under consideration is developed, and this procedure is used to examine a number of specific cases in detail. The results show that both beneficial and harmful effects can be produced rather easily; that is, that light, low-speed rotors can act either as stabilizers or as destabilizers.