Attitude equilibria and stability of arbitrary gyrostat satellites under gravitational torques.

The stability properties of gravity gradient stabilized satellites can be improved by introducing a source of constant angular momentum within the satellite. When such a satellite is designed it is important to know all of the earth pointing equilibrium orientations, since the spacecraft may inadvertently capture in an undesired orientation. A special method must then be devised to free the satellite from the trap state. A review of the literature containing solutions to various special cases of the problem of finding equilibria is presented. A method for the determination of the equilibria and stability for the most general case is given, and a numerical example is presented using the method.