  The dynamics of a rigid, rotating, precessing, massive ring orbiting a point
mass within the perimeter of the ring are considered. It is demonstrated that
orbits dynamically stable against perturbations in three dimensions exist for a
range of rigid body rotation parameters of the ring. Previous analysis and some
well-known works of fiction have considered the stability of both rigid and
flexible, non-precessing ring systems and found that they are unstable in the
plane of the ring unless an active stabilization system is employed. There does
not appear to be any analyses previously published considering rigid body
precession of such a system or that demonstrate passive stability in three
dimensions. Deviations from perfect rigidity and possible applications of such
a system are discussed.
