Dynamics of a dumbbell satellite under the zonal harmonic effect of an   oblate body
  The aim of the present paper is to study the dynamics of a dumbbell satellite moving in a gravity field generated by an oblate body considering the effect of the zonal harmonic parameter. We prove that the pass trajectory of the mass center of the system is periodic and different from the classical one when the effect of the zonal harmonic parameter is non zero. Moreover, we complete the classical theory show- ing that the equations of motion in the satellite approximation can be reduced to Beletsky's equation when the zonal harmonic parameter is zero. The main tool for proving these results is the Lindstedt{Poincare's technique. 
Elbaz I. Abouelmagd, Juan L.G. Guirao and Juan A. Vera
astro-ph.EP