This paper deals with chaotic oscillation of the satellite under the infl uence of aerodynamic torque in circular orbit. Non-linear planar equation of motion of the model has been derived. Using the Bogoliubov-Krylov-Mitropolskii (BKM) method, it is observed that resonances exist. The analysis regarding stability of stationary planar oscillation of satellite near resonance frequency shows that discontinuity occurs in the amplitude of oscillation at frequency of external periodic force which is less than frequency of the natural oscillation. The aerodynamic torque plays a very significant role in changing the motion of revolution into libration or infinite period separatrix. The half width of the chaotic separatrices estimated by the Chrikov's criterion is not affected by the aerodynamic torque. It has been concluded that in the spin–orbit phase space, the regular curves start disintegrating due to aerodynamic torque (e) and the irregular mass distribution (n) of the satellite and this disintegration increases with the increase in e and n.