  Asteroid body-fixed hovering problem using nonideal solar sail models in a
compact form with controllable sail area is investigated in this paper. The
nonlinear dynamic equations for the hovering problem are constructed for a
spherically symmetric asteroid. The feasible region for the body-fixed hovering
is solved from the above equations by using a shooting method. The effect of
the sail models, including the ideal, optical, parametric and solar photon
thrust, on the feasible region is studied through numerical simulations. The
influence of the asteroid spinning rate and the sail area-to-mass ratio on the
feasible region is discussed in a parametric way. The required sail
orientations and their corresponding variable lightness numbers are given for
different hovering radii to identify the feasibility of the body-fixed
hovering. An attractive mission scenario is introduced to enhance the advantage
of the solar sail hovering mission.
