Solar Sail Coning Control to Induce Orbital Effects in Spinning Versus Non-spinning Sails

Sail attitude equilibria exist under the influence of aerodynamic, gravity gradient and solar torques. Precession of the sail normal from these equilibria causes sail normal coning about that equilibrium attitude. If the coning happens at orbit rate, wide variety of orbital effects can be induced. Past work developed a coning controller that enables orbit rate circular coning of the sail normal about the attitude equilibrium. This controller enables the sail normal vector to trace a desired coning trajectory at orbit rate. In this analysis, the performance of spinning vs. non-spinning solar sails in inducing orbital effects is studied using the coning controller. Results show that control torques required are on the order of 10−6 Nm, and it is advised to operate a non-spinning sail to avoid complex mechanisms and to maintain system robustness.