Approximate optimal LEO transfers with J2 perturbation and dragsail

An indirect optimization method is applied to orbit transfers in LEO, considering almost circular orbits and the influence of J2 perturbation. An approach based on Edelbaum’s approximation is employed to solve transfers with change of semimajor axis, inclination and right ascension of ascending node. The spacecraft employs electric propulsion either alone or in combination with a drag sail that can be deployed and retracted. The proposed formulation is simple and effective and is capable of treating both minimum-time (thruster is always on) and minimum-propellant (coasting arcs are introduced) problems, while also dealing with the presence of altitude constraints. Convergence to the optimal solution is fast and straightforward, making the proposed approach suitable for the preliminary evaluation of large sets of available transfers (e.g., multiple debris removal).