Abstract:This paper presents a nonlinear optimal control schemefor the three-dimensional retrieval process of an electrodynamic tetheredsatellite system in an inclined orbit. The Legendre pseudospectral algorithmis used to acquire an optimal trajectory to guide the subsatellite into afinal position close to the spaceship under mission-related constraints. Theoptimal control is discretized and solved with the nonlinear programming.The scheme is verified with the numerical simulation. The results shows thatthe control action is carried out by only adjusting the tensional andelectrodynamic forces in the tether.