“…The paper is organized as follows: the dynamical model is briefly introduced in Section 2, including the differential equations of motion for the three orientations of the dipole considered. Several configurations about the equilibrium points computed in [4] (consisting of a single or multiple spacecrafts, with either the same or different charges), are analysed in Section 3, including the effects of initial errors in their location. In Section 4, we consider the controllability of the linearised system around the equilibrium points, and we propose a linear quadratic regulator (LQR) feedback control law for the formation keeping, where the charge of the spacecraft is the only control variable.…”