Electrodynamic tethers are a promising new technology for a variety of applications ranging from
deorbiting of spent satellites and upper stages in low Earth orbits to propellantless propulsion
around any planet (inclusive Earth) with a magnetic field and a plasmasphere. However, the
continuous application of electrodynamic forces/torques over a relatively long period of time raises
dynamical issues related to the tether attitude dynamics that need to be solved for achieving longterm
dynamical stability. The paper addresses firstly the fundamentals of the dynamical motion
forced by the electrodynamic forces/torques and secondly reviews the techniques used to control the
motion generated by those forces/torques. The paper also presents the techniques that were used
successfully in simulation to control the dynamics of a tethered system designed for deorbiting
spent satellites in low Earth orbits and shows its deorbiting performance at all orbital inclinations. Copyright \ua9 European Space Agenc
