A spacecraft propulsion system includes a plurality of wires (102) or other electrically conductive elongated members deployed from a main body (101) into respective radial directions. An electric potential generator (605) generates an electric potential on board the main body (101). The electric coupling between the electric potential generator (605) and the elongated members is controlled (604) so that all or some of the elongated members (102) assume a high positive potential. An auxiliary propulsion system (203) rotates the main body around a rotational axis (502) that is perpendicular to the radial directions, thus creating a centrifugal supporting force to the elongated members.