We investigate the dynamic stability of electrodynamic tethers of the type envisaged for future applications like deorbiting spacecraft and/or propulsion. In suc tethers, electrodynamic forces couple the tether natural oscillations in the orbital plane with those out of the orbital plane. The investigation is done with reference to a model where the time variation of the tether current is assumed to be given. In addition, we address both the case of a bare tether and that of an insulated conducting tether collecting current through a terminating balloon. In the linear approximation, we find possible instabilities of the tether libration modes, at moderate current values, for both the case of a bare tether and that of an insulated conducting tether. Instabilities are also found for the lateral oscillations (string modes) and the case of a bare tether. The equations obtained allow a discussion of the instability mechanisms.
Linear stability of electrodynamic tethers
2002
Abstract
We investigate the dynamic stability of electrodynamic tethers of the type envisaged for future applications like deorbiting spacecraft and/or propulsion. In suc tethers, electrodynamic forces couple the tether natural oscillations in the orbital plane with those out of the orbital plane. The investigation is done with reference to a model where the time variation of the tether current is assumed to be given. In addition, we address both the case of a bare tether and that of an insulated conducting tether collecting current through a terminating balloon. In the linear approximation, we find possible instabilities of the tether libration modes, at moderate current values, for both the case of a bare tether and that of an insulated conducting tether. Instabilities are also found for the lateral oscillations (string modes) and the case of a bare tether. The equations obtained allow a discussion of the instability mechanisms.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
