Short tethers for electrodynamic thrust

The operational advantages of electrodynamic tethers of moderate length are becoming evident from studies of collision avoidance. Although long tethers (of order of 10 kilometers) provide high efficiency and good adaptability to varying plasma conditions, boosting tethers of moderate length (- 1 kilometer) and suitable design might still operate at acceptable efficiencies and adequate adaptability to a changing environment. In this paper we carry out a parametric analysis of the performance of 1-km long boosting tethers, to maximize their efficiency. We also discuss the possible use of multiple, parallel such tethers for keeping thrust high when length is decreased. We then estimate the survivability of short tethers to micrometeoroids and orbital debris. Finally, a few considerations are made on the dynamic stability of electrodynamic tether systems versus length.