Space tethers: an overview.

Long conductive tethers orbiting around the earth or any other planet with a magnetic field develop a large potential difference between the two ends. Charging therefore occurs, and in the presence of an ionosphere significant current may flow through the wire. This basic fact can be exploited for a variety of applications, ranging from propulsion (both de-orbiting and re-boosting) to onboard power generation and scientific investigations, This brief tutorial addresses the fundamental principles of electrodynamic tethers, along with its enabling technologies, and presents past missions and future applications.