Status of Electrodynamic Tether Propulsion at NASA
- Paper number
IAC-07-C4.6.03
- Author
Mr. Les Johnson, National Aeronautics and Space Administration (NASA)/Marshall Space Flight Center, United States
- Year
2007
- Abstract
Electrodynamic tether thrusters work by virtue of the force a magnetic field exerts on a wire carrying an electrical current. The force acts in a direction perpendicular to both the direction of current flow and the magnetic field vector and is known as the Lorentz Force. Although the Lorentz Force is not new, its application to space transportation may be significant. In space, an electrodynamic tether thruster is just a clever way of getting an electrical current to flow in a long orbiting wire (the tether) so that the Earth’s magnetic field will accelerate the wire and, consequently the payload attached to the wire. The direction of current flow in the tether, either toward or away from the Earth along the local vertical, determines whether the magnetic force will raise or lower the orbit. The basic physics has been demonstrated in space by the flights of NASA’s Tethered Satellite System and Plasma Motor Generator in the 1990’s. Electrodynamic tether propulsion can be directly applied to a wide spectrum of uses in space. They include satellite de-orbit, transfer of a satellite from one orbit to another, altitude maintenance for large spacecraft such as the International Space Station, and – since it works wherever there is a magnetic field and an ionosphere – planetary exploration missions. This paper will summarize recent technology advancements in electrodynamic tether technologies and systems and their applications for science and exploration.
- Abstract document