Two papers propose the use of electrically conductive tethers to remove spent or dysfunctional spacecraft from orbit around the Earth in order to reduce the hazard of orbital debris. In comparison with onboard rockets, these tethers would be more cost-effective, more reliable, and less massive. Once deployed, a tether would not require an onboard power supply. Both ends of the tether would be equipped with electrodes to make electrical contact with the ionosphere and thereby complete an electrical circuit. The orbital motion of the tether across the Earth's magnetic field would induce an electrical current in the tether. The consequent electrical heating of the tether would gradually dissipate the orbital kinetic energy of the spacecraft. It has been estimated that a typical spacecraft could be removed from orbit in weeks or months in this way, whereas the satellite might otherwise remain in orbit for years or even centuries.

This work was done by Robert L. Forward and Robert P. Hoyt of Tethers Unlimited and Chauncey Uphoff of ACTA Consulting Group for Marshall Space Flight Center. To obtain copies of the papers, "The Terminator Tether!": a low-mass technology for end-of-life deorbit of LEO spacecraft" and "The 'Terminator Tether'!": An Efficient Mechanism for End-of-Life Deorbit of Constellation Spacecraft," please contact the company via e-mail at This email address is being protected from spambots. You need JavaScript enabled to view it. or visit their web site at

Terminator Tether is a trademark of Tether Unlimited, Inc., for their electrodynamic drag tether deorbit device. MFS-26565

NASA Tech Briefs Magazine

This article first appeared in the March, 2000 issue of NASA Tech Briefs Magazine.

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