Survivability of Tether throughout Deorbiting

Abstract

Electrodynamic tether is a promising candidate device to remove space debris from low earth orbit. It can decelerate space debris without propellant until reentry to atmosphere. An argument of the tether is that it can be easily cut by impacts with relatively small particles. Double lined tether is proposed to improve survivability. This paper describes a method to estimate survivability of the double tether. First, fatality rates are formulated, which means how often the tether will be cut. Second, degradation of the double tether is modeled as a stochastic process. Finally, possibilities to survive from initial altitudes to atmospheric reentry can be evaluated. Result shows that the single tether is hopeless to survive though; the double tether can survive with adequate design parameters. This study gives guidelines to design parameters such as diameter, clearance and number of segments of the double tether.