Dynamics of Deorbiting of Low Earth Orbit Nano-satellites by Bare Electrodynamic Tether

Abstract

This paper studies orbital and librational dynamics of deorbiting a nano-satellite by a bare electrodynamic tether. The orbital motion and tether libration are modeled by considering multiple space environmental perturbations including the current-induced electrodynamic force, atmospheric drag, Earth’s oblateness effect, irregularity of Earth’s geomagnetic field, ambient plasma density affected by the variation of geomagnetic and solar condition, solar radiation pressure, and lunisolar gravitational attractions. Approximated analytical and numerical calculation methods of the perturbation torques are provided. Numerical simulations are conducted to study the electrodynamic tether’s orbital and libration motion during deorbiting. The effect of tether libration on the induced voltage is also analyzed. Nomenclature E r a = acceleration of the Earth EDT r a = acceleration of the electrodynamic tethered system a = semi major axis of the orbit A = cross section area of the electrodynamic tether d A = projected area of nano!satellites for atmospheri c drag r