Analysis of the Dynamics and Choice of Parameters of an Electrodynamic Space Tether System in the Thrust Generation Mode

Abstract

The dynamics of an electrodynamic space tether system operating in the thrust generation mode in a near-Earth orbit are analyzed. The motion of the tether system relative to the center of mass is described using mathematical models of various complexity with and without elastic vibrations of a weightless and weighable electrically conductive tether under the action of a distributed load from Ampere forces in Earth’s magnetic field. The tether system is designed to alter the orbital parameters of small spacecraft and nanosatellites. The evolutionary motion of the system around the center of mass with a change in its parameters and strength of current is analyzed. It has been found that the system behavior substantially depends on the sign of the moment of the Ampere force relative to the center of mass of the system. The change in orbital parameters is assessed using a system of differential equations in osculating elements for which the averaging procedure is used. An analytical solution of the averaged system is obtained for sufficiently small values of current; this solution allows one to preliminarily select the tether system parameters. The results of calculations using simplified models are compared with numerical calculations carried out on a model with distributed parameters in which the cable is represented by a set of material points.