Equilibria of a charged artificial satellite subject to gravitational and Lorentz torques

TL;DR

This paper analyzes the equilibrium orientations of a charged satellite in Low Earth Orbit, considering gravitational and Lorentz torques, and explores how charge manipulation can serve as a semi-passive attitude control method.

Contribution

It develops a general model for Lorentz torque on charged satellites with arbitrary shapes and investigates equilibrium conditions and control potential.

Findings

Charge and radius influence attitude stability.

Changing charge affects Lorentz torque magnitude.

Orbit inclination impacts torque and equilibrium states.

Abstract

Attitude Dynamics of a rigid artificial satellite subject to gravity gradient and Lorentz torques in a circular orbit is considered. Lorentz torque is developed on the basis of the electrodynamic effects of the Lorentz force acting on the charged satellite's surface. We assume that the satellite is moving in Low Earth Orbit (LEO) in the geomagnetic field which is considered as a dipole model. Our model of the torque due to the Lorentz force is developed for a general shape of artificial satellite, and the nonlinear differential equations of Euler are used to describe its attitude orientation. All equilibrium positions are determined and {their} existence conditions are obtained. The numerical results show that the charge $q$ and radius $\rho_0$ of the charged center of satellite provide a certain type of semi passive control for the attitude of satellite. The technique for such kind of control would be to increase or decrease the electrostatic radiation screening of the satellite. The results {obtained} confirm that the change in charge can effect the magnitude of the Lorentz torque, which may affect the satellite's control. Moreover, the relation between the magnitude of the Lorentz torque and inclination of the orbits is investigated.