Micro Satellite Orbital Boost by Electrodynamic Tethers.

Peter Yao,Timothy Sands

doi:10.3390/mi12080916

Abstract

In this manuscript, a method for maneuvering a spacecraft using electrically charged tethers is explored. The spacecraft’s velocity vector can be modified by interacting with Earth’s magnetic field. Through this method, a spacecraft can maintain an orbit indefinitely by reboosting without the constraint of limited propellant. The spacecraft-tether system dynamics in low Earth orbit are simulated to evaluate the effects of Lorentz force and torques on translational motion. With 500-meter tethers charged with a 1-amp current, a 100-kg spacecraft can gain 250 m of altitude in one orbit. By evaluating the combined effects of Lorenz force and the coupled effects of Lorentz torque propagation through Euler’s moment equation and Newton’s translational motion equations, the simulated spacecraft-tether system can orbit indefinitely at altitudes as low as 275 km. Through a rare evaluation of the nonlinear coupling of the six differential equations of motion, the one finding is that an electrodynamic tether can be used to maintain a spacecraft’s orbit height indefinitely for very low Earth orbits. However, the reboost maneuver is inefficient for high inclination orbits and has high electrical power requirement. To overcome greater aerodynamic drag at lower altitudes, longer tethers with higher power draw are required.

Highlights

In low-earth orbits, is littered with dangerous debris monitored by the National Aeronautics and Space Administration (NASA) who together with the United
Collision avoidance is very challenging when the spacecraft at risk has no remaining fuel to perform maneuver, so this manuscript investigates the effectiveness of maneuvering spacecraft in low Earth orbit using electrodynamic tethers
Increase in orbit inclination can be attributed to cross track velocity changes caused by the Lorentz torque. This can be minimized by actively controlling the tether direction

Summary

Introduction

In low-earth orbits, is littered with dangerous debris monitored by the National Aeronautics and Space Administration (NASA) who together with the United. States Space Force issues warnings of impending space collisions [1]. Ecuador’s first and only satellite in orbit, Pegasus, collided with a Soviet-era rocket still in orbit [2]. In 2019 the European Space Agency spacecraft dodged potential collision with Starlink satellite when it maneuvered to avoid collision [3]. Collision avoidance is very challenging when the spacecraft at risk has no remaining fuel to perform maneuver, so this manuscript investigates the effectiveness of maneuvering spacecraft in low Earth orbit using electrodynamic tethers. Spacecraft in low Earth orbit have a limited lifetime due to deceleration from aerodynamic drag that eventually cause low-earth orbiting satellites to re-enter (but on oncommand). Reboost maneuvers can be conducted to keep them on station, once the propellant is expended the spacecraft loses its maneuvering capability

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