Coulomb Forces on the Dynamics of Electrostatic (ES) Tether in Ionosphere

Abstract

In ionospheres, the orbital debris population presents a significant threat to ongoing and future space endeavors. The Electrostatic (ES) tether is an innovative tool to reduce the further buildup of space junk from abandoned satellites. We introduce the dynamics of the tether by making use of the Lagrangian formulation. We examine both quantitative and qualitative features of the Coulomb forces on the tether with high-voltage (HV) supplies, with reference to the tether’s in-plane pitch angle α, out-of-plane roll angle β, orbital polar angle θ, and orbital height h. The effectiveness of the tether to de-orbit objects is demonstrated by simulations at Low-Earth-Orbit (LEO) altitudes which are located well within the ionospheric F-layer. Results show that a rapidly applied power supply allows efficient orbit modification due to the influence of the Coulomb forces. The de-orbiting is a damped oscillatory process with final altitude between the initial one and the first (deepest) trough. Surprisingly, repeated application of the HV power following the first does not produce further altitude reduction. For a 16 kg tether system at 800 km altitude, a HV supply of 1 kV for about 30 minutes produces ∼3 km descent for a 1 km long tether.