Remote Sensing for Planar Electrostatic Characterization Using the Multi-Sphere Method

Abstract

Applications like the Electrostatic Tractor (ET), remote sensing of space debris objects, or planetary science investigating asteroid charging, benefit from a touchless method to assess the electrostatic potential and charge distribution of another body. In the ET, accurate predictions of the force and torque between a passive space object and tug spacecraft are critical to ensure a robust closed loop control. This paper presents a novel, touchless method for determining both the voltage and a Multi-Sphere-Method (MSM) model which can be used to determine the charge distribution, force, and torque on a nearby space object. By means of potential probes, Remote Sensing for Electrostatic Characterization (RSEC) can be performed. Here the space tug shape and electrostatic potential is assumed to be known. The probes measure the departure from the expected potential field about the tug and determine an MSM model of the passive object’s potential distribution. This paper outlines a method for estimating the voltage and charge distribution of a neighboring charged spacecraft undergoing a planar rotation given measurements of voltage over a full rotation. Assuming knowledge of the tug spacecraft’s voltage and charge distribution, the rotation rate and distance to the debris, numerical simulation results illustrate that the constructed model of the debris can be characterized within a few percent error.