Heterogeneous Surface Multisphere Models Using Method of Moments Foundations

Abstract

Spacecraft can charge naturally to tens of kilovolts in geosynchronous orbit due to their interactions with the space plasma and the sun. This charging causes forces and torques that can perturb the orbits of uncontrolled debris objects. Charging is also being investigated as a form of touchless actuation in an active charging multicraft formation. The multisphere method (MSM) was recently developed to yield fast numerical approximation electrostatic forces across charged bodies. The surface MSM (or SMSM) implementation assumes a homogenous distribution of equally sized spheres across the surface. This paper details the relationship of the SMSM and the established method of moments (MOM) solution, highlighting similarities and differences. Furthermore, a new MOM-based SMSM development process is presented that allows for a heterogeneous surface sphere distribution while achieving more accurate electrostatic force evaluations as compared to prior work. Numerical examples illustrate the accuracy of the heterogeneous SMSM technique.