Hybrid propulsion system for formation flying using electrostatic forces

Propulsion, path planning and control of spacecraft formations in Geostationary Earth Orbit (GEO) and other high Earth orbits present significant challenges to engineers. An innovative hybrid propulsion system for close-proximity (<50 m) formation flying is presented using electrostatic forces and standard electric/ion thrusters. The Sliding Mode Control (SMC) strategy generates the required inter-spacecraft forces based on the equivalent product of spacecraft surface charges. Collision-free aggregation and formation is realized using the Artificial Potential Field (APF) method. Simulation is performed to prove the efficacy of the proposed control, path planning and hybrid actuation schemes for close-proximity spacecraft formation flying in GEO and other high Earth orbits.