Hover orbit using inter-spacecraft coulomb forces

A new method for realizing hovering formation in close proximity is investigated with main focus on design of open-loop and close-loop control law. The new method utilizes inter-spacecraft coulomb forces to control relative motion. Hence, plume contamination caused by classical thrusters could be mitigated. First, a mathematical description of the Coulomb hovering formation is established by using polar coordinates. Then, an open-loop control law is provided with respect to the case of elliptic reference orbit. For the case of circular reference orbit, linearized dynamics is obtained by linearizing the model about a nominal hovering formation, and then is used to analyze close-loop feedback control law. Numerical examples are provided to demonstrate the performance of the control laws. The approach proposed in the paper could also be used in other scenario of formation flying in high earth orbit.