Trajectory Design for Proximity Operations: The Relative Orbital Elements’ Perspective

The need to preserve commercial and scientific relevant orbits in the low Earth belt asks for the active removal of inoperative satellites, which lay on slowly decaying orbits and typically present a moderate eccentricity value. Proximity operations around non-cooperative targets require the capability to execute prompt inbound/receding trajectories as well as a certain level of autonomy to react in an operationally safe fashion. The guidance and control strategies developed for docking cooperative craft can hardly be used in this case for operational reasons. As a result, the study of control solutions applicable to close-range proximity operations and suitable for spaceborne implementation is an active research field.