Low Thrust Augmented Spacecraft Formation-Flying

Ballistic spacecraft formation-flying with zero thrust has great utility, but it is limited to \na comparatively small set of relative trajectories. However, through the application of continuous \nlow thrust, rich new families of formation-flying trajectories can be accessed. This new and novel \nproblem provides a wide range of potentially useful alternatives to natural ballistic formationflying. \nIn this paper, the standard Clohessy-Wiltshire approximation of relative spacecraft motion \nis used to investigate the motion of a chase spacecraft about a target spacecraft which is in a \ncircular Earth orbit. Families of non-Keplerian relative motion are systematically explored, \ngenerating analytical representations of the relative motion trajectories and the required thrust \ncommands for both simple static formations and more complex new forced relative orbits. It is \nfound that the impulse, and therefore propellant, required for maintenance of such relative orbits \nis small, and so the concept of low thrust augmented formation-flying is deliverable in the near \nterm with existing thruster technology.