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