Optimal on-off cooperative manoeuvers for long-term satellite cluster flight

When a group of satellites is equipped with a particulary simple propul-
sion system, e.g. cold-gas thrusters, constraints on the thrust level and total
propellant mass renders cluster-keeping extremely challenging. This is even
more pronounced in disaggregated space architectures, in which a satellite
is formed by clustering a number of heterogenous, free-flying modules. The
research described in this paper develops guidance laws aimed at keeping
the relative distances between the cluster modules bounded for long mission
lifetimes, typically more than a year, while utilizing constant-magnitude
low-thrust, with a characteristic on-off profile. A cooperative guidance law
capable of cluster establishment and maintenance under realistic environ-
mental perturbations is developed. The guidance law is optimized for fuel
consumption, subject to relative distance constraints. Some of the solutions
found to the optimal guidance problem require only a single maneuver arc
to keep the cluster within relatively close distances for an entire year.