  This paper presents a novel methodology to control spacecraft swarms about
singleasteroids with arbitrary gravitational potential coefficients. This
approach enablesthe use of small, autonomous swarm spacecraft in conjunction
with a mothership,reducing the need for the Deep Space Network and increasing
safety in future as-teroid missions. The methodology is informed by a
semi-analytical model for thespacecraft absolute and relative motion that
includes relevant gravitational effectswithout assuming J2-dominance as well as
solar radiation pressure. The dynamicsmodel is exploited in an Extended Kalman
Filter (EKF) to produce an osculating-to-mean relative orbital element (ROE)
conversion that is asteroid agnostic. Theresulting real-time relative mean
state estimate is utilized in the formation-keepingcontrol algorithm. The
control problem is cast in mean relative orbital elements toleverage the
geometric insight of secular and long-period effects in the definitionof
control windows for swarm maintenance. Analytical constraints that
ensurecollision avoidance and enforce swarm geometry are derived and enforced
in ROEspace. The proposed swarm-keeping algorithms are tested and validated in
high-fidelity simulations for a reference asteroid mission.
