Use of a Genetic Algorithm to Assess Relative Motion in Highly Elliptic Orbits

This paper examines final rendezvous between two vehicles in highly elliptic orbits. The range of eccentricities addressed is 0.6 to 0.9. Due to the varying orbital speeds of the two vehicles, the relative motion during elliptic rendezvous is highly dependent on initial conditions and differs significantly from the relative motion seen in circular rendezvous. The character of the motion has important implications for operational and safety considerations. The development of relative motion targeting and propagation procedures that output relative coordinates in a suitable curvilinear coordinate system is discussed. These procedures are subsequently combined with a genetic algorithm optimization that is used to globally characterize the solution space. Results of genetic algorithm studies are presented and a fuel-optimal family of solutions is identified for further study and characterization.