Formation flight line of sight guidance

The purpose of this work is to develop simple control laws based on optical measurements for formation flying. Use of optical navigation is not new and has been used in the past, particularly in the areas of target tracking, interception, rendezvous and docking. Although much work has been done in this field, there are still unique challenges in space applications not faced in the more conventional applications. In this work a leader–follower satellite configuration is considered with the satellites in low Earth orbits. A body fixed configuration for the optical and propulsion system in the chaser satellite is imposed to simplify the actual system implementation for small satellites. Only accelerations normal to the relative line of sight between the satellites are employed. These control laws enable an active chaser satellite to transfer autonomously from one relative elliptical orbit to another, using continuous low thrust engines.

► Simple formation flying control laws based on optical measurements are developed.
► A body fixed configuration is used for the optical and propulsion systems.
► Chaser satellite uses continuous low thrust engines.
► Only accelerations normal to the relative line of sight are employed.
► Chaser satellite transfers autonomously from one relative elliptical orbit to another.