Analytical Collision Avoidance with Pointing Constraints

The growing number of objects in space motivates the development of autonomous space traffic management procedures that can include operational constraints. Most spacecraft operations involve pointing a payload or antenna to receive or transmit data. Performing a maneuver with a single thruster results in the disruption of such operations because the attitude of the spacecraft must be adjusted to reorient the thruster along the desired direction. This paper addresses this problem with an analytical model for the design of autonomous impulsive collision avoidance maneuvers subject to a pointing constraint. Starting from the well-known approach of the spectral decomposition of the state transition matrix, this paper proposes an analytical model to determine the fuel-optimal maneuver that satisfies the pointing constraint. The model is then extended to include gimbal thrusters and coarse pointing constraints. The algorithm is applied to a realistic conjunction, and the results are verified against a numerical propagation, highlighting the accuracy of the model and proving its suitability for autonomous operations.