Noncoplanar Capture Trajectory Optimization in Uranian System Exploration Mission

The noncoplanar capture trajectory optimization problem involves guiding a spacecraft into a designated noncoplanar orbital plane, such as the equatorial plane, starting from a given incoming excess velocity vector. This challenge is particularly significant for the Uranian system exploration mission, due to the near-perpendicular orientation of Uranian equatorial plane relative to the ecliptic plane. This paper formulates the problem and investigates two capture strategies: the multi-impulse transfer strategy and the Titania resonant gravity-assist strategy. Global and local continuous variable optimization methods are employed to solve the impulse trajectory optimization problem, while the A* algorithm is used to address the resonant gravity-assist trajectory optimization problem. Simulation results indicate that the threeimpulse transfer strategy is more straightforward to implement and does not incur excessive Δv costs, making it a more suitable option when the initial angle is small and the transfer time is short. Conversely, the Titania resonant gravity-assist strategy offers greater Δv savings, making it potentially the better choice when the initial angle is large and the transfer time is long.