Asteroid Descent Trajectory Optimization With Online Thrust-Loss Identification

This study focuses on the online thrust-loss state identification and trajectory optimization problem during the asteroid probe powered descent process where thrust-loss fault occurs. First, according to the probe's thruster configuration structure, a powered descent dynamic model of the probe and a trajectory optimization model with thrust-loss constraints are established. In addition, this article proposes an online thrust-loss identification model based on the moving horizon estimation method. By combining the results of online thrust-loss identification, the trajectory replanning problem considering thrust-loss constraints is researched on the Bezier shape-based method, which can quickly generate feasible and relatively optimal trajectories. Finally, numerical simulations and analyses are performed to verify the effectiveness of the thrust-loss identification model and the probe powered descent trajectory replanning strategy proposed in this article. The proposed methods can ensure the soft-landing of the probe on a predetermined target, even if a thrust-loss fault occurs during the probe powered descent process.