Constrained trajectory optimization for lunar landing during the powered descent phase

To design the more accurate trajectory of a soft lunar landing, the constraints on the powered descent sub-phase, such as a breaking phase, an approach phase, a terminal descent phase, have to be considered. In this paper, the trajectory optimization of the lunar landing was performed considering constraints on the sub-phase of the powered descent phase. To convert the optimal control problem, the Legendre pseudospetral (PS) method was used and C code for feasible sequential quadratic programming (CFSQP) was used as the NLP solver.