Mars entry trajectory optimization using DOC and DCNLP

This paper addresses the issue of Mars atmospheric entry trajectory optimization by use of the desensitized optimal control (DOC) and Direct Collocation and Nonlinear Programming (DCNLP). Firstly, desensitized optimal control methodology is adopted to reduce the sensitivity of terminal state variables with respect to uncertainties and perturbations along the trajectory, in addition to optimizing the original performance index. Then, Direct Collocation (DC) method is used to transform the optimal control problem into Nonlinear Programming (NLP) problem which can be easily solved using the SNOPT software package. Monte Carlo simulations of error analysis show that the sensitivity of terminal state variables with respect to uncertainties and perturbations is significantly reduced, leading to improved entry precision.