A Less Problem Dependent Approach for Optimal Trajectories with Singular Arcs: Application to Space Launchers

The scope of this work is trajectory optimization for space launcher problems, using Pontryagin's Minimum Principle and an indirect shooting method. Due to aerodynamic forces (drag), the considered problem may involve singular arcs, i.e. flight phases with a non maximal thrust. The chosen physical model uses tabulated data, which hinders the usual method of computing the singular control. We introduce an alternate, less problem dependent method for computing the singular control. Numerical experiments are carried out for several test problems and a typical Ariane 5 mission.