Highly Constrained Optimal Launch Ascent Guidance

Abstract

This paper is concerned with theoretical and algorithmic development for fast generation of optimal launch ascent trajectories through the atmosphere and guidance, particularly in highly constrained missions. The theoretical investigation oers an insight into what may be called atmospheric primer vector theory, in which the critical roles of the primer vector in the determination of optimal endo-atmospheric ascent trajectories are explored in some detail. The algorithmic development focuses on ascent missions tightly constrained by aerodynamic bending moment limit. The expansion of algorithm capability aims at rapid and automated generation of such highly constrained optimal ascent trajectories. When carried on-board, this process realizes optimal closed-loop ascent guidance. An in-depth application of the theoretical and algorithmic developments in this paper is conducted using the vehicle model and mission profile of the Ares I Crew Launch Vehicle. Extensive simulations are conducted to compare optimal closed-loop with conventional open-loop ascent guidance approaches. The tests oer some rich and revealing comparisons on how each approach performs on inequality constraint observance and injected mass in the presence of winds and dispersions.