OPTIMAL AEROASSISTED INTERCEPT TRAJECTORIES AT HYPERBOLIC SPEEDS

The paper considers the optimization of earth-based multi-stage rocket interceptors with very short flight times and long ranges. The objective is the minimization of the launch mass as a function of interceptor design variables such as: stage size, engine bum times and the angle-of-attack program. Because of the demanding target conditions the payload reaches hyperbolic speeds and the centrifugal force greatly exceeds the gravity force. The minimization of launch mass shows that the needed down-force on the payload is best provided by negative aero-dynamic lift. The description and numerical computation of such aeroassisted optimal trajectories is the principal goal of the paper. Topics treated include: a model for the multistage interceptor, the formulation of the optimization problem, the derivation of a universal curve which is an accurate model fo