AAS 95-448

Combined Launch Trajectory and Vehicle Design Optimization

V. Dorairajan and B. L. Pierson, Aerospace Engr. & Engr. Mechanics, Iowa State University, Ames, IA

Abstract

This paper highlights the advantages offered by combined vehicle design and trajectory optimization. The problem is to maximize the payload capability of a two-stage launch vehicle launched into a circular low-earth orbit of 100 nm. In this study, some vehicle parameters such as nose cone half-angle, vehicle slenderness ratio, stage propellant loading, are simultaneously optimized with the trajectory parameters stage burn times, booster kick angle, and steering programs. An empirical aerodynamic model is used. The standard planar, point-mass equations of motion over a non-rotating, spherical earth with inverse-square gravity field and an exponential atmosphere are used to model the vehicle dynamics. This optimal control problem is then approximated as a parameter optimization problem and solved using sequential quadratic programming.