<h2>AAS  96-168</h2><h2>ADVANCED LAUNCH SYSTEM TRAJECTORY OPTIMIZATION</h2><h4>P. D. Burkhart and D. G. Hull, The University of Texas at Austin</h4><h2> Abstract </h2>The purpose of this study is to calculate the angle of attack and bank angle histories that maximize the payload to orbit of the Advanced Launch System using the shooting method and to compare the optimal control results with suboptimal control results. The physical model is summarized, and the formulation of the two point boundary value problem is discussed. Suboptimal control results are used to start the shooting method, but ad-hoc methods are needed to achieve convergence.  Converged state and control results are presented and compared with those of suboptimal control. The two approaches compare well in that only 0.1% more mass is placed in orbit by the optimal control.<br><br>