AAS 97-712
NOMINAL REENTRY TRAJECTORY SELECTION VIA OPTIMAL CONTROL
R.J. Baltrum, B.L. Pierson, and D.J. Chen - AeroAstro
Abstract
A method for generating nominal reentry trajectories for lift-modulating reentry vehicles is developed via an optimal control formulation. Planar point-mass dynamics are used for a coasting reentry with bounded lift control. Minimum and maximum time optimal control problems are first solved to bound the required flight time and flight envelope. The performance index contains penalty function terms used to control design limits on dynamic pressure and heating. Midpoint constraints play an important role in shaping the resulting nominal trajectory. Numerical results for the nominal reentry trajectory generated using this method are presented.