<h2>AAS 99-112</h2>
<h2>Earth Reentry Trajectory Parametric Analyses using the Program to Optimize Simulation Trajectories (POST)                                        </h2>
<h4>J. Foster, P. Bellini                                                                                                                                                               </h4>
Lockheed Martin Astronautics, Denver, CO                                                                                                                                  
<h2> Abstract </h2>
Earth entry analyses of lifting body vehicles have traditionally been performed using 6-DOF control law simulation tols. However, conceptual earth entry analyses can be performed using the 3-DOF POST simulation tool. Given a set of entry vehicle characteristics, 3-DOF POST can be used to conceptually analyze entry parameters such as stagnation heating rates, head loads, normal accelerations, dynamic pressures, and maximum vehicle crossrange. 3-DOF POST can also be used to analyze the entry and flyback of a Liquid Flyback Booster (LFBB) vehicle that is currently being considered for replacement of the Solid Rocker Boosters (SRB) on the Space Shuttle.