Abstract: Trajectory optimization is one of the key factors in scheme planning of the new type of hypersonic gliding reentry vehicles. The optimal gliding reentry trajectories are researched based on the physical programming (PP) method, which is capable to obtain tradeoff solution of multi-objective optimization problem with less computational intensity and reflect the designer’s preference. The fundamental process of solving multi-objective optimization with PP is introduced firstly. And then, the optimization problem of glide reentry trajectory is established using PP method, in which four objectives: maximum range, minimum heat load, minimum peak value of heating rate and minimum oscillation are taken into account. A coneshaped winged reentry vehicle is taken as a numerical example. The preference structure is determined with analysis of the results of single-objective optimization. And the multiobjective optimal reentry trajectory is obtained by genetic algorithm. The constraints of heating rate, load factor and dynamic pressure are considered. The numerical results demonstrate the efficiency of the PP method. The physical causation of the optimal trajectory and the corresponding angleofattack profile are presented. It is a good reference for schematic trajectory design for gliding type reentry vehicles.

Key words: multi-objective trajectory optimization, physical programming, genetic algorithm, hypersonic vehicle, gliding reentry