Abstract:In order to study the impact of variable engine thrust on rocket ballistic performance, the optimization and analysis of rocket trajectory based on variable thrust engine is carried out by using the Gaussian pseudo-spectrum method, including trajectory comparison analysis under variable thrust and fixed thrust, and the influence of thrust adjustment ability on trajectory and trajectory comparison analysis based on variable thrust engine under different optimization objectives. The results show that if the specific impulse is unchanged and engineering constraints are not considered, the thrust adjustment ability of the engine will make the trajectory of the rocket more flexible, and the speed and height coverage of the flight end will be increased, and the normal overload of the flight will be reduced. In addition, the greater the engine’s ability to regulate thrust, the more adaptable a rocket’s active segment trajectory is.