This paper analyzes the flight trajectory of the launch vehicle which burns solid propellant. First, the maximum payload which the launcher can transport to the target orbit must be evaluated. This problem is solved by not directly calculating the max. payload but using the indirect subploblem which optimizes the quantity related to payload. We use this indirect method so as to strengthen the convergence and stability of program. So, the payload maximization problem is one of trajectory optimization's. Two numerical methods for obtaining the trajectory are considered. One is 'optimal control theory', the other is 'nonlinear programming method'. The former presents optimal solution, the latter does suboptimal one. But the latter makes use of very simple pitch program, and it is more practical.
Then, loaded with the max. payload, the launcher takes a flight along the precalculated path. But many factors which were not considered in optimization problem may affect the vehicle to digress from the nominal trajectory. In this case the control must be corrected for the vehicle to accomplish the mission. With large pertubation of states, the vehicle may not be controllable, but controllability region is treated in some ways.