Tentative Solutions for Indirect Optimization of Spacecraft Trajectories

In this chapter, the problem of improving convergence and finding suitable tentative solutions for the indirect optimization of spacecraft trajectories is discussed. The application of theory of optimal control to spacecraft trajectories transforms the optimal control problem into a multi-point boundary value problem, which is usually solved by means of an iterative procedure. The convergence radius of the problem may be small and convergence to the optimal solution is only obtained if the tentative solution, which is used to start the procedure, is sufficiently close to the optimum. The definition of a suitable solution is often the hardest part of the solution procedure for the optimization problem. Several cases and examples are presented in this chapter to illustrate the measures that could be adopted for the most common difficulties, which may be found during the optimization of space trajectories.