Computer simulation methods for launch vehicle mission and control problems

Abstract

The flight control system of a launch vehicle is the result of the right trade-off between different objectives, such as the interaction between the control, guidance and performance aspects of a mission with specified end conditions and the analysis of the mission trajectories and vehicle systems under a variety of normal and failure modes. Hence an evaluation of the design and performance of such a system is not feasible through purely analytical means even with simplified models. This, together with the necessity for step-by-step refinement of the models used for the vehicle and its environment, calls for the computer simulation approach. The various considerations involved in developing and selecting the simulation model and implementing it on a computer are discussed. To illustrate the approach, a hybrid simulation evaluation of the performance of the first stage control system of a satellite launch vehicle and that of the controlled vehicle under different operational modes is presented.