Abstract
Execution of scientific objectives such as to investigate the central peaks of a big crater of the moon is thought to be the most scientifically interesting. Precise and safe autonomous landing ability is a productive issue for this investigation. Here it is proposed a scheme of trajectory generation for lunar descent. This research includes a sketch of a qualitative scheme on solutions of motion control equations for lunar descent vehicle from orbital speed condition down to the terminal descent situation. A trajectory generation algorithm is developed accumulating more than one step with variable thrust to mass ratio. Mathematical modeling, algorithm design, simulations and results are presented in this paper. In fact, the proposed trajectory generation scheme can readily be used to develop real-time guidance algorithm for future precise and safe lunar landing missions reducing the computational burden.