GNC system scheme for lunar soft landing spacecraft

A pinpoint autonomous GNC system scheme for lunar soft landing is proposed. First, the descriptions of the mission outline for lunar soft landing are provided. Second, the GNC system design of the spacecraft is proposed. The baseline is a 3-axis stabilized system during all the phases of the mission. Orbit maneuvers are achieved by an assembled constant thrust or a throttleable main engine. The attitude control actuators are thrusters. The attitude and orbit determination is performed by sun sensors, star sensors, Inertial Measurement Unit (IMU), altimeter, velocimeter and lunar imaging sensors. Third, some proposed autonomous navigation and guidance methods including hazard detection and avoidance for lunar soft landing are analyzed. Finally, we draw some conclusions.