Impact Response Control Mechanism Composed of Two Kinds of Springs with Contraction Lock Mechanism and Its Application to Celestial Landing Exploration

Abstract

Spacecraft landing gear employed in space missions is required to achieve secure touchdown on rough and inclined terrains. Generally, when a spacecraft performs a free fall from a certain altitude, its landing gear needs to absorb the impact of touchdown. Conventional landing gear, such as the honeycomb crush absorber, absorbs the impact of landing through plastic deformation of its structure. However, such landing gear cannot effectively prevent the spacecraft from tipping over, and the non-reusability of such landing gear often leads to an increase in experimental costs. To address these issues, this paper proposes a novel landing gear mechanism that comprises a contraction lock mechanism with multiple springs for enhancing reusability. The proposed mechanism varies the spring constant by operating the contraction lock mechanism according to the touchdown response, and thus potentially prevents the spacecraft from tipping over. The effectiveness of the proposed mechanism in the case of inclined terrains is verified through conducted simulations. Furthermore, the performance of the proposed mechanism is compared with that of the conventional plastic deformation shock absorber in terms of adaptability to variations in the spacecraft's initial velocity and initial attitude angle. The obtained results show that the proposed mechanism can be effective in executing secure landings on inclined terrains.