Design of a deployable aerodynamic decelerator based on a tensegrity structure

Deployable aerodynamic decelerators are more suitable for planetary exploration missions than rigid aerodynamic decelerators. Their sizes are less limited by the launch vehicle shroud, allowing heavier payloads to be delivered to the surfaces of planets. Aiming at the problem of lightweight designs in deployable aerodynamic decelerators, a deployable tensegrity structure composed of two frustum tensegrity units and a prism tensegrity unit is proposed. To design the deployable tensegrity structure, a self-equilibrium model that is especially suitable for the structure with rotational symmetry is established according to prestressability conditions and force equilibrium equations. Based on the deployable tensegrity structure, the deployment mechanism, with the action of drive units, is designed to realize the transformation from the stowed state to the deployed state of the decelerator. The tensegrity structure always has rotational symmetry to make the deployment process highly synchronized due to the fact that drive units can work simultaneously. During the deployment process, the transverse distance and longitudinal distance are used to measure the deployment degree of the tensegrity structure. The types of axial forces for members are used to determine whether the tensegrity structure is stable. The result shows that the deployment process has continuity and that the tensegrity structure always stays stable.