The key technologies for radial rib deployable antenna of Chang’e-4 relay satellite

The radial rib deployable antenna is critical for Chang’e-4 relay satellite. The antenna can be stowed for launch and precisely deploy on the orbit. The deployment of the mechanism, the on-orbit stability of surface accuracy and the validation under the extreme low temperature are the keys for the success of relay satellite. The distributed spring-driven mechanism for the antenna is firstly proposed in this paper. The spring is released slowly in the deployment. The mechanism is verified in the high and low temperature. Secondly, the material and structure of the antenna are optimised for the high stability of surface accuracy. The surface accuracy of the antenna is analysed under extreme conditions. The maximum thermal distortion is far superior to the requirement. The extremely low-temperature experiments are finally designed for validating the capability of antenna based on the simulation of on-orbit environment. The results show the performance of the antenna is unvarying under the extreme low temperature. The radial rib deployable antenna can satisfy all the requirements on orbit and guarantee the success of the relay mission of Chang’e-4 satellite.