Research on the Encapsulation Device for Lunar Samples

Abstract

The encapsulation of lunar samples is a core research area in the third phase of the Chinese Lunar Exploration Program. The seal assembly, opening and closing mechanism (OCM), and locking mechanism are the core components of the encapsulation device of the lunar samples, and the requirements of a tight seal, lightweight, and low power make the design of these core components difficult. In this study, a combined sealing assembly, OCM, and locking mechanism were investigated for the device. The sealing architecture consists of rubber and an Ag-In alloy, and a theory was built to analyze the seal. Experiments of the electroplate Au coating on the knife-edge revealed that the hermetic seal can be significantly improved. The driving principle for coaxial double-helical pairs was investigated and used to design the OCM. Moreover, a locking mechanism was created using an electric initiating explosive device with orifice damping. By optimizing the design, the output parameters were adjusted to meet the requirements of the lunar explorer. The experimental results showed that the helium leak rate of the test pieces were not more than 5 × 10−11 Pa·m3·s−1, the minimum power of the OCM was 0.3 W, and the total weight of the principle prototype was 2.9 kg. The explosive driven locking mechanism has low impact. This investigation solved the difficulties in achieving tight seal, light weight, and low power for the lunar explorer, and the results can also be used to explore other extraterrestrial objects in the future.