Abstract: The rover transfer mechanism is a space mechanism that transfers and releases the rover in the extraterrestrial space environment. Different from the former transfer tasks of the United States and the Soviet Union, in the second phase of the China's Lunar Exploration Project (CLEP), the landing-leg buffer mechanism is used for the lander of the incorporates spacecraft and the rover is mounted on top of the lander. The transfer distance of the rover along the circumferential direction of the lander and the release height of the rover dramatically increase the difficulty of the transfer task. The keys to the completion of the exploration mission include the transfer mechanism meeting the strict engineering constraints and design indexes of the mission in the design phase and high reliability of transferring the rover in the uncertain lunar surface environment in the execution phase. This paper provides the research and design processes of the Chang'e transfer mechanism in the second stage mission of the CLEP. Based on the characteristics of the rover transfer system of the Chang'e probe, the compositions, requirements, and constraints of the design are introduced. In addition, drawing on the experience of the participants, the proposal selections, key design points, engineering status, and verifications of the transfer mechanism are described, providing reference and support for associated projects in the following Lunar and Mars exploration missions.

Key words: Lunar Exploration Phase II, Chang'e-3, Chang'e-4, transfer mechanism, mechanism design, mission verification