Core Points - The article discusses the composition and roles of astronauts in China's space missions, particularly focusing on the Shenzhou 21 mission, which includes three types of astronauts: pilot, flight engineer, and payload specialist [1][6][7]. Group 1: Astronaut Roles and Responsibilities - The Shenzhou 21 crew consists of Zhang Lu as the pilot, Wu Fei as the flight engineer, and Zhang Hongzhang as the payload specialist [7]. - Wu Fei's responsibilities include system maintenance, threat management, and new technology validation for the space station [9]. - Zhang Hongzhang aims to enhance research efficiency in the space station and is involved in various scientific experiments [14][57]. Group 2: Mission Objectives and Scientific Research - The Shenzhou 21 mission will conduct its first mammal space experiment, marking a significant step in China's life sciences research [25]. - The crew will engage in over a hundred scientific experiments across various fields, including microgravity physics and space medicine [57][66]. - Zhang Hongzhang plans to focus on energy storage research, particularly high-energy lithium-ion batteries, during the mission [55][66]. Group 3: Training and Preparation - Zhang Lu emphasizes the importance of rigorous training and teamwork among astronauts of different generations to ensure mission success [26][28]. - Wu Fei reflects on the challenges faced during astronaut selection and training, highlighting the need for perseverance and dedication [44][47]. - Zhang Hongzhang has undergone extensive physical training to prepare for the demands of space travel, improving his fitness significantly [64].