AHTHGC(SZ:000901) Xin Jing Bao·2025-11-01 00:14Core Viewpoint - The successful docking of the Shenzhou 21 manned spacecraft with the Chinese space station in 3.5 hours marks a significant breakthrough in China's manned spaceflight technology, showcasing advancements in autonomous rapid rendezvous and docking capabilities [1][5]. Group 1: Technological Evolution - The 3.5-hour rendezvous mode represents a "V2.1 version" of China's docking technology, building on the previous V2.0 framework that reduced docking time from approximately 2 days to 6.5 hours [2]. - The Shenzhou 21 mission utilized a mature autonomous navigation and trajectory control framework, adapting the 3.5-hour docking experience from the Tianzhou 7 cargo spacecraft, which allows for more relaxed system requirements compared to the 2-hour plan of Tianzhou 5 [2][4]. Group 2: Autonomous Control - The docking process consists of two phases: the remote guidance phase and the close-range guidance phase, both of which have been fully autonomously controlled by China [3]. - The remote guidance phase involves the spacecraft adjusting its orbit to approach the space station, while the close-range phase focuses on precise adjustments to ensure accurate docking [3]. Group 3: Technical Optimizations - The reduction of docking time from 6.5 hours to 3.5 hours is attributed to three key technical optimizations: 1. More precise launch and orbital control to minimize initial phase differences, allowing for fewer orbital adjustments [4]. 2. Shortening the initial distance in the close-range guidance phase to start the final maneuvers closer to the docking point [4]. 3. Unified optimization of flight trajectories to enhance system fault tolerance and adaptability, ensuring safe approaches even with potential orbital discrepancies [4]. Group 4: Operational Flexibility - The guidance, navigation, and control (GNC) system can switch between the 3.5-hour and 6.5-hour docking modes based on real-time assessments of the spacecraft's status, providing operational flexibility [5]. - The significant reduction in docking time enhances the feasibility of mission planning and execution, particularly in critical situations, ensuring astronaut safety and mission success [5].