我国载人飞船首次实施三圈自主快速返回

Core Viewpoint - The successful landing of the Shenzhou-21 manned spacecraft marks a significant advancement in China's re-entry and return technology, achieving a new level of system reliability with a reduced return time of over 3 hours compared to previous missions [1] Group 1: Re-entry Control - The Shenzhou series spacecraft are developed by the China Aerospace Science and Technology Corporation, with the GNC system acting as the "intelligent driver" responsible for flight control from launch to re-entry [2] - Re-entry control involves two main aspects: orbital departure control and atmospheric re-entry control, with the latter focusing on lift control within the atmosphere [2] Group 2: Transition from 5 Orbits to 3 Orbits - The shift from a 5-orbit to a 3-orbit return strategy enhances the efficiency and emergency response capability of the Shenzhou spacecraft, with onboard computers now autonomously calculating departure control parameters [3] - Multiple verification processes were conducted to ensure the accuracy of the autonomous calculations, confirming the spacecraft's ability to return to Earth with high precision [3] Group 3: Significance of 3-Orbit Autonomous Quick Return - The implementation of the 3-orbit autonomous quick return significantly improves the spacecraft's ability to handle major faults during autonomous flight and docking phases [4] - The reduction in return time from the space station to Earth demonstrates the stability and reliability of China's re-entry technology, showcasing over 30 years of development in this field [4]