我国神舟飞船首次实施3圈快速返回

Core Points - The Shenzhou-21 manned spacecraft successfully completed its return mission, marking a breakthrough in China's re-entry and return technology with enhanced system reliability [1] - The re-entry and return process involves the spacecraft leaving orbit, entering the Earth's atmosphere, and landing safely, with the GNC system being crucial for flight control [1] - The Shenzhou program has evolved through two generations of re-entry technology, with the latest Shenzhou-21 utilizing a new three-orbit autonomous quick return strategy [2] Group 1 - The Shenzhou-21 spacecraft implemented a three-orbit autonomous quick return, improving upon the previous five-orbit method, which reduces the return time by over three hours [2] - The transition from ground-based to onboard computation for deorbit control parameters represents a significant advancement in the spacecraft's autonomous capabilities [2] - The GNC system, developed by the 502nd Institute, plays a critical role in ensuring the accuracy and reliability of the spacecraft's return process [1][2] Group 2 - The development of re-entry technology in China's manned space program has progressed from standard ballistic adaptive guidance to adaptive predictive guidance, culminating in the current autonomous quick return method [3] - The ongoing efforts by the 502nd Institute aim to strengthen key core technologies and achieve new heights in manned spaceflight technology [3]