Core Viewpoint - The successful launch of the Shenzhou-21 manned spacecraft marks a significant advancement in China's space technology, particularly with the implementation of a 3.5-hour autonomous rapid rendezvous and docking process, showcasing innovation in space mission capabilities [1][2]. Group 1: Technological Innovations - The Shenzhou-21 mission challenges the previous docking time of 6.5 hours, aiming for a new record of 3.5 hours, which represents a major leap in space technology innovation [2]. - Key technological optimizations include reducing the number of orbits from three to two during the remote guidance phase, shortening the initial distance for close-range guidance, and unifying the optimization of the final stages of remote and close-range guidance [2]. - The GNC (Guidance, Navigation, and Control) system can switch between 3.5-hour and 6.5-hour docking modes, enhancing flexibility and safety during the mission [2][3]. Group 2: Mission Support Systems - The Long March 2F rocket underwent nearly 20 technical improvements to ensure precise orbital insertion, which is critical for the success of the 3.5-hour docking challenge [4]. - A robust measurement and control system, including global ground stations and space-based data relay satellites, ensures the spacecraft remains on course and connected during its mission [4]. - The docking mechanism developed by the China Aerospace Science and Technology Corporation is designed to absorb collision energy and achieve precise capture and locking during the final docking phase [4]. Group 3: Scientific Research Initiatives - The Shenzhou-21 mission is notable for being the first to conduct experiments with rodents in space, specifically four mice, to study their adaptation to microgravity [5][6]. - The primary goal of studying mice in space is to establish a comprehensive experimental system for mammalian space research, focusing on physiological and developmental responses to microgravity [6]. - Additional research includes in-situ studies of lithium-ion batteries in space, which will provide critical insights for future missions [6].

烈焰升腾，划破戈壁长空。10月31日23时44分，长二F火箭托举神舟二十一号载人飞船，将张陆、武 飞、张洪章3名航天员精准送入预定轨道，发射任务圆满成功。 挑战3.5小时快速交会对接 此次任务最引人瞩目的，无疑是神舟飞船首次在载人状态下挑战实施3.5小时自主快速交会对接。 此前，神舟八号与天宫一号空间实验站交会对接，用时两天；神舟十二号至神舟二十号，采用6.5小时 交会对接模式。如今，神舟二十一号挑战3.5小时交会对接，力争实现航天技术创新的又一次重大跨 越。 交会对接通常分为远程导引和近程导引两个阶段。负责导引的关键系统名为GNC（制导、导航与控 制），被称为飞船的"智慧大脑"。 从6.5小时到3.5小时，背后主要是3个层面的关键技术优化：一是远程导引段中，飞船绕地球飞行由3圈 减为2圈；二是缩短了近程导引段的初始距离，让飞船在更近的"起跑线"开始其最终的精准机动，压缩 最后一程的耗时；三是对远程导引的末段和近程导引的初段进行了统一优化，在可能存在目标轨道误差 过大的情况下也可以导引出正确轨迹，避免轨迹安全性问题。 专家表示，3.5小时交会对接，能够极大增强我国空间站任务规划的灵活性和应急响应能力。具体来 ...

Core Viewpoint - The successful launch of the Tianwen-2 probe marks the beginning of its mission to explore the asteroid 2016 HO3, which is considered a near-Earth satellite and holds significant scientific value for understanding the early solar system [1][2]. Group 1: Mission Objectives - The Tianwen-2 probe will take nearly a year to approach asteroid 2016 HO3, requiring multiple trajectory adjustments as it gets closer [2]. - The mission aims to gather detailed information about the asteroid's rotation axis, actual rotation period, size, shape, structure, surface conditions, and albedo [2]. - The probe will also identify suitable sampling points while avoiding adverse conditions that could affect the sampling process [2]. Group 2: Scientific Significance - Asteroid 2016 HO3 is considered a "living fossil" that retains primordial information from the early solar system, making it valuable for research on the composition, formation, and evolutionary history of the solar system [1]. - The proximity of the asteroid, located between 14 million to 40 million kilometers from Earth, allows for a lower energy requirement for the spacecraft to reach it [1]. Group 3: Technical Specifications - The Tianwen-2 probe weighs approximately 2.1 tons and has a wingspan of 15 meters, comparable to the weight of a small car and the length of a large bus [1]. - It is equipped with advanced scientific instruments, including a GNC system, to enhance its navigation capabilities in space [1].