瞭望 | 天问二号叩响中国小行星探测之门

Core Viewpoint - The Tianwen-2 mission aims to explore and sample asteroid 2016HO3 and subsequently conduct scientific exploration of main-belt comet 311P, marking China's first attempt at asteroid sample return and advancing deep space exploration [1][2][13]. Mission Overview - The Tianwen-2 mission is led by the National Space Administration of China, with a long and challenging implementation cycle of approximately 10 years, facing significant engineering risks and uncertainties [2][13]. - The mission consists of 13 flight phases, including launch, asteroid transfer, close approach, sampling, and return segments [13]. Launch Details - The Long March 3B rocket, known for its high payload capacity, successfully launched the Tianwen-2 spacecraft from the Xichang Satellite Launch Center on May 29, 2025 [1][4]. - This mission is the first time the Long March 3B rocket has executed a launch to escape Earth's gravitational pull, requiring a speed of at least 11.2 km/s [5][6]. Challenges Faced - The launch faced three main challenges: higher speed requirements, increased precision demands, and a narrower launch window [6][9]. - The launch window for the mission was limited to three days, with only four minutes available each day for a successful launch [9]. Technical Innovations - The mission has implemented various technical improvements, including enhanced payload capacity and precision tracking systems, to ensure successful launch and mission execution [10][11]. - The spacecraft is equipped with 11 scientific instruments for spectral measurement, optical imaging, and environmental detection, aimed at gathering valuable data during its journey [13][16]. Scientific Goals - The scientific objectives focus on determining the physical parameters of the asteroid and comet, including their orbital dynamics, composition, and internal structure [17]. - The mission aims to contribute to the understanding of the early solar system and the formation of celestial bodies, with particular emphasis on the unique characteristics of the target asteroid and comet [16][17].