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].

Group 1 - The Tianwen-2 mission is China's first asteroid sample return and main belt comet flyby mission, named as the second in the Tianwen series of planetary exploration tasks [3][5] - The mission aims to explore two small celestial bodies: asteroid 2016 HO3, known as a "quasi-satellite" of Earth, and main belt comet 311P, which has characteristics of both asteroids and traditional comets [7][9] - The exploration of small celestial bodies is significant as they contain primordial information about the solar system's formation and evolution, and can help identify potential threats to Earth [5][7] Group 2 - The Tianwen-2 mission will attempt innovative anchoring and touch sampling techniques, potentially making it the first spacecraft to use this technology on an asteroid [9]

Group 1 - The article discusses the evolution of asteroid exploration, highlighting the transition from telescopic observations to dedicated space missions [1][2] - The first close-up images of asteroids were captured by the Galileo spacecraft in 1991, marking a significant milestone in asteroid research [1] - The NEAR Shoemaker spacecraft became the first to land on an asteroid, specifically Eros, in 2001, providing detailed data on its physical and geological characteristics [1] Group 2 - Japan's Hayabusa spacecraft, launched in 2003, collected approximately 1,500 microscopic samples from the Itokawa asteroid, weighing about 0.0018 grams [2] - NASA's Dawn spacecraft explored both Vesta and Ceres, two distinct bodies in the asteroid belt, providing insights into their composition and evolution over nearly four years [2] - Various asteroid missions have employed different exploration methods, including flybys, landings, sample returns, and impact techniques, showcasing the advancements in space exploration technology [2]

Group 1 - The Tianwen-2 mission marks China's first interplanetary sample return mission, targeting asteroid 2016HO3 and comet 311P for scientific exploration and sample collection [1][2] - The mission aims to enhance understanding of the origins and evolution of small celestial bodies, with 2016HO3 potentially holding primordial information from the early solar system [2][3] - The Tianwen-2 spacecraft is equipped with 11 scientific payloads to study the morphology, composition, internal structure, and potential ejection materials of the targeted celestial bodies [2][3] Group 2 - The mission involves significant technical challenges, including long distances (2016HO3 is 18 to 46 million kilometers away, and 311P is 150 to 500 million kilometers away), which complicates communication and requires advanced orbital design and energy management [3] - The spacecraft must operate under weak gravitational conditions, making sample collection difficult, as the average diameter of 2016HO3 is approximately 41 meters and it is in a high-speed rotation [3][4] - The launch of the Long March 3B rocket required precise trajectory calculations, with a separation speed exceeding 11.2 kilometers per second and a deviation tolerance of less than 1 meter to ensure accurate orbital insertion [5]

Core Viewpoint - The Tianwen-2 mission represents China's first attempt to conduct asteroid sample return and flyby exploration of a main belt comet, with a planned launch by the end of May 2023 [1][3]. Group 1: Mission Objectives - The Tianwen-2 mission aims to explore asteroid 2016HO3, which is the first known quasi-satellite of Earth, with a diameter of approximately 40-100 meters and a rotation period of about 28 minutes [3][5]. - The mission will also investigate main belt comet 311P, which has an average diameter of about 480 meters and an orbital period of approximately 3.24 years [6][8]. - The mission's scientific goals include determining the physical parameters of both celestial bodies, such as orbital and rotational characteristics, surface composition, and internal structure [10][11]. Group 2: Scientific Significance - Asteroid 2016HO3 is considered a "living fossil" that retains primordial information about the early solar system, making it valuable for studying the composition and evolution of solar system materials [5][10]. - The analysis of samples returned from 2016HO3 will provide insights into the origins and evolution of asteroids, as well as the early solar system's formation processes [11][13]. - The exploration of 311P aims to address scientific questions regarding the nature of main belt comets and their formation, potentially reshaping current understanding of these celestial bodies [11][12]. Group 3: Future Plans - The Tianwen-2 mission is part of a broader Chinese planetary exploration program that includes future missions to Mars and the Jupiter system, with plans for Tianwen-3 and Tianwen-4 to achieve Mars sample return and Jupiter exploration, respectively [12][14]. - The mission is expected to enhance China's position in international space exploration activities, particularly in the field of asteroid defense and resource utilization [13][14].