揭秘中国首次小行星探测与采样返回：探什么？怎么去？有何难？

Group 1 - The core viewpoint of the article highlights China's successful launch of the Tianwen-2 probe, marking the country's first asteroid sampling and return mission, following the Tianwen-1 Mars exploration mission [1][3] - The Tianwen-2 mission aims to achieve multiple objectives, including the exploration and sampling of asteroid 2016HO3 and subsequent scientific investigation of main-belt comet 311P, with a focus on key technological breakthroughs and providing valuable data for research on asteroid origins and evolution [4][6] - The mission involves a complex flight process with 13 stages over approximately 10 years, including phases for approaching, detecting, and sampling the asteroid, followed by a return phase expected to conclude with landing on Earth by the end of 2027 [5][6] Group 2 - The Tianwen-2 mission presents new technical challenges compared to previous missions, as scientists face uncertainties regarding the rotation speed and surface conditions of asteroid 2016HO3, necessitating a "fly, explore, and decide" strategy [6][7] - The mission's complexity is further compounded by the weak gravitational conditions of the asteroid, which has an average diameter of about 41 meters, requiring the probe to achieve stable attachment and sampling under high-speed rotation and low gravity [6][7] - The long-distance nature of the mission, with asteroid 2016HO3 located between 18 million to 46 million kilometers from Earth and main-belt comet 311P between 150 million to 500 million kilometers away, imposes high demands on orbital design, energy management, and the probe's longevity and reliability [7]