首次小行星探测与采样返回之旅 “金牌老将”长三乙跑好第一棒

Core Viewpoint - The successful launch of the Tianwen-2 probe marks China's first mission to explore and sample an asteroid, advancing deep space exploration efforts [1][3]. Group 1: Mission Overview - The Tianwen-2 probe was launched on May 29, 2023, at 1:31 AM using the Long March 3B rocket, entering a transfer orbit to the asteroid 2016 HO3 after approximately 18 minutes of flight [3]. - The primary objectives of the Tianwen-2 mission include exploring the asteroid 2016 HO3, collecting samples, and returning them to Earth, with an expected landing date by the end of 2027 [3]. - Following the asteroid mission, the probe will conduct scientific exploration of the main belt comet 311P, which is located between the orbits of Mars and Jupiter [3]. Group 2: Technical Aspects of the Launch - The Long March 3B rocket, known as China's "gold medal rocket," has a high reliability rate and is primarily used for launching high-orbit spacecraft [4]. - This launch marks the 109th mission for the Long March 3B rocket, which has previously successfully launched various satellites, including the Chang'e lunar probes [6]. - The rocket's trajectory design and system optimizations were crucial for ensuring the success of the Tianwen-2 mission, with the launch team overcoming numerous challenges to achieve this high-density launch schedule [6][9]. Group 3: Precision and Challenges - The mission to the asteroid requires extremely high precision in orbital insertion, with a deviation limit of no more than 1 meter per second [7]. - The rocket's insertion speed needed to reach 11.2 kilometers per second, comparable to making a basketball shot from Shanghai to a hoop in Beijing, while ensuring the correct angle and speed upon entry [9]. - The design workload for this mission was three times greater than that of conventional launches, necessitating two years of iterative optimization by the rocket development team [9].