美载人绕月飞行任务综合演练中止，发射推迟至3月

Group 1 - NASA conducted a comprehensive rehearsal for the "Artemis 2" crewed lunar flyby mission, which included key elements such as propellant loading and launch countdown procedures. However, the countdown was halted due to a liquid hydrogen leak at the rocket's core stage propellant interface, leading to a delay in the launch window from February to March [1][2] - The rehearsal involved loading cryogenic liquid hydrogen into the new generation lunar rocket, the Space Launch System (SLS), and practicing the countdown procedures. The liquid hydrogen leak required multiple pauses in operations to implement countermeasures, such as adjusting propellant flow, which delayed the countdown process [1] - NASA Administrator Bill Nelson acknowledged that challenges were expected given that it has been over three years since the last launch of the Space Launch System, emphasizing the importance of conducting comprehensive rehearsal tests to identify and resolve potential issues [1] Group 2 - The "Artemis" lunar program was announced by the U.S. in 2019, with the "Artemis 1" unmanned lunar flyby test completed in November 2022. The "Artemis 2" mission will involve four astronauts aboard the Orion spacecraft for approximately 10 days of lunar flight, although these astronauts did not participate in the recent rehearsal [2] - Following the completion of the "Artemis 2" mission, NASA plans to advance the implementation of the "Artemis 3" crewed lunar landing mission [2]