US manned lunar mission training exercise suffers liquid hydrogen leakage; launch postponed until March

On Monday (February 2nd), NASA conducted a comprehensive rehearsal for the "Artemis 2" manned lunar orbit mission, covering key aspects such as propellant refueling and launch countdown. However, due to a liquid hydrogen leak at the propulsion interface of the rocket's core stage, the countdown was halted.

Xinhua News Agency reported that NASA has announced that the launch window for the mission will be postponed from February to March.

The content of this drill included filling the new-generation lunar launch vehicle "Space Launch System" with cryogenic liquid hydrogen, and conducting a rehearsal of the launch countdown procedure. During the drill, a leak of liquid hydrogen occurred at the propellant interface of the rocket's core stage, requiring multiple pauses in operations to take countermeasures, such as adjusting the propellant flow rate, which caused the countdown process to be delayed.

In addition, the pressure valve of the "Orion" crew module needs to be re-tightened after recent replacement, and the operation takes a long time. Moreover, there were issues such as the impact of low temperatures on some cameras and equipment, and intermittent interruptions in audio communication between the ground team. When the countdown test was 5 minutes and 15 seconds remaining, due to a sudden increase in the leakage rate of liquid hydrogen, the relevant equipment automatically stopped the countdown.

The US aerospace agency stated that the comprehensive drill was designed to identify and resolve potential issues, ensuring the smooth progress of the launch mission. The relevant team will thoroughly review the test data, address the problems encountered during the drill, and conduct another round of comprehensive drill tests before determining the official launch date.

The head of NASA's aerospace agency, Isaacman, said, "The Space Launch System has been in development for over three years since its last launch. Challenges are to be expected. This is precisely the reason for conducting comprehensive test drills. After the drills, the team decided to abandon the launch window in February and set the target for March."

In 2019, the United States announced the "Artemis" lunar landing program and completed the unmanned lunar orbiting test mission of "Artemis 1" in November 2022. According to the plan, in the "Artemis 2" manned lunar orbiting mission, four astronauts will board the "Orion" spacecraft for a lunar orbiting flight lasting approximately 10 days. The relevant astronauts did not participate in this comprehensive drill. After the completion of the "Artemis 2" mission, the US space agency will promote the implementation of the "Artemis 3" manned lunar landing mission.