For the first time since Apollo 17 in 1972, the crewed test flight to send humans into lunar orbit, Artemis II, has gone back into checks ahead of launch.
The National Aeronautics and Space Administration (NASA) said on the 22nd (local time) that it plans to roll the Space Launch System (SLS) rocket and the Orion spacecraft off Launch Pad 39B at Florida's Kennedy Space Center and return them to the Vehicle Assembly Building.
The issue emerged after the wet dress rehearsal (WDR), which recreated the launch procedures as in reality. The helium system operated normally during the rehearsal, but signs of abnormal helium flow were detected while reconfiguring equipment after the test ended, according to reports. Candidates for the cause include the ground facility and the rocket interface, an upper-stage valve, and a filter between the ground and the rocket. The helium system keeps the upper-stage engine environment stable and manages the internal pressure of the liquid hydrogen and liquid oxygen propellant tanks.
Once the launch vehicle returns to the Vehicle Assembly Building, a March launch—initially under consideration—appears unlikely. NASA said, however, that because it decided to roll back early, if inspections and repairs are completed quickly, an April launch remains possible.
Artemis II is a mission in which four astronauts will fly in lunar orbit for about 10 days to check navigation maneuvers that use the moon's gravity, among other objectives. NASA plans to pursue a lunar landing in subsequent phases after this mission.
Meanwhile, the mission will also carry the small satellite K-RadCube, developed by the Korea Astronomy and Space Science Institute (KASI). After launch, K-RadCube will separate at an altitude of about 70,000 kilometers and enter its own orbit, then pass through Earth's radiation belts, the Van Allen belts, to measure space radiation intensity.