NASA’s Artemis moon mission faces new issue after test shows reduced hydrogen flow

NASA’s long-awaited return to the Moon has faced another technical challenge. During a recent test of its Artemis II mission, engineers detected a reduced flow of liquid hydrogen while preparing the rocket for a key rehearsal ahead of the crewed lunar fly-by.

The issue emerged during a ground test aimed at checking newly replaced seals in the rocket’s hydrogen system. While several test goals were met, the lower-than-expected hydrogen flow added another complication to a programme already under pressure.

What went wrong during the latest Artemis test

According to NASA, the problem appeared when teams tried to partially fill the liquid hydrogen tank of the Space Launch System. The test was meant to confirm that new seals could prevent leaks that disrupted earlier rehearsals.

Engineers later traced the reduced flow to ground support equipment, not the rocket itself. A clogged filter is now the main suspect. NASA said teams will clean the affected lines and replace the filter before deciding when to attempt the next full wet dress rehearsal.

Despite the issue, NASA confirmed that valuable data was collected from the same areas where hydrogen leaks were seen in the past.

Why hydrogen leaks matter for Artemis II

Liquid hydrogen is a critical fuel for the Space Launch System. Even small issues can force delays because hydrogen is difficult to handle safely.

NASA has spent nearly three years fixing leak problems first seen during early tests in 2022. However, similar issues resurfaced earlier this month, raising concerns about whether the system is finally stable.

Data from the latest test will help engineers decide if the hydrogen problem has been fully understood or if further fixes are needed before launch.

Artemis II

The Artemis II mission will carry four astronauts Reid Wiseman, Victor Glover, Christina Koch and Jeremy Hansen on a journey around the Moon. It will be the first crewed mission beyond Earth orbit since the Apollo era ended in 1972.

During the mission, the Orion spacecraft will fly past the Moon’s far side, a region never seen directly by humans. Astronauts will observe lunar craters, lava plains and surface features, sending images and data back to Earth to support future Moon landings.

NASA says these observations are vital for preparing later missions to the Moon’s south pole.

Launch timeline

NASA has said March remains the earliest possible launch window for Artemis II, with five potential dates between March 6 and March 11. If those dates are missed, the mission could be pushed to April.