NASA Delays Artemis II Moon Mission to March After Hydrogen Leak Detected During Rehearsal
Dress rehearsal halted in final minutes after leak found in Space Launch System rocket; communication issues also flagged
The leak was discovered in the final five minutes of the full wet dress rehearsal, where engineers fill the Space Launch System rocket with liquid hydrogen and oxygen to simulate launch conditions. Communication issues with the Orion crew capsule were also identified during testing.
NASA Administrator Jared Isaacman said on X that the tests "are designed to surface issues before flight and set up launch day with the highest probability of success," adding that an additional wet dress rehearsal will be conducted before targeting the March launch window.
Hydrogen leaks have been a recurring challenge for the Artemis program. The first uncrewed Artemis I mission in 2022 was scrubbed twice — once for a faulty engine temperature reading and once for a hydrogen leak during fuelling — ultimately launching three months after the initial attempt.
The four-person crew — commander Reid Wiseman, pilot Victor Glover, and mission specialists Christina Koch and Jeremy Hansen — will be the first humans to travel to the Moon in more than 50 years. The 10-day mission will take them beyond the far side of the Moon, potentially farther from Earth than any human has ever travelled.
NASA had identified three launch windows: early February, early March, and late March through April. With the February window now closed, the agency is targeting March 6-11 as the next opportunity, with backup dates available through late April.
Analysis
Why This Matters
Artemis II represents a critical stepping stone toward returning humans to the lunar surface under Artemis III. Any delay cascades through the broader program timeline and tests public and political patience with NASA''s most ambitious crewed exploration program in decades.
Background
The Space Launch System is the most powerful rocket NASA has ever built. The Orion capsule was successfully tested uncrewed during Artemis I in 2022, completing a 25-day mission around the Moon. Hydrogen''s tiny molecular size makes it notoriously difficult to contain, a challenge engineers have grappled with across multiple launch systems.
Key Perspectives
Space systems engineer Robert Howie from Curtin University noted that hydrogen leaks are "a common problem" given the molecule''s tendency to escape seals. Gilmour Space Technologies CEO Adam Gilmour said delays are routine in spaceflight: "There''s a whole lot of things that have to work."
What to Watch
Whether the next wet dress rehearsal resolves both the hydrogen leak and communication issues will determine if NASA can hit the March window or faces further delays into April.