Fuel Leak Delays Artemis II Moon Mission

​NASA has postponed the upcoming Artemis II Moon mission launch after engineers detected hydrogen fuel leaks during a full wet dress rehearsal fueling test of the Space Launch System (SLS) rocket.
 
During a recent countdown rehearsal at Kennedy Space Center, teams noticed a leak in the liquid hydrogen system used to load super‑cold propellant into the rocket’s core stage. The leak came from an interface used to route cryogenic fuel into the core stage, forcing multiple pauses in fueling and eventually an early end to the test. NASA reported that the leak worsened near the end of the rehearsal, leading controllers to stop the test with only a few minutes left in the planned countdown. Liquid hydrogen must be kept extremely cold and is loaded through long, complex plumbing; even small seal or fitting issues can create significant leaks that pose safety and performance risks. Similar hydrogen leak problems delayed earlier SLS tests, and the uncrewed Artemis I mission, so NASA is emphasizing thorough testing before flying astronauts.
 
The crewed Artemis II mission, originally targeting a February launch, is now delayed until at least March to give engineers time to review data, repair seals or components if needed, and run another fueling test. The four astronauts assigned to the lunar fly‑by have been released from their pre‑launch quarantine and will re‑enter quarantine roughly two weeks before the next launch window.
 
NASA plans to inspect the leaking interface, perform any necessary pad-side repairs if possible, and conduct another wet dress rehearsal to confirm leak‑free fueling before attempting the March launch. Managers stress they will only proceed with the crewed Moon fly‑by once they are confident the rocket’s fueling system is operating safely and reliably.
 
Reference
Associated Press. (2026, February 3). NASA Delays Astronauts’ Lunar Trip Until March After Hydrogen Leaks Mar Fueling Test. US News.
 
Desmarais, A. (2025, February 3). Artemis II Moon Mission Launch Delayed Again to March Due to Fuel Leak, NASA Says. Euro News.
 
Malik, T. (2022, September 4). Fuel Leak Delays NASA’s Artemis 1 Moon Mission Launch. Space.Com.
 
Reuters. (2026, February 3). NASA Delays Artemis 2 Moon Mission to March Due to Liquid Hydrogen Leak. Reuters.