Artemis II Leak Warning Nearly Scrapped Moon Burn 15 Minutes Before TLI

Q: What caused the terrifying false alarm that nearly aborted NASA's historic Artemis II lunar mission?

NASA has not publicly identified a specific hardware failure as the cause of the Artemis II cabin-leak warning; the alert was ultimately determined to be a false alarm in Orion’s monitoring system. What is clear from NASA’s account and astronaut Victor Glover’s remarks is that the warning appeared about 15 minutes before the critical translunar injection burn, forcing the crew and mission control to rapidly determine whether Orion had a real pressure leak or only a bad indication. NASA later cleared the spacecraft to continue, and Orion successfully completed the burn. The available reporting points to a sensor or instrumentation-related false indication rather than an actual cabin leak. The spacecraft was passing through a demanding environment near perigee, about 100 miles above Earth, where radiation levels were higher and the region was more crowded with satellites and debris. But neither NASA nor the crew has said publicly that radiation, debris, software, or any one component definitely triggered the alarm. So the short answer is that the terrifying alert was caused by a false cabin-leak warning from Orion’s onboard detection/monitoring system, but the precise technical root cause has not been publicly disclosed.

3 articles · Updated · Space.com · Oct 22

Victor Glover said Orion flashed a possible cabin-leak warning about 15 minutes before the translunar injection burn, creating a last-minute choice between pressing on to the moon or preparing to return to Earth.
The alert hit on April 2 as the spacecraft dropped to roughly 100 miles above Earth after a 38,000-mile loop, a phase Glover said was already complicated by denser orbital traffic and higher radiation.
NASA determined the warning was false, and Orion completed its main-engine burn in about 5 minutes 50 seconds, sending the crew toward the moon at roughly 24,500 mph.
The mission went on to set a new human-distance mark of 252,756 miles from Earth before the four astronauts splashed down safely on April 10 after nearly 10 days in space.