Following a failed attempt earlier this week, NASA has once again delayed the start of its Artemis 1 Moon mission. The agency was forced to scrub Saturday’s launch after staff at Kennedy Space Center failed to fix a persistent leak in a liquid hydrogen connection point on the agency’s next-generation Space Launch System super heavy-lift rocket. 

NASA detected the leak at 7:23AM ET and tried to troubleshoot the problem in a few different ways, but after three failed attempts ground crew recommended a “no go” for Saturday’s launch attempt. Monday’s attempt was cut short after one of the four on the SLS could not reach the appropriate temperature to send Artemis 1 into space.    

“The Artemis I mission to the Moon has been postponed. Teams attempted to fix an issue related to a leak in the hardware transferring fuel into the rocket, but were unsuccessful,” NASA said on Twitter. 

Provided NASA can fix the leak on Launch Pad 39B, the agency has one last window it can attempt a launch before a major delay becomes inevitable. If it can’t fly by September 5th, NASA will need to roll the SLS back to the Kennedy Space Center’s Vehicle Assembly Building to conduct a test of the rocket’s flight termination system. At that point, the earliest Artemis 1 could get underway would be September 19th, but an October launch would be more likely.