The Artemis 1 rocket fueling test hit another snag on Wednesday morning after a leak like the ones that had delayed previous launch attempts.
NASA said its mission managers had detected a liquid hydrogen leak at the eight-inch quick disconnect seal between the tail service mast umbilical and the rocket.
The launch director signed off on a plan to warm up the line to try and reset the connection point.
Then, the flow of liquid hydrogen into the core stage resumed in the fast-fill stage.
NASA completed the engine kickstart bleed test on the rocket's main engines.
The agency said, more than five hours into the cryogenic demonstration test and after the core stage liquid oxygen was in replenish, that the hydrogen leak remained manageable during the test.
"Core stage liquid hydrogen fast fill is now complete and we are in replenish. The hydrogen leak is holding at 0.5%," NASA Exploration Ground Systems tweeted.
"Teams warmed up the quick disconnect umbilical line and the leak then maxed out at 3.4%, which is within the acceptable range to continue," the team said.
Teams were pressing ahead with operations to load propellants into the interim cryogenic propulsion stage of the rocket.
After the liquid hydrogen and liquid oxygen loading on the stage reached the replenish phase, the pre-press test was slated to occur.
"The pre-pressurization test will bring the core stage liquid hydrogen tank up to the pressure level it will experience just before launch while engineers calibrate the settings for conditioning the engines at a higher flow rate, as will be done during the terminal count on launch day," NASA said in a blog post.
The upper stage of the Space Launch System was loading minutes later, according to NASA spokesperson Derrol Nail.
The "wet dress rehearsal" is a critical step to ensure the rocket is ready for its test flight.