After a recurrence of one of the two problems which saw the first Artemis I launch scrubbed - a hydrodgen leak on an umilical quick disconnect - the second was also scrubbed.

NASA made three attempts to fix the problem during launch but ultimately called it off and ruled out any further launch attempts in early September.

Following the first failed launch attempt NASA said:

Mission managers met Tuesday to discuss data and develop a forward plan to address issues that arose during an Aug. 29 launch attempt for the flight test. During that launch attempt, teams were not able to chill down the four RS-25 engines to approximately minus 420 degrees F, with engine 3 showing higher temperatures than the other engines. Teams also saw a hydrogen leak on a component of the tail service mast umbilical quick disconnect, called the purge can, and managed the leak by manually adjusting propellant flow rates.

In the coming days, teams will modify and practice propellant loading procedures to follow a procedure similar to what was successfully performed during the Green Run at NASA’s Stennis Space Center in Mississippi. The updated procedures would perform the chilldown test of the engines, also called the kick start bleed test, about 30 to 45 minutes earlier in the countdown during the liquid hydrogen fast fill liquid phase for the core stage.

It sounds like they fixed the cooling problem but couldn't fix the hydrogen leak and instead sought to manage it with altered procedures.

Of the second failed launch attempt NASA said:

During today’s launch attempt, engineers saw a leak in a cavity between the ground side and rocket side plates surrounding an 8-inch line used to fill and drain liquid hydrogen from the SLS rocket. Three attempts at reseating the seal were unsuccessful. While in an early phase of hydrogen loading operations called chilldown, when launch controllers cool down the lines and propulsion system prior to flowing super cold liquid hydrogen into the rocket’s tank at minus 423 degrees F, an inadvertent command was sent that temporarily raised the pressure in the system. While the rocket remained safe and it is too early to tell whether the bump in pressurization contributed to the cause of the leaky seal, engineers are examining the issue.

With only a few days to practice those new procedures it's understandable that someone might have goofed.

In addition to determining the contribution that error might have made to the leak, they will examine the seal.

Then decide whether to replace and test it on the launch pad or inside the Vehicle Assembly Building.

[ Main Image: Artemis I. Credit: NASA via Twitter. ]

References

Kraft, Rachel (August 30, 2022). NASA Targets Sept. 3 for Next Artemis I Moon Mission Launch Attempt. NASA.

Karft, Rachel (September 3, 2022). NASA to Stand Down on Artemis I Launch Attempts in Early September, Reviewing Options. NASA.

NASA [@NASA] (September 4, 2022). #Artemis Update. Twitter.