NASA last evening posted an update on the status of its SLS rocket, noting that engineers had located the seal that had caused the helium flow issue in the upper stage during unfueling after the wet dress rehearsal two weeks ago.

Engineers determined a seal in the quick disconnect, through which helium flows from the ground systems to the rocket, was obstructing the pathway. The team removed the quick disconnect, reassembled the system, and began validating the repairs to the upper stage by running a reduced flow rate of helium through the mechanism to ensure the issue was resolved. Engineers are assessing what allowed the seal to become dislodged to prevent the issue from recurring.

Though this information is somewhat vague, it strongly suggests the seal with the problem was in the upper stage, not the umbilical line that is part of the ground systems.

Before they can return the rocket to the launchpad, they need to make sure they identified the exact issue that caused the seal to not work properly. They also are replacing the batteries in the rocket’s self-destruct system as well as flight batteries in the upper stage, core stage, and two strap-on solid-fueled boosters. It also appears they are replacing another seal the oxygen feed line for the core stage.

Once this work is finished and confirmed, they will still need to roll SLS back to the launchpad and likely do another wet dress rehearsal countdown, though that rehearsal might be condensed to focus on these issues specifically.

The present launch window closes on April 6th, so the timeline is very tight. NASA management is reviewing later windows in late April as well as May and June.

Despite the major reshaping of the later missions in the Artemis program that NASA administrator Jared Isaacman announced last week, this upcoming Artemis-2 mission remains the same, a ten-mission carrying four astronauts around the Moon using an Orion capsule with a questionable heat shield and an untested life support system.