NASA to replace faulty Artemis 1 hydrogen seal while rocket still at launch pad

NASA’s second attempt to launch the Artemis 1 mission had to be scrubbed because of a hydrogen leak in a “quick disconnect” interface between the Space Launch System (SLS) rocket and the liquid hydrogen fuel feed line. The space agency will replace the faulty seal that caused the leak while the rocket is still at the launchpad.
During a post-scrub press conference, associate adminrator for Exploration Systems Development James Free expressed his belief that the vehicle will have to be rolled back to the Vehicle Assembly Building (VAB) because the Flight Termination System (FTS) batteries on the board will likely have to be tested and recharged. But both Free and Artemis mission manager Michael Sarafin concluded that the final decision will lie with the Range Flight Safety team at the space agency, which addresses hazards during spaceflight operations.

While NASA would need to roll back the rocket back to the VAB based on current certification requirements, the space agency is yet to announce whether and when that is happening. NASA did announce yesterday that mission technicians will replace the faulty seal that caused the liquid hydrogen leak while the rocket is still at the launchpad.
For doing this, the technicians will set up an enclosure around the work area so that the hardware is protected from the weather and other environmental conditions. Replacing the faulty seal while the rocket is still at the launchpad presents an advantage: engineers can test the repairs under cryogenic (supercold) conditions. It also enables them to gather as much data as possible to better understand the issue.
After the seal is replaced, the rocket might be returned to the VAB so that additional work that does not require cryogenic testing. Apart from replacing the faulty seal, NASA teams will also check the plate coverings on other umbilical interfaces to make sure that no other leaks are present. The rocket has seven main umbilical line and each line may have multiple connection points.