The first launch of SLS, on Artemis I, has been a long time coming. With the SLS that will launch for Artemis I at the pad for its wet dress rehearsal, teams have resumed the test that was cut short last week due to valve issues.
Last week, as NASA teams worked through the wet dress rehearsal, issues arose with a helium check valve in the rocket’s interim cryogenic propulsion stage (ICPS).
The delay pushed the wet dress rehearsal until after the launch of Axiom-I.
In order to fix the affected valve, SLS will need to return to the vehicle assembly building, but instead of wasting all that time, NASA will perform a modified wet dress rehearsal.
NASA is planning to proceed with a modified wet dress rehearsal, primarily focused on tanking the core stage, and minimal propellant operations on the interim cryogenic propulsion stage (ICPS) with the ground systems at Kennedy. Due to the changes in loading procedures required for the modified test.[…]
Following the modified test, the Space Launch System rocket and Orion spacecraft will return to the Vehicle Assembly Building (VAB) where engineers will evaluate the valve and replace if needed. Teams are confident in the ability to replace the valve once back in the VAB.NASA Artemis I WDR update
On the night of April 12 leading into April 13, NASA teams powered up the core stage of the rocket and the Orion spacecraft. Teams will review the status of the rocket and spacecraft and provide an update on later today, April 13.
Tanking of SLS at 39B is scheduled to begin on Thursday, April 14.
NASA will provide regular updates on the test via the NASA Exploration Ground Systems Twitter account.