The agency’s enormous new moon rocket, the Space Launch System (SLS), closed up a more than 50-hour launch simulation named a “wet dress rehearsal” on Monday evening. After several failed attempts in April, mission team members could successfully fuel up the SLS for the first time on Monday, thereby finishing up a series of crucial prelaunch tests.
It was a significant achievement for the Artemis 1 moon mission. However, there were some obstacles along the way. Ground teams at NASA’s Kennedy Space Center (KSC) in Florida expended the weekend reviewing procedures and checklists for Artemis 1’s SLS, Orion capsule, and ground systems the exact way they would if they were preparing for an actual launch.
Monday’s activities mainly focused on filling the rocket’s cryogenic fuel tanks. The two-stage SLS utilizes liquid hydrogen (LH2) and liquid oxygen (LOX) as hypergolic propellants. Three attempts to fuel the rocket during a previous wet-dress test in April were stopped when the operators faced technical issues, including a high hydrogen leak in the Artemis 1 stack’s mobile launch platform (MLP).
The patch enabled the ground launch sequencer to practically skip over the automatic checks that would have recognized the leak. Still, the onboard flight systems for SLS were incapable of undergoing the same failsafe bypass. As intended, the terminal count continued through the T-33 second mark, at which point the ground computers handed flight control to SLS’s systems.