Editor’s note: NASA has updated an earlier version of this blog to provide additional details.
NASA is taking steps to potentially roll back the Artemis II rocket and Orion spacecraft to the Vehicle Assembly Building (VAB) at the agency’s Kennedy Space Center in Florida after overnight Feb. 21 observing interrupted flow of helium to the SLS (Space Launch System) rocket’s interim cryogenic propulsion stage. Teams are actively reviewing data, and taking steps to enable rollback positions for NASA to address the issue as soon as possible while engineers determine the best path forward. In order to protect for troubleshooting options at both Pad B and the VAB, teams are making preparations to remove the pad access platforms installed yesterday, which have wind-driven constraints and cannot be removed during high winds, which are forecasted for tomorrow.
The upper stage uses helium to maintain the proper environmental conditions for the stage’s engine and to pressurize liquid hydrogen and liquid oxygen propellant tanks. The systems worked during NASA’s Artemis II wet dress rehearsals, but teams were not able to properly flow helium during normal operations and reconfigurations following the wet dress rehearsal that concluded Feb. 19. Operators are using a backup method to maintain the environmental conditions for the upper stage engines and the rocket, which remains in a safe configuration.
Teams are reviewing potential causes of the issue, including in the interface between ground and rocket lines used to route helium, in a valve in the upper stage, and with a filter between the ground and rocket. They also are reviewing data from Artemis I in which teams had to troubleshoot helium-related pressurization of the upper stage before launch.
A rollback would mean NASA will not launch Artemis II in the March launch window. However, the quick preparations enable NASA to potentially preserve the April launch window if a rollback is required, pending the outcome of data findings, repair efforts, and how the schedule comes to fruition in the coming days and weeks.
NASA will continue to provide updates.
