Problem pops up during SLS roll back after wet dress rehearsal countdown
Not so fast! According to an update posted by NASA today, during the process to roll back the SLS rocket from the launchpad following the wet dress rehearsal countdown two days ago, crews suddenly detected “interrupted helium flow” in the upper stage that appears to be of some concern.
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 in the SLS (Space Launch System) rocket’s interim cryogenic propulsion stage. Helium flow is required for launch.
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. This will almost assuredly impact the March launch window. NASA will continue to provide updates. [emphasis mine]
The helium flow is likely used to fill the tanks as the actual and dangerous fuel is pumped out. They need to drain those tanks in order to roll the rocket from the launchpad. If it has stopped flowing, it means they can’t drain the tanks as planned.
During launch the helium is also likely pumped into the tanks to maintain pressure as the fuel burns. If during launch the helium stopped flowing it would almost certainly result in a failed launch.
This issue not only impacts the tentative March 6th launch date that NASA announced yesterday, if a fix is not found quickly it almost certainly means no launch can occur before this launch window closes on April 6th.
Not so fast! According to an update posted by NASA today, during the process to roll back the SLS rocket from the launchpad following the wet dress rehearsal countdown two days ago, crews suddenly detected “interrupted helium flow” in the upper stage that appears to be of some concern.
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 in the SLS (Space Launch System) rocket’s interim cryogenic propulsion stage. Helium flow is required for launch.
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. This will almost assuredly impact the March launch window. NASA will continue to provide updates. [emphasis mine]
The helium flow is likely used to fill the tanks as the actual and dangerous fuel is pumped out. They need to drain those tanks in order to roll the rocket from the launchpad. If it has stopped flowing, it means they can’t drain the tanks as planned.
During launch the helium is also likely pumped into the tanks to maintain pressure as the fuel burns. If during launch the helium stopped flowing it would almost certainly result in a failed launch.
This issue not only impacts the tentative March 6th launch date that NASA announced yesterday, if a fix is not found quickly it almost certainly means no launch can occur before this launch window closes on April 6th.









