🚀 Artemis II: Mission Delayed? 😱

INVESTIGATION OF THE HELIUM FLOW INTERRUPTION
Last evening, the team was unable to get helium flow through the vehicle. This occurred during a routine operation to repressurize the system. Helium is used to purge the upper stage engine and pressurize its propellant tanks. The rocket is in a “safe configuration,” with a backup system providing purge air to the upper stage, NASA said in a statement. NASA encountered a similar failure signature during preparations for launch of the first SLS rocket on the Artemis I mission in 2022. On Artemis I, engineers traced the problem to a failed check valve on the upper stage that needed replacement. NASA officials are not sure yet whether the helium issue Friday was caused by a similar valve failure, a problem with an umbilical interface between the rocket and the launch tower, or a fault with a filter, according to Isaacman. In any case, technicians are unable to reach the problem area with the rocket at the launch pad.

THE ROLLBACK PREPARATION
Regardless of the potential fault, accessing and remediating any of these issues can only be performed in the VAB. That means NASA and contractor ground teams will immediately begin preparing to roll the 322-foot-tall (98-meter) SLS rocket off of Launch Complex 39B and back to the VAB. The rocket and its mobile launch platform will ride NASA’s crawler-transporter for the 4-mile journey. “Regardless of the potential fault, accessing and remediating any of these issues can only be performed in the VAB,” Isaacman wrote.

CRITICAL SCHEDULE IMPACT
As mentioned previously, we will begin preparations for rollback, and this will take the March launch window out of consideration. I understand people are disappointed by this development. That disappointment is felt most by the team at NASA, who have been working tirelessly to prepare for this great endeavor.

INTERNAL REPAIR OPERATIONS
Inside the VAB, ground teams will extend work platforms around the rocket to provide physical access to the upper stage and its associated umbilical connections. NASA said moving into preparations for rollback now will allow managers to potentially preserve the April launch window, “pending the outcome of data findings, repair efforts, and how the schedule comes to fruition in the coming days and weeks.”

BATTERY REPLACEMENT AND PREFLIGHT PROTOCOLS
NASA is also expected to replace batteries on the rocket’s flight termination system inside the VAB. The destruct system batteries currently on the rocket will expire next month. Astronaut Reid Wiseman, pilot Victor Glover, and mission specialists Christina Koch and Jeremy Hansen entered NASA’s standard preflight medical quarantine Friday. Now, they will be released to resume normal training activities.

VIBRATIONS AND THE CHALLENGED HUMBOLDT
Managers were pleased with the performance of newly-installed seals during Thursday’s countdown demonstration, but NASA officials have previously said vibrations from transporting the rocket to and from the pad could damage the seals. That rollout environment is very complicated,” said Amit Kshatriya, NASA’s associate administrator, earlier this month. “We think that’s a contributor.”