Shortly after 10:30 AM ET on Saturday, NASA Administrator Jared Isaacman posted on X that Artemis II will likely have to return to the VAB and that it is “almost assuredly” going to affect the March window.

After overnight data showed an interruption in helium flow in the SLS interim cryogenic propulsion stage, teams are troubleshooting and preparing for a likely rollback of Artemis II to the VAB at @NASAKennedy. This will almost assuredly impact the March launch window. @NASA will…

— NASA Administrator Jared Isaacman (@NASAAdmin) February 21, 2026

Preparations for the rollback and any move itself may be delayed by a cold front expected to arrive Sunday evening, bringing blustery conditions. NASA stated as much, saying today that, “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.”

Jared Isaacman later gave more detail into the events that led to this unexpected news:

As an update to my earlier post.

– The ICPS helium bottles are used to purge the engines, as well as for LH2 and LOX tank pressurization. The systems did work correctly during WDR1 and WDR2.

– Last evening, the team was unable to get helium flow through the vehicle. This… https://t.co/Qte3nEXwQb

— NASA Administrator Jared Isaacman (@NASAAdmin) February 21, 2026

April Window

The bad news is that a nearly two-month delay may be ahead. The good news, if you will, is that April offers some late afternoon or early evening launch windows, with one opening right at a perfect time for a jellyfish if the rocket were to launch then.