NASA repairs Artemis 2 rocket, continues eyeing April moon launch

NASA has repaired its Artemis 2 rocket, apparently keeping things on track for a possible April launch of the first crewed moon mission in more than 50 years.

Engineers made a fix that aims to restore consistent helium flow to the upper stage of Artemis 2's Space Launch System (SLS) rocket, agency officials announced in an update on Tuesday (March 3).

"Work on the rocket and spacecraft will continue in the coming weeks as NASA prepares for rolling the rocket out to the launch pad again later this month ahead of a potential launch in April," NASA wrote in the update.

The repair work occurred inside the huge Vehicle Assembly Building (VAB) at NASA's Kennedy Space Center (KSC) in Florida.

Artemis 2's SLS and Orion crew capsule have been in the VAB since Feb. 25, when they rolled back to the hangar from KSC's Launch Pad 39B. Just a few days earlier, the Artemis 2 stack successfully completed a wet dress rehearsal, a two-day-long practice run of the procedures leading up to launch.

In the wake of that test, however, NASA noticed an interruption in helium flow in the SLS' upper stage. That was a significant issue, because helium pressurizes the rocket's propellant tanks. Rollback was the only option, as the affected area in the upper stage was not accessible at the pad.

The problem took a potential March launch out of play for Artemis 2, which will send four astronauts on a roughly 10-day flight around the moon. It will be the first crewed flight to the lunar neighborhood since Apollo 17 in 1972.

The next Artemis 2 launch window opens in April, with liftoff opportunities on April 1, April 3-6 and April 30. And those options apparently remain in play, thanks to recent work in the VAB.

That work centered on a seal in an interface through which helium flows from ground equipment into the SLS upper stage. That seal was obstructing the interface, which is known as a quick disconnect.

"The team removed the quick disconnect, reassembled the system, and began validating the repairs to the upper stage by running a reduced flow rate of helium through the mechanism to ensure the issue was resolved," NASA officials wrote in Tuesday's update. "Engineers are assessing what allowed the seal to become dislodged to prevent the issue from recurring."

The Artemis 2 team is using its VAB time in other ways as well. For example, technicians are replacing flight batteries on the SLS' core stage, upper stage and solid rocket boosters and charging Orion's emergency-abort batteries. They're also "activating a new set of flight termination system batteries ahead of end-to-end retesting of the system," NASA officials wrote.

This latest Artemis 2 news follows a bigger announcement — that NASA is restructuring the Artemis program. For example, Artemis 3 will no longer be the first mission in the program to land astronauts on the moon; that will now be Artemis 4, which is targeted to fly in 2028. Artemis 3 will stay in Earth orbit and feature a rendezvous between Orion and one or both of the private moon landers that NASA has contracted for the Artemis program.