NASA determining next steps after leak halts 3rd attempt to test mega moon rocket

Engineers working to determine cause of liquid hydrogen leak before trying to conduct wet dress rehearsal for fourth time

CAPE CANAVERAL, Fla. – NASA’s third attempt to finish a dress rehearsal for the Artemis moon rocket program ran into more technical issues on Thursday, causing officials to halt the countdown after a liquid hydrogen leak was discovered.

NASA said teams were loading fuel into the rocket when the engineers noticed the leak on the base of the mobile launcher.

The latest issue is the third technical problem that has forced the agency to stop the completion of the massive wet dress rehearsal for the 322-foot-tall Space Launch System rocket.

On Friday, NASA managers addressed the next steps for the required countdown dress rehearsal. 

Despite the latest issues, NASA's Artemis Mission Manager Mike Sarafin said "the mega moon rocket is fine."

Artemis-1 Launch Director Charlie Blackwell-Thompson said teams began troubleshooting on Friday to determine the culprit behind the leak. It's unclear if they will be able to fix the problem at the launchpad or if the SLS will need to make the 4-mile journey back to the Vehicle Assembly Building. 

Sarafin said there is another opportunity on April 21 to try for a fourth time to run through the wet dress rehearsal, but it's too early to say if the Artemis team will take that opportunity. 

SpaceX is also preparing to launch four astronauts for NASA on April 23 at the neighboring launchpad 39A. 

The SLS and Orion have been at launchpad 39B since March 19. Sarafin said the longer the rocket stays at the pad the more stress is placed on the vehicle. On the other side, a journey back to the Vehicle Assembly Building could also put stress on the massive moon rocket.

"It's 32 stories tall every time the wind blows against it it creates a bending moment and over time, that adds up," Sarafin said. "We got to weigh that against environmental exposure out in the field, but then also the rollback to the Vehicle Assembly Building to reattach a wet dress rehearsal actually put stress on the vehicle as well."

Earlier in the month, fans designed to prevent the buildup of hazardous gases failed during the initial countdown, and a valve meant to prevent a dangerous backflow of gases stopped properly functioning hours later.

As a result of the helium valve, NASA limited fuel tanking operations to avoid additional issues.


The series of technical issues could mean additional delays for the program that has already pushed back the timeline for returning astronauts to the moon.

When asked if the wet dress rehearsal will be completed before Artemis-1 launches. Sarafin said "it comes down to risk acceptance and in what we consider to be an acceptable level of risk."

Sarafin continued, "we are not done with our flight test program or our ground test program yet and we're not ready to make that determination just yet."

NASA officials tentatively planned for a June launch of the uncrewed Artemis I mission based on having a successful dress rehearsal.

The Artemis II mission was expected to follow, returning astronauts to the moon by 2025 and eventually leading to human exploration of Mars by 2040.