NASA calls off 2nd launch attempt for Artemis I — and next attempt not likely until at least late September

NASA called off its second launch attempt of the Artemis I moon mission on Saturday after crews were unable to fix a liquid hydrogen leak.

Another attempt isn't likely until later this month at least — but it too may be unlikely as it conflicts with the SpaceX Crew-5 mission to the International Space Station, which is scheduled for an Oct. 3 launch.

The SLS core stage — the big orange rocket — contains both liquid oxygen (LOX) and liquid hydrogen (LH2). They both need to have a staggered load. As of 10:13 a.m. ET, LOX was fully loaded. LH2 loading was put on hold for 30 minutes to see if warming it up would seal the leak. 

At 10:15 a.m., the teams resumed loading the LH2 but the problem persisted. The launch was scrubbed at 11:17 a.m.

There will not be a launch attempt on Sept. 5, the next scheduled window, Artemis I mission officials said at an afternoon news conference.  The leak is too complex to be fixed in the coming days and the next steps will be determined by whether tests can be carried out on the launch pad, they said. 

Officials clarified they will have to roll the spacecraft back to the Vehicle Assembly Building. 

"We do not launch until we think it's right," NASA administrator Bill Nelson said. 

Jim Free, an associate NASA administrator, told reporters later launch periods will depend on what options are presented early next week. 

Earlier launch scrubbed

On Monday, the space agency was unable to launch its rocket, the Space Launch System (SLS) with its Orion spacecraft for Artemis I — an uncrewed mission around the moon. 

The space agency came up against several issues on Monday. First, it was a delay in loading the propellants into the SLS due to nearby lightning, which was a roughly 40-minute hold. Then, once they were able to start, there was an issue with the rate at which the liquid hydrogen and liquid oxygen were loading, which meant another brief hold. 

But Artemis mission manager Mike Serafin explained Saturday's leak was much larger and not as manageable. Serafin said the team made sure it exhausted all of its options before deciding to scrub the launch. 

NASA had a two-hour launch window, beginning at 2:17 p.m. ET.

A day earlier, Jeremy Parsons, the deputy manager at the Kennedy Space Center's Exploration Ground Systems, expressed optimism about prospects for Saturday's launch attempt. 

"And right now the team has really done a fantastic job getting us out of launch attempt number one, repairing all the issues and getting us into a safe configuration," he told media on Friday. 

On Monday, there was a similar hydrogen leak, however today's leak was in a different location.

NASA then encountered another issue with a helium leak. They had run into this previously on their wet dress rehearsals, which involve a sort of mock launch, going through all the steps of a real attempt without actually lifting off.

What ultimately did in Monday's launch attempt was an issue with one of the rocket's RS-25 engines. Engine three showed that it had not cooled properly, and — due to all the other holds — they ran out of time and had to scrub the launch.

"The cost of two scrubs is a lot less than a failure," said Nelson.

Mission officials said any further delay to the Artemis I launch would not affect future missions, including Artemis II, planned for 2023, and Artemis III in 2025.

The next update on the mission is expected to be next week.