NASA has called off a second attempt at a launchpad test of its next-generation rocket destined for lunar missions as part of the Artemis program.
NASA would have had to fill its powerful Space Launch System with fuel before conducting a mock countdown.
Engineers stopped the proceedings at Launch Complex 39B at the Kennedy Space Center in Florida late afternoon on Monday after they noticed a stuck valve on ground equipment linked to the test.
NASA explained in a post on its website that the teams encountered an issue with a panel on the mobile launcher that controls the core stage vent valve. The launch director made the decision to stop the test because of the time it took to resolve the issue.
A new schedule for the test will be decided after further investigation by the space agency.
A lot of great learning and progress had been achieved during Monday's efforts, the team said in a statement.
The first attempt at conducting the wet dress rehearsal took place on Sunday, April 3, but was called off after an issue was discovered with the rocket.
The Artemis I launch, which had been scheduled for next month, has been delayed because of the important rehearsal. It is not clear if the latest issues will affect the proposed date.
The Artemis I test flight will see the SLS rocket power the new spaceship. The fly-around of the moon will be performed by the team. If all goes to plan, Artemis II will fly the same path, but this time with a crew on board, while Artemis III will put the first woman and first person of color on the lunar surface in the first crewed touchdown since 1972.