The National Aeronautics and Space Administration (NASA) has called off a rocket launch in its Artemis I mission due to a temperature issue with one of its four engines.

On Monday, a faulty liquid hydrogen line did not adequately chill one of the rocket’s four core-stage engines, part of the preparations needed before ignition.

“You don’t want to light the candle until it is ready to go,” Bill Nelson, the NASA administrator, said on NASA Television after the launch was postponed. “It’s just part of the space business.”

“Safety is always first. Following today’s #Artemis I launch attempt, @NASAArtemis teams are working through an issue with engine number 3 and expect to give a news briefing later today,” NASA tweeted.

The launch of the 322-foot Space Launch System rocket was initially scheduled for  

12:33 GMT. The uncrewed rocket was to launch from the Kennedy Space Center, Florida.

The Orion capsule was designed to orbit the moon and see whether it was safe for people to live on soon. The mission’s goal is to eventually set up an outpost on the moon for future Mars exploration and possible colonisation.

NASA argues that this launch and other moon missions are integral to its human spaceflight program and that it’s not a repeat of the Apollo moon landings from 1969 to 1972.

“It’s a future where NASA will land the first woman and the first person of colour on the moon,” Mr Nelson said during a news conference this month. “And on these increasingly complex missions, astronauts will live and work in deep space and will develop the science and technology to send the first humans to Mars.”

On March 18, 2021, NASA completed a “hot fire test” when the four engines in the core stage of the Space Launch System ignited and continued firing for more than eight minutes, performing what they would do during a trip to space but firmly anchored to the ground.