For the second time in five days, NASA on Saturday halted a countdown in progress and postponed a planned attempt to launch the debut test flight of its giant, next-generation rocket, the first mission of the agency's moon-to-Mars Artemis program.

The latest attempt to launch the 32-story-tall Space Launch System (SLS) rocket and its Orion capsule was scrubbed after repeated attempts by technicians to correct a leak of super-cooled liquid hydrogen propellant being pumped into the vehicle's core-stage fuel tanks.

Pre-flight operations were officially called off for the day by Artemis I launch director Charlie Blackwell Thompson about three hours before the targeted two-hour launch window was due to open at 2:17 p.m. EDT (1817 GMT).

There was no immediate word on a time frame for retrying to launch the mission, dubbed Artemis I. But NASA could schedule another attempt for Monday or Tuesday.

(With input from Reuters)