NASA has postponed for at least four days the debut test flight of its next-generation moon megarocket.
Technical problems scuppered the launch of the first rocket in NASA's Artemis project, a planned six-week uncrewed voyage around the moon and back 50 years after Apollo's last lunar mission.
The countdown clock was halted about 40 minutes before the targeted launch time of 8:33 am EDT (1233 GMT), as the 32-story-tall, two-stage Space Launch System (SLS) rocket and its Orion crew capsule awaited liftoff from the Kennedy Space Center in Cape Canaveral, Florida.
The US space agency cited a problem detected on one of the rocket's main engines, after launch teams had begun filling the rocket's core fuel tanks with super-cooled liquid oxygen and hydrogen propellants.
NASA did not give a new launch date but said its first available backup launch opportunity was set for Friday, September 2.
The launch of #Artemis I is no longer happening today as teams work through an issue with an engine bleed. Teams will continue to gather data, and we will keep you posted on the timing of the next launch attempt. https://t.co/tQ0lp6Ruhv pic.twitter.com/u6Uiim2mom— NASA (@NASA) August 29, 2022