https://techcrunch.com/2022/08/29/nasa-scrubs-artemis-i-launch-due-to-technical-issue/

After much fanfare, including a crop of celebrity appearances and the arrival of Vice President Kamala Harris, NASA said it was scrubbing today’s first-ever launch attempt of the mega moon rocket due to technical issues.

The mission was scrubbed at T-40 minutes after engineers were unable to resolve an engine bleed issue. “The engine bleed couldn’t be remedied,” NASA communications officer Derrol Nail said. NASA has another launch opportunity on September 2, but Nail suggested that “we must wait to see what shakes out” from the data as to whether a launch can be attempted on that date.