NASA moved a 322-foot-tall rocket out to the launchpad on Saturday, a key step as the agency prepares for a long-awaited mission to send four astronauts around the moon.

Nasa's mega rocket has been moved to the launch pad in Cape Canaveral, Florida, as the final preparations get underway for the first crewed mission to the Moon in more than 50 years.

Thousands of space centre workers and their families gathered in the pre-dawn chill to witness the long-awaited event, delayed for years.