NASA's Space Launch System rocket begins crawl to launch pad ahead of test flight around moon

The 322-foot- (98-metre)-tall rocket is scheduled to embark on its first mission to space, without any people, on August 29.

Moving less than 1.6 kilometres per hour, its transit took roughly 11 hours.

The SLS rocket will be powered by five-segment boosters and four RS-25 engines and will produce more than 3.9 million kilograms of thrust.

Sitting atop the rocket is NASA's Orion astronaut capsule, built by Lockheed Martin Corp.

The rocket is scheduled to return to Earth for an ocean splashdown 42 days later.

If bad launch weather or a minor technical issue triggers a delay, NASA has backup launch dates of September 2 and September 5.

NASA begins rolling out SLS and Orion to launch pad