For August 29 mission, called Artemis 1, the Orion capsule will launch atop the Space Launch System without any humans and orbit the Moon before returning to Earth for an ocean splashdown 42 days later.

The rocket is part of a multibillion-dollar US effort to return humans to the lunar surface as practice for future missions to Mars.
The rocket is part of a multibillion-dollar US effort to return humans to the lunar surface as practice for future missions to Mars. (Reuters)

NASA's gigantic Space Launch System Moon rocket, topped with an uncrewed astronaut capsule, has begun an hours-long crawl to its launchpad ahead of the behemoth's debut test flight this month.

The Space Launch System, whose development in the past decade has been led by Boeing is scheduled to emerge from its assembly building at NASA's Kennedy Space Centre in Florida around 9 pm EDT on Tuesday (0100 GMT on Wednesday) and begin the 6 km trek to its launchpad. 

Moving less than1.6 km per hour, the rollout takes roughly 11 hours.

The 322-foot-tall rocket is scheduled to embark on its first mission to space — without any humans — on August 29. 

It will be a crucial, long-delayed demonstration trip to the Moon in NASA's Artemis programme, the United States' multi-billion dollar effort to return humans to the lunar surface as practice for future missions to Mars.

READ MORE: Return to Moon: NASA to launch uncrewed test flight next month

Artemis mission

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

It is designed to separate from the rocket in space, ferry humans toward the Moon's vicinity and rendezvous with a separate spacecraft that will take astronauts down to the lunar surface.

But for the August 29 mission, called Artemis 1, the Orion capsule will launch atop the Space Launch System without any humans and orbit around the Moon before returning to Earth for an ocean landing 42 days later.

If bad launch weather or a minor technical issue triggers a delay from August 29, the National Aeronautics and Space Administration has backup launch dates on September 2 and September 5.

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Source: Reuters