NASA returning to the Moon with mega rocket launch

NASA was readying to launch its new mega Moon rocket early Wednesday from Florida-but technical issues threatened to play spoilsport a third time.

Engineers were forced to pause flowing liquid hydrogen into the core stage because of a valve leak in the mobile launcher ground structure, as a team was sent out to address the problem.

If the issue is resolved, weather remains 90 percent favorable for lift-off during a two hour window that begins at 1:04 am local time (0604 GMT).

The Artemis 1 mission, a test flight without astronauts, represents the first step in the US space agency's plan to build a lasting presence on the Moon and take lessons from there to prepare for a future voyage to Mars in the 2030s.

Named after the sister of Apollo in Greek mythology, the new space program comes 50 years after humans last set foot on lunar soil.

It will be the first launch of the 32-story tall Space Launch System rocket, the most powerful ever built.

For now, countdown remains paused at the storied Kennedy Space Center, where the orange and white behemoth awaits its maiden flight.

The takeoff is scheduled less than a week after the passage of Hurricane Nicole, which the rocket endured outside on its launch pad.

The hurricane damaged a thin strip of caulk-like material which encircles the Orion crew capsule atop the rocket, making it more aerodynamic. However, NASA said Monday that this posed a minimal risk.

Two backup dates are possible, if needed, on November 19 and 25.