SpaceX Falcon Heavy rocket successfully blasts off

The most powerful operational rocket in the world, SpaceX's Falcon Heavy, launched its first commercial mission on Thursday from Florida in a key demonstration for billionaire entrepreneur Elon Musk's space company in the race to grasp lucrative military launch contracts.

The 23-storey-tall Heavy, which previously launched Musk's cherry red Tesla roadster to space in a 2018 debut test flight, blasted off from Florida's Kennedy Space Center carrying its first customer payload.

"T plus 33 seconds into flight, under the power of 5.1 million pounds of thrust, Falcon Heavy is headed to space," SpaceX launch commentator John Insprucker said on a livestream.

Roughly three minutes after clearing the pad, Heavy's two side boosters separated from the core rocket for a synchronized landing at the Cape Canaveral Air Force Station.

The middle booster, after pushing the payload into space, returned nearly 10 minutes later for a successful landing on SpaceX's seafaring drone ship 645 kilometresoff the Florida coast. In the 2018 test mission, Heavy's core booster missed the vessel and crashed into the Atlantic Ocean.

Liftoff with Heavy's new military-certified Falcon 9 boosters was crucial in the race with Boeing-Lockheed venture United Launch Alliance and Jeff Bezos' Blue Origin as Musk's SpaceX, working to flight-prove its rocket fleet one mission at a time, aims to clinch a third of all U.S. National Security Space missions coveted military contracts worth billions.

The U.S. Air Force tapped SpaceX in 2018 to launcha classified military satellite for $130 million US. In February, it added three more missions in a $297-million contract.

Falcon Heavy carried a communications satellite for Saudi-based telecom firm Arabsat, which will beam Internet and television services over Africa, Europe and the Middle East.