SpaceX successfully launches most powerful rocket in world – before landing boosters back on the ground

'What an amazing day'

People watch as the SpaceX Falcon Heavy rocket lifts off from launch pad 39A at NASAs Kennedy Space Center on April 11, 2019 in Titusville, Florida (Joe Raedle/Getty Images)

SpaceX has successfully launched the most powerful rocket in the world, and then landed its boosters back down on the ground again.

The Falcon Heavy rocket has now conducted its first ever commercial mission, part of a plan to eventually conduct regular private launches up into space.

And Elon Musk's space company hopes to make those missions cheaper by landing the rockets back on the ground so they can be re-used.

This time around it was carrying a communication satellite called Arabsat, the rocket's first paying customer.

Eight minutes after lift-off from NASA's Kennedy Space Centre in Florida, SpaceX landed two of the first-stage boosters back at Cape Canaveral, side by side, just like it did for the rocket's debut last year.

The core booster landed two minutes later on an ocean platform hundreds of miles offshore - the only part of the first mission that missed.

"What an amazing day," a SpaceX flight commentator exclaimed. "Three for three boosters today on Falcon Heavy, what an amazing accomplishment."

The Falcon Heavy soared from the space centre using the same pad that shot Apollo astronauts to the moon half a century ago and later space shuttle crews.

Nearby beaches and other prime viewing spots were packed with tourists and locals eager to catch not just the launch but the rare and dramatic return of twin boosters, accompanied by sonic booms.

The roads were also jammed for Wednesday night's launch attempt, which was scuttled by high wind.

Because this was an upgraded version of the rocket with unproven changes, SpaceX chief Elon Musk cautioned in advance things could go wrong.

But everything went well and the satellite ended up in the proper orbit.

SpaceX employees at company headquarters in Southern California cheered every launch milestone and especially the three touchdowns.

"The Falcons have landed," Mr Musk said in a tweet that included pictures of all three boosters.

NASA offered swift congratulations.

"From our iconic launch pads at NASAKennedy, we will continue to support the growing commercial space economy," NASA tweeted.

The launch comes a year after Mr Musk put his own Tesla convertible on the initial test flight.

The red Roadster - with a mannequin, dubbed Starman, likely still at the wheel - remains in a solar orbit stretching just past Mars.

SpaceX plans to launch its next Falcon Heavy later this year on a mission for the US Air Force. The boosters for that flight may be recycled from this one.

NASA administrator Jim Bridenstine last month suggested possibly using a Falcon Heavy - and another company's big rocket - to get the space agency's Orion capsule around the moon, minus a crew, in 2020.

But the preferred method remains NASA's own Space Launch System mega rocket - if it can be ready by then.

SpaceX typically launches Falcon 9 rockets. The Falcon Heavy is essentially three of those single rockets strapped together.

Until SpaceX came along, boosters were discarded in the ocean after satellite launches. The company is intent on driving down launch costs by recycling rocket parts.

Additional reporting by agencies