SpaceX launches world's most powerful rocket toward Mars

The world's most powerful rocket, SpaceX's Falcon Heavy, blasted off today on its highly anticipated maiden test flight, carrying CEO Elon Musk's cherry red Tesla roadster to an orbit near Mars.

Screams and cheers erupted at Cape Canaveral, Florida as the massive rocket fired its 27 engines and rumbled into the blue sky over the same NASA launchpad that served as a base for the US missions to Moon four decades ago.

"Wow, did you guys see that? That was awesome," said SpaceX commentator Lauren Lyons as applause thundered through mission control.

Loaded with Musk's red Tesla and a mannequin in a spacesuit, the monster rocket's test voyage has captured the world's imagination.

About two minutes into the flight, the two side boosters peeled away and made their way back toward Earth for an upright landing.

Both rockets landed side by side in unison on launchpads, live video images showed.

"And the Falcons have landed," Lyons said.

The third, centre booster was to attempt a landing on an ocean platform.