Pioneering rocket firm SpaceX on Tuesday carried out what appears to be a seamless first-ever launch of its massive new rocket, called Falcon Heavy, CNN reports.

Falcon Heavy took flight at around 3:45 p.m. ET from Kennedy Space Center in Florida.

About two and a half minutes after launch, the two side boosters on the rocket detached and headed back to Earth.

Thousands of onlookers in Florida could be heard cheering on the company's livestream, which was viewed by about 3 million people.

The launch makes SpaceX, the company helmed by billionaire Tesla CEO Elon Musk, the owner of the world's most powerful operational rocket, noted CNN.

SpaceX managed to guide at least two of the Falcon Heavy's first-stage rocket boosters to land upright back on Earth. They cut back through the Earth's atmosphere and landed in unison at a Kennedy Space Center landing pad. The third booster was supposed to land on a sea-faring platform called a droneship, but it wasn't immediately clear if that landing was successful.

On board the rocket that's now headed deeper into space is Musk's personal Tesla (TSLA) roadster. At the wheel is a dummy dressed in a spacesuit, and the car is blaring David Bowie's "Space Oddity" on an endless loop.

Cameras on board the car showed it headed deeper into space. Musk plans to put the car into orbit around the sun.

Tuesday's success marked a huge step forward for the company which has already managed to shake up the rocket industry with its groundbreaking technology, noted CNN.

The company made headlines when it proved it can safely return first-stage rocket boosters to Earth with its Falcon 9 rocket, which the company has used for more than 40 missions dating back to 2012.

Those rockets have a single first-stage booster, and SpaceX has safely recaptured them after 21 Falcon 9 launches.

The company also routinely puts used boosters back to work, part of SpaceX's plan to drive down the cost of launches.