Elon Musk's super-rocket has taken flight and overshot Mars' orbit, going further out into the solar system than originally planned.
His cherry-red Tesla, carrying a dummy and blasting Bowie's Life on Mars, was supposed to take a path around the Sun which would take it out into Mars' orbit.
It appears the super-strong rocket, with twice the firing power of any before it, overshot that trajectory and is has now pushed the Tesla into an orbit which extends into the asteroid belt between Mars and Jupiter.
The inventor's rockets are twice as strong as the Saturn V rockets, which carried men to the moon during the Apollo era.
Video footage from the Tesla showed it cruising into space for six hours, giving views of the Earth from the perspective of Elon Musk's old car.
The rocket was supposed to have one final engine burn before launching the car out into its final orbit, but it appears the engine was a little too strong.
The force of the rocket has shocked and impressed planetary scientists:
The successful launch of Falcon Heavy astounded half a million viewers, and delighted Musk, who had previously told reporters he gave the endeavor a 50:50 chance of success.
He said before the launch that he would consider it a success if the rocket exploded without damaging its launch pad.
However, viewers saw the rocket seamlessly launch into the air, towards Mars, in what some called the most spectacular feat since the 1960s.
Because the engine overshot, it is unclear what will happen to the car. Elon Musk previously said there was a tiny chance the vehicle would hit the surface of Mars on its expected path.
However, despite the unexpected trajectory, the rocket has shown it is capable of pushing objects out into deep space.
Also, many scientists want to one day mine asteroids for raw materials, so it is perhaps encouraging for them that the inventor has shown he can put objects into the asteroid belt.
President Donald Trump has praised Elon Musk, writing: "Congratulations @ElonMusk and @SpaceX on the successful #FalconHeavy launch. This achievement, along with @NASA's commercial and international partners, continues to show American ingenuity at its best!"
Nasa has also congratulated Space X, Musk's company, which used its launch pad.
Acting Nasa Administrator Robert Lightfoot congratulated the entire SpaceX team on the successful launch of the Falcon Heavy.
"All of us in this business know the effort it takes to get to a first flight of any new vehicle and recognise the tremendous accomplishment we witnessed today," he said.
"I am really proud of the hard work of our Nasa team, in particular at Kennedy, for the transformation into a multi-user spaceport. Watching the Falcon Heavy rise above the historic pad that has been the launch point for so many critical missions is a true testament to the hard work transitioning our nation's launch infrastructure in support of the commercial launch industry."
Kennedy Space Center Director Bob Cabana also expressed congratulations to Space X on the launch of the Falcon Heavy.
"The successful launch of a new vehicle on its first flight is a significant accomplishment they can be very proud of," he said. "As a multi-user spaceport, I look forward to the continued expansion of commercial spaceflight from Kennedy and the integration of a new class of launch vehicle into our Nation's space program."
British scientist Richard Dawkins tweeted: "Many congratulations to @elonmusk, visionary friend of science, and surely the world's greatest engineering designer."
Musk himself seemed awed at what his company had done.
After the launch, he admitted: "It's surreal to me."
He also said he had visions of it failing, explaining: "I had this image of a giant explosion on the pad, a wheel bouncing down the road and a Tesla logo landing somewhere.
"But fortunately, that's not what happened."
The inventor shared a picture from inside the car on social media, showing that a circuit board says: "Made on Earth by humans."
He wrote: "Printed on the circuit board of a car in deep space."
Falcon Heavy | All you need to know on Elon Musk's new rocket
Why was the rocket launch so important?
The Falcon Heavy's successful launch shows that it is possible to send heavy objects into space. The rocket can lift 64 tons - the weight of 5 London double-decker bosses - out of the Earth's atmosphere.
This means we can send better, heavier robots onto the surface of Mars, and perhaps start to explore outer planets such as Jupiter, Saturn and their moons.
It also means we can send larger satellites into space.
What makes it so powerful?
It has three boosters and 27 engines, making it doubly as powerful as the previous most powerful rocket.
What is it made of?
The Falcon Heavy is a combination of three Falcon 9s, the rocket that the company uses to ship supplies to the International Space Station and lift satellites. SpaceX is reusing first-stage boosters to save on launch costs. Most other rocket makers discard their spent boosters in the ocean.
What will it be used for?
The Heavy is intended for massive satellites, like those used by the US military and major-league communication companies. Even before the test flight, customers were signed up.