The two-stage rocketship, standing taller than the Statue of Liberty at 120m high, blasted off from the company’s Starbase spaceport and test facility east of Brownsville, Texas, on a planned 90-minute debut flight into space.
A live SpaceX webcast of the lift-off showed the rocketship rising from the launch tower into the morning sky as the Super Heavy’s 33 raptor engines roared to life in a ball of flame and billowing clouds of exhaust and water vapour.
Getting the Starship and its booster rocket off the ground together for the first time represents a milestone in SpaceX’s ambition of sending humans back to the moon and ultimately on to Mars – playing a pivotal role in Artemis, Nasa’s newly inaugurated human spaceflight programme.
A successful flight would instantly rank the Starship system as the most powerful launch vehicle on Earth.
A previous attempt on Monday to launch the Starship was scrubbed in the final minutes of countdown due to a frozen pressurisation valve.
Both the lower-stage Super Heavy booster and the upper-stage Starship vessel it carries to space are designed as reusable components, capable of flying back to Earth for soft landings.
Such a manouvre has become routine in dozens of missions for SpaceX’s smaller orbital-class Falcon 9 rocket.
But neither stage will be recovered from today’s launch.
Instead, both parts will end their inaugural flight to space with crash landings at sea – the lower stage falling into the Gulf of Mexico, the upper stage coming down in the Pacific after achieving nearly one full Earth orbit.
Prototypes of the Starship cruise vessel have made five sub-space test flights to altitudes of 10km in recent years, but the booster rocket has never left the ground.
In February, SpaceX conducted a test-firing of the Super Heavy, igniting 31 of its 33 engines for roughly 10 seconds with the rocket bolted in place vertically atop a platform.
The Federal Aviation Administration last Friday granted a licence for the first test flight of the fully stacked rocket system, clearing a final regulatory hurdle for the long-awaited launch.
The SpaceX announcement this week on Twitter that it planned a second launch attempt today after the first was scrubbed, amused many of Musk’s fans and detractors alike.
The tweet set off a flurry of jokes on the social media platform making reference to 4/20 as a date widely associated with cannabis culture, and to the notoriety Musk gained in 2018 when he smoked marijuana on a live web show.
Musk, who purchased Twitter last year for US$44 billion, is the founder, CEO and chief engineer of SpaceX.
He also is chief executive of electric carmaker Tesla Inc.
If all goes as planned today, the Starship will ascend on a flight most of the way around the Earth before it re-enters the atmosphere and free-falls into the Pacific at supersonic speed, about 97km off the coast of the northern Hawaiian islands.
After separating from the Starship, the Super Heavy booster is expected to execute the beginnings of a controlled return flight before plunging into the Gulf.
As designed, the Starship rocket is nearly two times more powerful than Nasa’s own Space Launch System (SLS), which made its debut uncrewed flight to orbit in November, sending a Nasa cruise vessel called Orion on a 10-day voyage around the moon and back.