SpaceX launches giant rocket, but it explodes shortly after

Elon Musk's SpaceX on Thursday launched its next-generation Starship cruise vehicle for the first time atop the company's powerful new Super Heavy booster rocket, in a highly anticipated, uncrewed test flight from the Gulf Coast of Texas.

However, the combo exploded moments later, in what SpaceX described as a "rapid unscheduled disassembly."

The two-stage rocketship, standing taller than the Statue of Liberty at 394 feet (120 m) 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 program.

A successful flight would have instantly ranked the Starship system as the most powerful launch vehicle on Earth.

Both the lower-stage Super Heavy booster and the upper-stage Starship vessel it would carry to space are designed as reusable components, capable of flying back to Earth for soft landings — a manoeuvre that has become routine in dozens of missions for SpaceX's smaller orbital-class Falcon 9 rocket.

But neither stage would be recovered from Thursday's launch. Instead, both parts were to end their introductory flight to space with crash landings at sea. The lower stage will fall into the Gulf of Mexico after separating from the upper stage, which will come down in the Pacific Ocean after achieving nearly one full Earth orbit.

How the testing has gone so far

Prototypes of the Starship cruise vessel have made five sub-space test flights to altitudes of 10 kilometres 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 U.S. 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 on April 20, 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 for smoking marijuana on a live web show.

Musk, who purchased Twitter last year for $44 billion, is the founder, CEO and chief engineer of SpaceX. He also is chief executive of electric carmaker Tesla Inc.

As designed, the Starship rocket is nearly two times more powerful than NASA's own Space Launch System (SLS), which made its first crewless flight to orbit in November, sending a NASA cruise vessel called Orion on a 10-day voyage around the moon and back.