Texas: SpaceX's next-generation spacecraft Starship, developed to carry astronauts to the moon and beyond in the coming decades, set off in a repeat test launch from southern Texas on Saturday.
The launch presumed to have failed minutes after the ship reached space.
"We have lost the data from the second stage... we think we may have lost the second stage," a SpaceX announcer said.
"Such an incredibly successful day," an announcer later said. "Even though we did have a... rapid unscheduled disassembly of both the super heavy booster and the ship."
SpaceX posted video of the Starship launch on X, the platform formerly known as Twitter. The rocket took off successfully, but Starship's booster exploded shortly after it separated from the ship. The rest of the spacecraft appeared to continue on track.
"As you could see, the super heavy booster has just experienced a rapid unscheduled disassembly however, our ship is still underway," a SpaceX announcer said during the livestream.
A SpaceX commentator said that the company had received data that will help it improve for the next launch.
The first attempt to launch the massive two-part rocket system, which consists of the Starship spacecraft and a Super Heavy booster, measuring a combined 397 feet (121 meters), failed spectacularly back in April when the rocket blew up four minutes after launch.
SpaceX owner Elon Musk said that an internal fire damaged Starship's engines and computers, causing it to stray off course, and that an automatic-destruct command was activated some 40 seconds too late.
Back on the ground, the launch pad was shattered by the force of the blast-off, which also sparked a 3.5-acre (1.4-hectare) brush fire, although no-one was injured.
Since then, the launch pad has been reinforced with a massive water-cooled steel plate, one of dozens of corrective measures that the US Federal Aviation Administration required before granting a launch license on Wednesday for the second test flight.
The primary mission objective this time around is to get Starship off the ground in Texas and into space, just shy of reaching orbit, before plunging back through Earth's atmosphere for a splashdown off the coast of Hawaii.
Starship's towering first-stage booster, propelled by 33 Raptor engines, produces 16.7 million pounds (74.3 meganewtons) of thrust, making it twice as powerful as the Saturn V rocket that sent the Apollo astronauts to the moon half a century ago.
The launch, which had been scheduled for Friday but was pushed back by a day for a last-minute swap of flight-control hardware, is vital for both Musk ultimately wants to use Starship to colonize Mars, and SpaceX's biggest customer NASA, which is aiming to return humans to the moon by the end of the decade.
Despite the dramatic failure of the last attempt, both SpaceX and NASA have insisted that such developments are normal, and even welcome.
SpaceX's engineering culture is considered more risk-tolerant than many of the aerospace industry's more established players and is built on a flight-testing strategy that pushes spacecraft to the point of failure, before fine-tuning through frequent repetition.
"How did they develop the [previous rocket system] Falcon 9?" commented NASA Administrator Bill Nelson. "They went through many tests and sometimes it blew up. Then they'd find out what went wrong, correct it and go back."
But time is ticking and NASA can't afford another failed launch if it wants to keep up with China's lunar ambitions.