WASHINGTON－SpaceX's Starship prototype exploded while attempting to land on Wednesday after an otherwise successful test launch from the company's rocket facility in Boca Chica, Texas, live video of the flight showed.

This latest prototype－the first one equipped with a nose cone, body flaps and three engines－was shooting for an altitude of more than 10 kilometers. That's almost 100 times higher than previous hops and skimming the stratosphere.

The launch and ascent of Starship SN8 were successful, but as the engines appeared to reignite for landing, the vehicle flipped back to vertical and then slammed into the ground.

The Starship rocket destroyed in the accident was a 16-story-tall prototype for the heavy-lift launch vehicle being developed by entrepreneur Elon Musk's private space company to carry humans and 100 tons of cargo on future missions to the moon and Mars.

The self-guided rocket blew up as it touched down on a landing pad following a controlled descent. The test flight had been intended to reach an altitude up to 12.5 km, propelled by three of SpaceX's newly developed Raptor engines for the first time. But the company left unclear whether the rocket had flown that high.

The company said Starship SN8 lifted off from the launchpad in Cameron County, Texas, and successfully ascended, transitioned propellant, and performed its landing flip maneuver with precise flap control to reach its landing point.

Landing failure

Musk said in a tweet immediately following the landing mishap that the rocket's "fuel header tank pressure was low" during descent, "causing touchdown velocity to be high".

He added that SpaceX had obtained "all the data we needed" from the test and hailed the rocket's ascent phase a success.

SpaceX made its first attempt to launch Starship on Tuesday, but a problem with its Raptor engines forced an automatic abort just one second before liftoff.

The complete Starship rocket, which will stand 120.09 meters tall when mated with its super-heavy first-stage booster, is the company's next-generation fully reusable launch vehicle－the center of Musk's ambitions to make human space travel more affordable and routine.

NASA awarded SpaceX $135 million to help develop Starship, alongside competing vehicles from rival ventures Blue Origin, the space company owned by Amazon founder Jeff Bezos, and Leidos-owned Dynetcis.

The three companies are vying for future contracts to build the moon landers under NASA's Artemis program, which calls for a series of human lunar explorations within the next decade.

Right before Wednesday's launch, NASA announced the 18 US astronauts to be trained for the Artemis moon-landing program.

Agencies - Xinhua