New York (dpa) - A SpaceX rocket exploded during a test flight, after attempting a flipping manoeuvre that led to a thruster failing to work on Tuesday.

After a seemingly perfect take-off in Cameron County, Texas, the rocket reached the peak of its flight and hovered in mid-air. It shut off its engines and performed a flip to descend nose-down.

However, one of the thrusters failed to reignite and the Starship SN9 went up in flames some six and a half minutes after take-off.

It then crashed back to earth just like the SN8 predecessor prototype before it in December.

The "Starship" prototype had previously ascended to an altitude of around 12.5 kilometres.

The aim of the experiments is to test individual elements of the new rocket.

According to plans by SpaceX boss Elon Musk, Starship will someday transport cargo and people to the moon and Mars.

Musk wants to make Starship completely reusable. Flipping mid-flight and descending under "active aerodynamic control" are key to landing where runways and launchpads do not exist, on Mars for instance, SpaceX says.