A prototype of a SpaceX rocket the company hopes will one day journey to Mars crashed in a fireball as it tried to land upright after a test flight Tuesday.

It was the second such accident after the last prototype of Starship met a similar fate in December.

"We had again another great flight," said SpaceX announcer John Insprucker on an online broadcast. 

"We've just got to work on that landing a little bit," he added.

The company's founder Elon Musk was uncharacteristically quiet on social media, having announced the night before he was "Off Twitter for a while."

The stainless steel rocket, dubbed SN9 or "Serial Number 9," was cleared for lift-off from Boca Chica, Texas by the US Federal Aviation Administration (FAA) less than a day earlier.

The rocket launched smoothly around 2:35 pm local time (2035 GMT) and progressively shut down its engines as it reached a height of six miles (10 kilometers), then performed a series of test maneuvers in a horizontal "belly flop" position.

It was when the rocket attempted to return to a vertical position for landing that the problems began, with the footage showing it came in too fast and at a bad angle.

https://www.youtube.com/watch?v=klT3YcrG7K4

It landed with a deafening crash, and exploded into bright orange flames and a dust cloud, but the fire did not spread.

The company's next prototype rocket, SN10, appeared to be undamaged on a nearby launchpad.

Insprucker put a positive spin on the crash.

"We demonstrated the ability to transition the engines to the landing propellant tanks," he said. "The subsonic reentry looked very good and stable like we saw last December, so we've got a lot of good data on flap control."

The company intends to proceed with its next launch "in the near future," he added.

- Waiver drama -
Tuesday's launch was delayed by several days over problems stemming from SpaceX's last Starship test on December 9, which also went up in flames.

SpaceX had sought a waiver to exceed the maximum allowable risk to the public of Starship SN8.

The FAA denied the request, but SpaceX went ahead anyway, landing the company in hot water.

The regulator denied SpaceX the opportunity to launch last week and asked them to carry out corrective actions, finally granting its approval Monday night.

The company hopes the reusable, 394-foot (120-meter)  rocket system will one day carry crew and cargo to fly to the Moon, Mars and beyond.