SpaceX's Starship megarocket roared into the skies on Tuesday on its 10th test flight, turning in a strong performance after a series of failures had begun to cast doubt on its future.

Towering 123 meters, Starship is the most powerful launch vehicle ever built and key to founder Elon Musk's vision of carrying humanity to Mars, as well as Nasa's plans to return astronauts to the Moon.

The stainless steel colossus blasted off from the company's Starbase in southern Texas at 6.30pm local time, greeted by loud cheers from engineering teams, as seen in a live webcast.

A few minutes into launch, the first-stage booster known as Super Heavy splashed down into the Gulf of Mexico, triggering a sonic boom on its way.

Unlike other recent tests, SpaceX opted not to attempt a catch with the giant "chop stick" arms of the launch tower, instead testing how it would perform if an engine cut out.

Attention then shifted to the upper stage -- also known individually as Starship and intended to one day carry crew and cargo -- to demonstrate its capabilities as it soared into space.

For the first time, SpaceX was able to successfully deploy eight dummy Starlink internet satellites, with onboard cameras beaming back live views of a robotic mechanism pushing each out one by one.

It was not all smooth sailing.

Some heat tiles fell away and a small section of a flap burned off during the vessel's fiery descent, as it was enveloped in pink and purple plasma.

But SpaceX communications manager Dan Huot said much of this was expected as the vehicle was intentionally flown on a punishing trajectory with some tiles removed.

"We're kind of being mean to this starship a little bit," he said on the webcast.

"We're really trying to put it through the paces and kind of poke on what some of its weak points are."

"Great work by the SpaceX team!!" Musk wrote on X. (AFP)