SpaceX launched the world's most powerful rocket on a critical 13th test flight late Friday, but there was no triskaidekaphobia on this mission.

The July 24 test launch, Space's Starship Flight 13 mission, sent a towering rocket the size of a 40-story skyscraper into space from South Texas, returned its massive Booster to Earth, and then — in a feat perhaps none saw coming — gently landed its Starship upper stage in the Indian Ocean, where it tipped over to float belly up on the sea.

"Starship is intact, floating in the ocean and transmitting telemetry!" SpaceX CEO Elon Musk wrote on X.

"That is a first," SpaceX spokesperson Dan Huot added in live commentary as a drone beamed stunning views of Starship bobbing in the waves. "That is the softest splashdown we have ever had with Starship in the Indian Ocean."

The splashdown capped what appeared to be a mostly successful test flight of SpaceX's biggest Starship ever. With a mighty roar, Starship Flight 13 lifted off from SpaceX's Starbase, Texas launch site at 6:51 p.m. EDT (2251 GMT) on a test flight that lasted just over one hour.

It was only the second flight of the company's new Starship Version 3 design, or V3, and SpaceX was hoping for a better outing than its first attempt in May. During that previous test, the Starship Flight 12 mission, the massive Super Heavy first-stage Booster suffered engine problems after stage separation and failed to make a water landing in the Gulf of Mexico. It crashed instead.

SpaceX initially tried to launch Flight 13 on July 16, but the rocket aborted the try at the last second due to engine issues. SpaceX replaced some first-stage Raptor engines in time for a July 23 launch attempt, but waved off due to weather, setting the stage for Friday's successful liftoff.

Minutes into the flight, the Super Heavy Booster successfully separated from its Ship upper stage, aced a flip maneuver and returned to Earth. There was a problem during the landing burn. Only five engines appeared to fire when 13 were required to slow the Booster to landing speed. It hit the Gulf waters harder than planned, its camera views cutting out.

"It didn't look like we lit all 13 engines that we were planning for that initial landing burn," Huot said. "We were targeting a softer splashdown and, as you saw, it came in with quite a bit of velocity."