SpaceX's Starship – the biggest and most powerful rocket ever built – blasted off from the southern tip of Texas on Thursday morning.
However, just minutes later and awaiting stage separation, it experienced a failure – what SpaceX livestream hosts described as a "rapid unscheduled disassembly."
The rocket began to tumble and then exploded four minutes into the flight, tumbling down into the Gulf of Mexico.
The cause of the failure was not immediately clear.
"Congrats @SpaceX team on an exciting test launch of Starship! Learned a lot for next test launch in a few months," SpaceX founder Elon Musk tweeted a short time later.
SpaceX said on Twitter that its teams would continue to review data and work toward the next flight test.