SpaceX's newest Starship vehicle just went up in smoke.

The company was testing a Starship upper stage at its Starbase site in South Texas on Wednesday night (June 18), to prepare for the megarocket's upcoming 10th flight test.

But something went very wrong, as video captured by NASASpaceflight.com shows: The vehicle exploded, sending a massive fireball high into the dark Texas skies.

SpaceX acknowledged the incident in an X post early on Thursday morning (June 19), noting that it occurred around 11 p.m. local time (midnight EDT and 0400 GMT on June 19).

"A safety clear area around the site was maintained throughout the operation and all personnel are safe and accounted for," SpaceX added in the post. "Our Starbase team is actively working to safe the test site and the immediate surrounding area in conjunction with local officials. There are no hazards to residents in surrounding communities, and we ask that individuals do not attempt to approach the area while safing operations continue."

SpaceX is developing Starship, the biggest and most powerful rocket ever built, to help humanity colonize Mars, among other ambitious exploration tasks.

The vehicle consists of two elements, both of which are designed to be fully and rapidly reusable — a first-stage booster called Super Heavy and a 171-foot-tall (52 meters) upper-stage spacecraft known as Starship, or simply Ship.

It was Ship that exploded on Wednesday night, on a test stand at Starbase's Massey site (not the orbital launch mount, from which Starship liftoffs occur). According to NASASpaceflight, which closely monitors Starship activity at Starbase, the anomaly occurred just before Ship was set to perform a static-fire test.

Static fires are common prelaunch tests, in which a rocket's engines are briefly ignited while the vehicle remains anchored to the ground. SpaceX had already conducted a static fire with this Ship, though that trial involved just one of its Raptor engines; this test may have been intended to fire up all six of them.

SpaceX has also already static-fired the Flight 10 Super Heavy booster, successfully igniting all 33 of its Raptors.