Everything went perfectly except for one little problem at the end.

Elon Musk’s space-transportation company SpaceX blasted its Starship spacecraft nearly 8 miles high and maneuvered it back seemingly to a pinpoint landing, but then suffered a spectacular explosion as the vehicle failed to slow down before smashing into the ground.

Wednesday’s sequence of events even prompted an elated Mr. Musk initially to post a message on Twitter that the 16-story Starship prototype executed a key airborne maneuver precisely and made it back to the designated landing point. Checking the craft’s ability to control its direction during descent was one of the main reasons for the flight, the first high-altitude test of the private vehicle designed to explore the solar system.

But within minutes, after a video feed showed a fireball at the instant of touchdown, Mr. Musk posted a follow-up tweet explaining that low fuel pressure “during the landing burn contributed to the high touchdown velocity and the massive explosion.”

Still, the company’s founder and chief technical officer added there was good news because the team “got all the data” it needed during the mission. “It appears everything is in order for future tests,” he said.

Elon Musk’s space-transportation company SpaceX blasted its Starship spacecraft nearly 8 miles high and maneuvered it back seemingly to a pinpoint landing, but then suffered a spectacular explosion as the vehicle failed to slow down before smashing into the ground.

Wednesday’s sequence of events even prompted an elated Mr. Musk initially to post a message on Twitter that the 16-story Starship prototype executed a key airborne maneuver precisely and made it back to the designated landing point. Checking the craft’s ability to control its direction during descent was one of the main reasons for the flight, the first high-altitude test of the private vehicle designed to explore the solar system.

But within minutes, after a video feed showed a fireball at the instant of touchdown, Mr. Musk posted a follow-up tweet explaining that low fuel pressure “during the landing burn contributed to the high touchdown velocity and the massive explosion.”

Still, the company’s founder and chief technical officer added there was good news because the team “got all the data” it needed during the mission. “It appears everything is in order for future tests,” he said.