SpaceX Mars Rocket Prototype Explodes, but This Time It Lands First

Two spectacular flights, two spectacular crash landings. The third time was almost the charm.

On Wednesday, SpaceX launched another high-altitude flight of Starship, a huge next-generation spacecraft that Elon Musk, the founder and chief executive of the private rocket company, dreams of sending to Mars. It returned to the ground and set down in one piece, but then lit up in another fiery blast minutes after the landing.

As the sun set over the test site in Boca Chica, Tex., close to Brownsville, the latest prototype, designated SN10, lifted off, its stainless steel exterior gaining a purple hue as it ascended toward an altitude of just over six miles, well below the orbital heights that SpaceX one day intends to achieve.

It was the second launch attempt of the day. Three hours earlier, liftoff was aborted with just a fraction of a second left in the countdown. The engines had already ignited but were then shut off when the computer on board the Starship detected too much thrust from one of the engines. The engineers decided that the problem was not significant, adjusted the software, refueled the rocket and tried again.

At about 6:15 p.m. Eastern time, the three engines ignited again, and this time they stayed on. The rocket rose into the Texas sky, and, by design, the engines shut down one by one as the rocket approached an altitude of six miles.

“Very nice, very nice,” said John Insprucker, a SpaceX engineer narrating the company’s webcast.

The Starship then tipped over to a horizontal position, in essence belly flopping through the atmosphere in a controlled fall back toward the ground. The rocket then fired its engines again to flip back into a vertical position and slowed down to a gentle landing.

As the smoke cleared, SN10 was still standing, but tilted. Mr. Insprucker declared the test a success. While earlier flights to this altitude had ended in fiery crashes, this time the rocket landed in one piece. But the landing legs appeared to fail, leaving the rocket standing but leaning at the landing pad.

“The key point of today’s test flight was to gather the data on controlling the vehicle while re-entering,” Mr. Insprucker said on the webcast. “And we were successful in doing so.”

A few minutes later, after SpaceX began its recovery operations of the vehicle and had concluded its video feed, video cameras operated by the website NASA Spaceflight captured an explosion that sent the rocket on an unplanned second hop, disintegrating in flames.

A leak in a propellant tank may have caused the explosion.

The previous test, on Feb. 2, occurred after a skirmish between SpaceX and the Federal Aviation Administration, which regulates rocket launches. The F.A.A. said that the earlier December launch had occurred without the agency’s approval. SpaceX had requested a waiver to conduct that flight even though it had not shown that a pressure wave that could be generated by an explosion during the test would not pose a danger to the public. The F.A.A. denied the request. SpaceX launched anyway.

After an investigation, the F.A.A. allowed SpaceX to go forward with the February launch. When that flight ended in another crash, the agency again asked for an investigation, which appears to have proceeded with less difficulty. The agency granted approval for the test on Wednesday.

Mr. Musk’s company has become successful in the launch business, and it is now one of the world’s most valuable privately held companies. Its Falcon 9 rockets have become a dominant workhorse for sending satellites to orbit. It routinely transports cargo to the International Space Station, and lifted NASA astronauts there twice in 2020, with more trips planned this year.

However, many are skeptical about Mr. Musk’s assertion that the company is just a few years from sending a Starship to Mars, saying he has repeatedly set timelines for SpaceX that proved far too optimistic in how quickly they have come to pass.

In 2019, when he provided an update on the development of Starship, he said a high-altitude test would occur within months and that orbital flights could occur early in 2020.

Instead, several catastrophic failures happened because of faulty welding. When the propellant tanks stopped rupturing, two of the prototypes made short successful flights last year. Those earlier Starship prototypes resembled spray paint cans with their labels removed, rising nearly 500 feet using a single rocket engine before setting back down at the Texas test site.

In a video released on Tuesday night, Mr. Musk said Starship would be ready to launch people to orbit and beyond by 2023. He made the remarks in a video released by Yusaku Maezawa, a Japanese entrepreneur who is helping to financially underwrite the development of Starship. Mr. Maezawa intends to fly on an approximately weeklong trip around the moon and back to Earth.

In the Tuesday video, Mr. Maezawa announced that he wanted to bring eight passengers on the lunar voyage, and invited applications from people wishing to go. On Wednesday, he said more than 100,000 people have already expressed interest.