Elon Musk: SpaceX’s runaway starship battled self-destruct

During its brief maiden flight more than a week ago, SpaceX’s gargantuan Starship rocket produced an unexpected “rock tornado” on launch, and several engines failed as it soared upward before spiraling out of control.

Then, Elon Musk, the company’s founder, said in an update shared during a Twitter audio chat Saturday night, the end of the flight was more tense than it should have been. An automated self-destruct command did not immediately destroy Starship. Instead, 40 seconds elapsed before the rocket finally exploded.

Despite everything that went wrong, Mr. Musk considered the launch of Starship a success.

“Of course not a complete success,” he said, “but still successful.”

He said the aim of the test flight was “to learn a lot, and we learned a lot” and that more test flights are planned for this year.

The spacecraft, the most powerful ever launched, is central to SpaceX’s goals of bringing humans to Mars, as well as NASA’s plans to return astronauts to the moon as part of the Artemis program by 2025.

Although the rocket didn’t make it into space, “the result was about what I expected and perhaps slightly exceeded my expectations,” Mr Musk said, noting that it “got off the pad with minimal damage to the pad.”

At the same time, he acknowledged that the launch hurled debris over a wide area, creating clouds of dust that reached a small town miles away from the launch pad on the southern tip of Texas.

During the nearly hour-long discussion on Twitter, Mr Musk answered offbeat technical questions and provided a detailed timeline of what went wrong during the four-minute flight.

Three of the spacecraft’s 33 booster stage engines were shut down before the rocket even left the launch pad.

“The system didn’t think they were healthy enough to push them to full capacity,” Mr. Musk said, “so they were shut down.”

The loss of the three engines caused Starship to pitch sideways on the way up. “We don’t typically expect lean,” Musk said. “Actually, it should go straight.”

Twenty-seven seconds after liftoff, something went wrong with one of the engines — “some kind of energetic event,” Mr Musk said — and it damaged several other engines nearby.

“But the rocket kept going,” said Mr. Musk. It was 85 seconds into flight “where things really hit the fan,” Mr Musk said, as the missile lost its ability to control its direction by pointing at the engine nozzles.

From that point, the missile began to fly out of control and continued even after the termination command.

“It took far too long to pop the tanks,” Mr Musk said of the flight cancellation system designed to destroy a runaway missile. The delay demonstrated the resilience of the missile, which remained intact when it fell.

“The vehicle’s structural margins appear to be better than we anticipated,” said Mr. Musk.

More explosives could be added for the next launch to ensure “the missile will detonate immediately if the flight needs to be terminated,” he said.

The other unexpected surprise was the shattering of concrete under the rocket on launch.

Thrust from 30 engines unexpectedly created a “rock tornado” that scattered debris across hundreds of acres and created a huge cloud of dust.

“Basically a man-made sandstorm,” said Mr. Musk. “But we don’t want to do that again.”

A large water-cooled steel plate is installed in place of the rocket’s 33 engines, which fire directly at the concrete beneath the rocket during launch. Mr Musk said the plate wasn’t ready for launch last week.

He said the next rocket and repairs to the launch pad would be ready in six to eight weeks. However, the Federal Aviation Administration, which regulates rocket launches, is investigating the events of the first launch and will have to settle for SpaceX’s adjustments and improvements before allowing another Starship flight.

The next launch would attempt to achieve the objectives of the first mission – that the Starship craft successfully detach from the booster and reach space before orbiting most of the planet and landing in the waters off Hawaii.

Mr. Musk did not promise complete success on the second attempt. He said he expects four or five more Starship launches this year. “We probably have an 80 percent chance of reaching orbit this year,” Mr. Musk said. “I don’t want to tempt fate, but I think the chance of reaching orbit within 12 months is close to 100 percent.”

Mr. Musk said SpaceX is spending “about $2 billion” on Starship this year and would not require additional investment to develop the rocket.

One of Starship’s main uses will be as a lunar lander during NASA’s Artemis III mission, which aims to take astronauts to the lunar surface near the South Pole. Mr Musk confidently assured Starship would be ready before other components like the Space Launch System rocket being built by NASA. “We’re not going to be a limiting factor at all,” he said.

He also highlighted the engineering challenges SpaceX is trying to overcome by producing a huge spacecraft that can be repeatedly and rapidly flown around, somewhat like a jet plane.

“This is certainly a candidate for the most difficult engineering problem solved by humans,” said Mr. Musk.