During its brief maiden flight more than a week ago, the giant Starship rocket made by SpaceX generated an unexpected “rock tornado” on launch, and several engines failed as it lifted before spiraling out of control.
Then, Elon Musk, the company’s founder, said in an update during a Twitter audio chat on Saturday night, the end of the flight was more exciting than it should have been. An automated self-destruct command did not immediately destroy Starship. Instead, 40 seconds passed before the rocket finally exploded.
Despite everything that went wrong, Mr. Musk’s launch of Starship a success.
“Obviously it’s not a complete success,” he said, “but successful nonetheless.”
He said the purpose of the test flight was “to learn a lot, and we learned a lot”, and more test flights were planned for this year.
The spacecraft, the most powerful ever launched, is central to SpaceX’s goals of getting humans to Mars, as well as NASA’s plans to return astronauts to the moon by 2025 as part of the Artemis program.
While the rocket didn’t make it to space, “the result was about what I expected, and maybe a little higher than my expectations,” Mr Musk said, noting that it “came clear of the path with minimal damage to the path” .
At the same time, he acknowledged that the launch debris hurled debris over a wide area and created clouds of dust, which reached a small town miles from the launch pad in the southernmost tip of Texas.
During the discussion on Twitter, which lasted nearly an hour, Mr. Musk asked obscure technical questions and gave a detailed timeline of what went wrong during the four-minute flight.
Three of the 33 engines on the Starship’s booster stage shut down before the rocket left the launch pad.
“The system didn’t think they were healthy enough to bring them up to full power,” Musk said, “so they shut them down.”
The loss of the three engines caused Starship to lean to the side as it lifted. “Normally, we don’t expect lean,” Musk said. “It should actually go straight up.”
Twenty-seven seconds into launch, something went wrong with one of the engines — “some kind of energetic event,” Musk said — and that damaged several other nearby engines.
“The missile, however, kept going,” Musk said. It was 85 seconds into the flight “where things really hit the fan,” said Mr. Musk, when the missile lost its ability to steer its direction by aiming the engine’s nozzles.
From that moment on, the missile started flying out of control and continued even after the termination command.
“It took way too long to destroy the tanks,” Musk said of the flight-termination system, which is intended to destroy a missile out of control. The deceleration demonstrated the missile’s resilience, which remained intact as it tumbled.
“Vehicle structural margins seem better than we expected,” Musk said.
More explosives could be added for the next launch to ensure that “the missile detonates immediately when the flight needs to be terminated,” he said.
The other unexpected surprise was the bursting of concrete under the rocket on launch.
The thrust of 30 engines unexpectedly created a “rock tornado” that spread debris over hundreds of acres and created a giant cloud of dust.
“Basically a man-made sandstorm,” Musk said. “But we don’t want to go through that again.”
Instead of the rocket’s 33 motors firing directly at the concrete under the rocket at launch, a large water-cooled steel plate is installed. Mr Musk said the record was not ready for last week’s launch.
He said the next rocket and launch pad repairs would be ready in six to eight weeks. However, the Federal Aviation Administration, which regulates rocket launches, is investigating the events of the initial launch and will have to be content with SpaceX’s tweaks and improvements before allowing another Starship flight.
The next launch would attempt to accomplish the goals of the first mission: The Starship vehicle would successfully detach from the booster and reach space before circling 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 expected four or five more Starship launches this year. “We probably have an 80 percent chance of getting into orbit this year,” Musk said. “I don’t want to tempt fate, but I think there’s almost a 100 percent chance of getting into orbit within 12 months.”
Mr Musk said SpaceX is spending “$2 billion” on Starship this year and will not need additional investment for the rocket’s development.
One of Starship’s main uses will be as a lunar lander on NASA’s Artemis III mission, to deliver astronauts to the lunar surface near the south pole. Mr. Musk confidently claimed that Starship would be ready before other components such as the Space Launch System rocket are built by NASA. “We won’t be a limiting factor at all,” he said.
He also highlighted the engineering challenges SpaceX is trying to overcome in producing a giant spacecraft that can quickly be reflown repeatedly, something like a jetliner.
“This is certainly a candidate for the most difficult engineering problem man-made,” Musk said.
