Elon Musk: SpaceX’s uncontrolled starship struggled to self-destruct
During its brief first flight more than a week ago, the giant Starship rocket made by SpaceX generated an unexpected “rock tornado” at launch, and multiple engines failed as it headed upward before spiraling out of control.
Then, Elon Musk, the company’s founder, said in an update delivered 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 the Starship. Instead, 40 seconds passed before the rocket finally exploded.
Despite everything that went wrong, Mr. Musk considered the launch of Starship a success.
“Obviously not a complete success,” he said, “but successful nonetheless.”
He said the goal of the test flight was “to learn a lot, and we learned a lot,” and that more test flights were planned this year.
The spacecraft, the most powerful ever launched, is central to SpaceX’s goal of getting humans to Mars, as well as to NASA’s plans to return astronauts to the moon by 2025 as part of the Artemis program.
Although the rocket didn’t make it to space, “the result was about what I expected, and maybe a little bit above my expectations,” Musk said, noting that it got “clear of the pad with minimal damage to the pad.”
At the same time, he acknowledged that the launch threw debris over a large area and generated dust clouds, which reached a small town miles away from the launch pad on the southern tip of Texas.
During the discussion on Twitter, which lasted nearly an hour, Musk answered rough technical questions and provided a detailed timeline of what went wrong during the four-minute flight.
Three of the 33 engines on the Starship’s booster stage were shut down before the rocket even left the launch pad.
“The system didn’t think they were healthy enough to bring them to full thrust,” Mr. Musk said, “so they shut down.”
The loss of the three engines caused the Starship to lean to its side as it headed upwards. “We don’t normally expect a lean,” Mr. Musk said. “It should actually go right up.”
27 seconds after launch, something went wrong with one of the engines — “some kind of energetic event,” Musk said — and damaged several other nearby engines.
“However, the rocket continued,” Mr. Musk said. It was 85 seconds into the flight “where things really hit the fan,” Musk said, when the rocket lost its ability to control direction by pointing at the engine nozzles.
From that point the rocket began to fly out of control and continued even after the shutdown command.
“It took way too long to blow up the tanks,” Musk said of the flight termination system, which is meant to destroy an out-of-control rocket. The delay demonstrated the resilience of the rocket, which remained intact when it fell.
“The structural margins of the vehicle appear to be better than we expected,” Mr. Musk said.
For the next launch, more explosives may be added to ensure that “the rocket explodes immediately if it is necessary to terminate the flight,” he said.
The other unexpected surprise was the crushing of concrete under the rocket at launch.
The thrust of 30 engines unexpectedly generated a “rock tornado” that scattered debris over hundreds of hectares and generated a giant dust cloud.
“Basically a man-made sandstorm,” Mr. Musk said. “But we don’t want to do that again.”
Instead of the rocket’s 33 engines firing directly at the concrete below the rocket during launch, a large water-cooled steel plate will be installed. Mr Musk said the disc was not ready for last week’s launch.
He said the next rocket and the repair of the launch pad would be ready within 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 be satisfied with SpaceX’s adjustments and improvements before allowing another Starship flight.
The next launch would attempt to achieve the goals of the first mission – for the Starship vehicle to 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 full success on second attempts. He said he expected four or five more Starship launches this year. “We probably have an 80 percent probability of reaching orbit this year,” Musk said. “I don’t want to tempt fate, but I think almost 100 percent chance of reaching orbit within 12 months.”
Mr. Musk said SpaceX spent “$2 billion” on Starship this year and would not need additional investment for development of the rocket.
One of the main uses of the Starship will be as a lunar lander during NASA’s Artemis III mission, which is to take astronauts to the lunar surface near the south pole. Mr. Musk confidently asserted that Starship would be ready before other components such as the Space Launch System rocket are built by NASA. “We don’t want to be a limiting factor at all,” he said.
He also emphasized the technical challenges that SpaceX is trying to overcome in producing a giant spacecraft that can quickly be flown again several times, something more like a jet plane.
“This is certainly a candidate for the hardest engineering problem done by humans,” Musk said.
