During a SpaceX livestream, ice could be seen accumulating on the Falcon 9’s engine following its launch from California’s Vandenberg Space Force Base en route to releasing 20 Starlink satellites. According to SpaceX, this buildup of ice caused a liquid oxygen leak. Then part of the engine failed, and the rocket dropped several satellites into a lower orbit than intended, one in which they could readily fall back into Earth’s atmosphere.
By July 12, an FAA press statement was circulating on X. The federal agency said it was aware of the malfunction and would require an investigation. “A return to flight is based on the FAA determining that any system, process, or procedure related to the mishap does not affect public safety,” said the statement.
SpaceX says it will cooperate with the investigation. “SpaceX will perform a full investigation in coordination with the FAA, determine root cause, and make corrective actions to ensure the success of future missions,” says a statement on the company’s website. Details about what the investigation will entail and how long it might take are unknown. In the meantime, SpaceX has requested to keep flying the Falcon 9 while the investigation takes place. “The FAA is reviewing the request and will be guided by safety at every step of the process,” said the agency in a statement.
Nominal failure
The Falcon 9 has an unusually clean safety record. It’s been launched more than 300 times since its maiden voyage in 2010 and has rarely failed. In 2020, the rocket was the first to launch under NASA’s Commercial Crew Program, which was designed to build the US’s commercial capacity for taking people, including astronauts, into orbit.
According to MIT aerospace engineer Paulo Lozano, part of the Falcon 9’s success is due to advances in rocket engines. Exactly how SpaceX incorporates these new technologies is unclear, and Lozano notes that SpaceX is quite secretive about the manufacturing process. But it is known that SpaceX uses additive manufacturing to build some engine components. This makes it possible to create parts with complex geometries (for example, hollow—and thus lighter-weight—turbine blades) that enhance performance. And, according to Lozano, artificial intelligence has made diagnosing engine health faster and more accurate. Parts of the rocket are also reusable, which keeps costs low.
With such a successful track record, the Falcon 9 malfunction might seem surprising. But, Lozano says, anomalies are to be expected when it comes to rocket engines. That’s because they operate in harsh environments where they’re subjected to extreme temperatures and pressures. This makes it difficult for engineers to manufacture a rocket as reliable as a commercial airplane.
“These engines produce more power than small cities, and they work in stressful conditions,” says Lozano. “It’s very hard to contain them.”
What exactly went wrong last week remains a mystery. Still, experts agree the event can’t be brushed off. “‘Oh, it was a fluke’ is not, in the modern space industry, an acceptable answer,” says McDowell. What he finds most surprising is that the malfunction didn’t occur in one of the reusable parts of the rocket (like the booster), but instead in a part known as the second stage, which SpaceX switches out each time the rocket launches.