Regulators have given SpaceX the green light to return to launch with its Falcon 9 rocket two weeks after the vehicle suffered an in-orbit malfunction.
It was a quick turnaround for the space company, which had to conduct an investigation under the auspices of the Federal Aviation Administration, determine the likely cause of the anomaly, and what corrective actions it would take to ensure it didn’t happen again. This course of action is standard after a rocket launch gone wrong.
SpaceX’s Falcon 9 rocket experienced a rare in-orbit problem after a routine launch of a batch of Starlink satellites on July 11. While the launch and stage separation went as expected, the second stage experienced a catastrophic problem. Twenty satellites were deployed, but they were in too low an orbit to survive. All of the satellites reentered the atmosphere and burned up.
Late Thursday, SpaceX confirmed in an update posted on its website that The problem was caused by a leak of liquid oxygen in the insulation surrounding the single Merlin engine in the second stage. This leak was due to a crack in the sensor line connected to the pressure sensor, which had developed due to a loose clamp in the line and stress from engine vibration.
Despite the leak that occurred during the first second-stage engine’s in-orbit firing, the mission continued to operate normally. But the liquid oxygen made the engine components extremely cold; as a result, the second attempt to fire the engine did not go as planned. Instead of a controlled burn, the engine “experienced a hard start,” SpaceX said, damaging the engine and causing the upper stage to lose its orientation in orbit.
SpaceX said it removed the faulty sensor line and sensor on the Falcon 9’s second-stage engine for near-miss launches, which are not used in the flight safety system. The company has already tested the design change at its McGregor, Texas, rocket development facility. SpaceX added in its update that the company has also conducted additional inspections of all sensor lines on its active second-stage fleet, leading to “preemptive replacement” in some cases.
Prior to that number, SpaceX boasted 335 Falcon rocket launches, including 96 successful launches in 2023 and 69 successful launches this year.
While the FAA said in a statement that a full investigation remains open, SpaceX said it has submitted an accident report to the regulator.
“After a comprehensive review, the FAA has determined that there were no public safety issues from the anomaly that occurred during the July 11 launch of SpaceX Starlink Group 9-3,” the regulator said in a statement to TechCrunch. “This public safety determination means that the Falcon 9 spacecraft can return to flight operations while the full investigation remains open, provided all other licensing requirements are met.”
SpaceX plans to launch its new Falcon 9 rocket on July 27. That launch will carry another batch of Starlink satellites into orbit.