SpaceX Explains Falcon 9 Issue That Led to Temporary Grounding of Rocket Fleet
SpaceX is gearing up to resume operations of its Falcon 9 rocket after a brief hiatus following an incident involving one of its boosters. The booster, identified as B1086, caught fire and exploded shortly after a successful landing on a droneship during the Starlink 12-20 mission on March 2, 2025. Now, SpaceX is planning two launches, one from California and another from Florida, contingent on favorable weather conditions.
The last Falcon 9 launch took place over a week ago, which involved sending 21 Starlink satellites into low Earth orbit. During press conferences held recently regarding upcoming NASA missions, SpaceX officials provided insights into the cause of the incident involving B1086. Bill Gerstenmaier, who oversees Build and Flight Reliability at SpaceX, explained that approximately 85 seconds into the mission, a fuel leak occurred in the first stage of booster B1086. This leak caused kerosene to spray onto a hot engine part. While this didn’t ignite during the ascent due to insufficient oxygen, post-landing conditions allowed a fire to start roughly 45 seconds after the booster touched down.
Gerstenmaier noted that the fire managed to ignite in the engine compartment and eventually caused the barrel panel on the side of the rocket to blow off, which was the design’s intent to contain any fire. He reassured that even if there had been a problem during the ascent, the damage would have been localized to one engine, allowing the mission to be successful.
SpaceX is currently investigating the cause of the fuel leak. Gerstenmaier pointed out the challenges in distinguishing the cause from the subsequent effects of the fire. When the droneship returned to Port Canaveral, the engine section of the booster was removed for detailed examination.
In addition to SpaceX’s assessments, NASA and its Launch Services Program (LSP) conducted their evaluations of the Starlink incident. Julianna Scheiman, who heads NASA’s Science Missions at SpaceX, indicated that both organizations reviewed the launch data to ensure safety for future missions. Denton Gibson, the launch director for LSP, emphasized their independent assessment to mitigate potential risks.
The Federal Aviation Administration (FAA) has also been involved in this matter, conducting its investigation into the Falcon 9 fleet and temporarily grounding it. However, they approved the return of operational flights just a couple of days after the incident on March 4.
NASA is responsible for overseeing the launches of future missions, including the Crew-10 mission and the SPHEREx and PUNCH missions, and it retains the final authority on launch readiness.
Aside from the incident involving B1086, Gerstenmaier discussed another challenge from the Starlink 11-4 mission, which took place on February 1. A small oxygen leak led to issues with the second stage’s thrust vector control, causing loss of attitude control. Thankfully, despite this, the Starlink satellites were successfully deployed. However, the rocket’s second stage was unable to perform a deorbit burn as planned, eventually reentering over Poland.
Gerstenmaier clarified that for Crew Dragon missions, the duration limits minimize concerns related to such freezing issues. As a precaution, they are implementing additional checks and tighter margins regarding oxygen leaks on the second stage. This will also be verified in a static fire test scheduled for the Falcon 9 rocket intended for the Crew-10 mission.
The FAA didn’t ground the Falcon 9 fleet due to the incident from the Starlink 11-4 mission, but debris from its upper stage did fall to Earth, landing in Poland without any reported injuries. A similar issue happened during the Crew-9 mission in September 2024, which led to grounding the fleet temporarily due to an inability to perform a deorbit burn. SpaceX continuously evaluates and improves its processes and protocols to ensure the safety and reliability of its missions.
