WASHINGTON — A Falcon 9 booster that was destroyed after landing March 2 suffered a fuel leak during its flight that triggered a fire.
SpaceX officials speaking at two briefings March 7 about upcoming launches for NASA provided new details about the incident on the March 2 launch of a set of Starlink satellites, known by the company as Group 12-20, which caused the booster to topple after landing on a droneship.
At one briefing about the upcoming Falcon 9 launch of NASA’s SPHEREx astronomy spacecraft and PUNCH space science mission, Julianna Scheiman, director of NASA science missions at SpaceX, said a fire broke out about 48 seconds after what appeared to be a normal landing of the booster.
“That fire eventually resulted in the deterioration of the structural integrity of the landing leg in that booster and toppled over,” she said.
Scheiman said both SpaceX and NASA’s Launch Services Program (LSP) reviewed data from the incident. “There’s no concern or risk to ascent.”
Denton Gibson, launch director for the mission for NASA LSP, confirmed at the briefing that NASA did its own independent evaluation of the incident, offering a “fresh set of eyes” to ensure there are no issues with the upcoming launch. “We’ve gone through that process and we’ve gotten comfortable,” he said, allowing the completion of a launch readiness review.
The SPHEREx/PUNCH launch, now scheduled for 10:09 p.m. Eastern March 8, has been delayed more than a week primarily by launch vehicle issues. While SpaceX has not conducted a Falcon 9 launch since the failed landing, Scheiman said teams have been working on other issues with the vehicle for SPHEREx and PUNCH, including the payload adapter and fairing.
At another briefing a few hours later about the Crew-10 mission to the International Space Station, Bill Gerstenmaier, vice president of build and flight reliability at SpaceX, offered more details about the incident on the Group 12-20 launch.
He said there was a fuel leak starting about 85 seconds after liftoff in one of the nine engines in the booster. The fuel was vaporized by a hot portion the engine, creating a flammable environment. “But on the way up, there was on oxygen to interact with the fuel, so there was no problem at all during ascent.”
He said that about 45 seconds after landing, “enough oxygen came into the compartment where it interacted with the fuel and a hot portion of the engine, which was known to be hot, and then we had a fire.” That fire blew out a “barrel panel” on the side of the rocket as designed. The fire, he noted, was contained within the compartment for that single engine.
“If we would have a problem during the ascent, this shows that the fire and the damage would be contained with just a single engine out, which still allows us to accomplish the entire mission,” Gerstenmaier said.
Engineers are still working to identify the source of the leak. “It’s pretty difficult to determine what was cause and what was effect from the fire,” he said. “The fire was pretty extensive. It melted a lot of aluminum components, so it’s difficult to see.”
Steve Stich, NASA commercial crew program manager, said later in the briefing that the agency will look carefully at that issue as it prepares for the Crew-10 launch, scheduled for March 12. That includes a static fire of the booster planned for the evening of March 9.
“We have an opportunity to step back and think about our flight, and think about the maintenance we did on our vehicle, all the areas that we inspected,” he said. “We’ll go static fire the vehicle and look extra careful to look see if there’s any area where we could potentially have a fuel leak.”
