SpaceX explains how the Falcon 9 bits hit Poland
SpaceX has published an explanation for the debris from the Falcon 9 second stage that fell over Poland last week. Because of an oxygen leak, the expected deorbit burn didn’t occur.
The second stage that came down was from a mission launched on February 1 to deploy another 22 Starlink satellites into low-Earth orbit. While the landing of the first stage was a success, the deorbit burn of the second stage did not occur. On February 19, the stage made an uncontrolled entry over Poland, lighting up the sky and depositing debris in the country.
There were no injuries or substantial property damage, but this was more down to luck than good judgment.
The incident marks the third time in since July last year that a SpaceX Falcon 9 upper-stage did not perform as planned, although only one of these situations resulted in a loss of mission. In that first case, on July 7th 2024, 20 Starlink satellites were left stranded in a lower-than-planned orbit after a liquid oxygen leak prevented the upper stage from performing a circularization burn. In September last year, an issue with the second stage deorbit burn resulted in a deorbit burn that sent debris to the wrong part of the ocean.
According to an update on SpaceX’s page for the February 1 mission, another liquid oxygen leak was to blame for this malfunction as well, although it occured after the Starlink satellites had been deployed. The second stage’s engine would usually be relit to send it into an ocean area. However, during the coast phase, an oxygen leak developed “which ultimately drove higher than expected vehicle body rates.”
Rather than risk lighting the engine, SpaceX engineers opted to “passivate” the vehicle – usually venting all propellant and discharging the batteries so there is nothing onboard to cause the stage to break up while in orbit – and allow it to reenter uncontrolled unexpectedly.
The company said there were no toxic materials in the debris that fell over Poland last week, but advised anyone coming across bits of the second stage to leave it alone and contact authorities. It said it “is working closely with the government of Poland on recovery and cleanup efforts.”
While three incidents in just over seven months might seem a lot, it is also worth considering the rate at which SpaceX is launching Falcon 9 rockets. There have been 10 launches so far in February alone.
However, although the first stage of the rocket is designed to be reused, SpaceX must manufacture a new second stage for every launch.
SpaceX said, “The teams are actively assessing root cause of the source of the leak and have already implemented mitigations for future flights.” It did not go into detail about what those mitigations might be.
As the pace of launches increases for SpaceX’s workhorse Falcon 9, the upper stage issues are a sign of strain beginning to show in the company’s operations. ®
