Overnight, SpaceX announced that it had experienced an anomaly with the Falcon 9 second stage used to launch Crew 9 on September 28, and that it was grounding the vehicle while it investigated the issue:

At the time of this writing, the Federal Administration Administration (FAA) has not commented on this matter, or whether it would formally withhold launch licensing from Falcon 9 while SpaceX completed its investigation.

Crew 9 Proceeding As Planned

Notably, this incident occurred after Commander Nick Hague and Mission Specialist Alexsandr Gurbonov had separated from the second stage, and beforehand, the stage had provided a nominal orbital insertion for them aboard Crew Dragon and Crew 9. That mission continues with a planned docking at ISS sometime around 5:30 PM EDT today.

So What Happened?

SpaceX’s announcement was sparse on details, however the problem was explained well by Dr. Jonathon McDowell of the Harvard–Smithsonian Center for Astrophysics.

McDowell said X.com earlier this morning that the Falcon 9 second stage used yesterday did not deorbit as planned and probably came down east of New Zealand sometime overnight:

So where did the Crew-9 second stage come down?
Here is the ground track of Crew-9 based on the TLE (orange) and the planned stage 2 deorbit area (white rectangle) pic.twitter.com/gBFlY2f9dJ

— Jonathan McDowell (@planet4589) September 29, 2024

McDowell, who meticulously maintains a list of all launches and other space events, added on X.com, “The most likely failure mode that still results in reentry is a slight underburn (less delta-V, higher resulting perigee). If you underburn too much the perigee will be too high for reentry to occur. So you expect the entry to be further along the orange line but not by too much.”

He added in a successive post, “Here is the ground track showing the planned reentry area at bottom left. My analysis suggests that an off nominal deorbit that still ends up with stage reentry will impact on the orange line somewhere between the end of the white rectangle and the equator.”

Practical Effects

SpaceX is known to complete its investigations quickly, and if it is not restricted from launching by the FAA, one can expect them to investigate and remediate the problems with the Falcon 9 second stages with alacrity. The chances, however, of the FAA requiring a formal investigation and safety determination seems high if the immediate past is any guideline.

It is notable that this is the second major incident this year for a Falcon 9 second stage, with the first being on July 11th when a Starlink launch went awry due to a Merlin Vacuum engine failure. The FAA required SpaceX to make a public safety determination prior to returning to flight, a process that took fifteen days.

SpaceX also had a first stage landing failure in August, which resulted in the FAA requiring SpaceX to make a second public safety determination prior to launching again Falcon 9. That took only three days.

It’s unknown if yesterday’s issue and the one on July 11th are related in any way, and any conjecture that they are is just guesswork at this point. Short of SpaceX announcing that there is any relationship between the Jully 11 issue and the one this morning on September 29, no one knows one exists. That said, it is a second problem in 2024 with the second stage of the venerable Falcon 9.

The FAA has yet to make any public comments regarding today’s SpaceX announcement, but it would not be surprising if they were to formally require a new public safety determination for the incident SpaceX described this morning.

Practical Effects

SpaceX has multiple launches upcoming on its immediate manifest, including the Europa Clipper on Falcon Heavy, which is planned to fly NET October 10 from LC-39A at Kennedy Space Center. They also have the HERA mission scheduled for NET October 7, a mission for OneWeb NET October 1st and a few Starlink mission interspersed in between. As always, SpaceX is busy.

Those launch dates are reasonably in question as a result of the Crew 9 issue, as all are within a fifteen-day window of time, if using the July 2024 Falcon 9 second stage issue is any guideline.

None of that is set in stone, however, and this is a very fluid situation on Sunday, September 29th.

Stay tuned.