FAA Waives Hera Launch – Falcon 9 Remains Grounded

Falcon 9 currently finds itself in the midst of its third grounding in 2024. Following a successful launch of the Crew-9 mission and crew aboard Crew Dragon Freedom on September 28th, the Falcon 9 second stage experienced an anomaly during its deorbit burn, causing it to fall outside of the designated safe zone. No injuries or property damage has been reported, and any such damage is unlikely as the stage still landed within the ocean. Despite this, the issue with Falcon 9’s upper stage, the second such incident this year, presents notable concern and comes at an inopportune time.

The Crew-9 mission launched at 1:17 PM ET, and the upper stage engine ignited for the first time approximately two minutes and forty seconds into the flight. The stage’s Merlin Vacuum Engine (shortened as Mvac) completed a burn lasting six minutes and twenty seconds without any visible signs of error, safely placing Crew-9 into orbit, bound for the International Space Station. Every mission launched on Falcon 9 involves at least two upper stage burns, the final of which is a deorbit burn which sends the stage back down to Earth in a pre-designated oceanic disposal zone. After coverage on the upper stage had already concluded, the upper stage attempted its nominal disposal, but encountered an anomaly of unclear nature which resulted in it returning to Earth beyond the designated area.

The issue is reminiscent of Falcon 9’s July 11th launch failure which was also caused by upper stage irregularities. However, unlike this earlier incident, the engine showed no prior signs of misbehaviour, occurred outside of the publicly broadcasted portion of the flight, and did not result in a loss of mission. Space Scout emphasises that at this time there are no indications Crew-9 astronauts were in any danger during the launch. Additionally, had the launch environment become dangerous, aborts are exercisable by Crew Dragon that mitigate potential risk. The exact nature of the failure and the cause behind it remain unclear having not been publicly disclosed at time of writing.

Several hours after launch of the Crew-9 mission, at 12:20 the following morning, SpaceX officially recognized the failure on X, formerly Twitter. After a brief non-specific explanation of the anomaly, SpaceX’s post officially stated “we will resume launching after we better understand root cause.” This marked the beginning of Falcon 9’s third launch stand down of the year. The incident occurring on the weekend meant that the FAA did not release a statement until Monday, September 30th. The Monday afternoon statement affirmed that the agency was requiring an investigation. On October 1st, in an interview with Spaceflight Now Project Manager for ESA’s Hera mission, Ian Carnelli, indicated that a probable cause had been identified for the failure and communicated with Falcon 9 customers. Carnelli also stated that a report to the FAA would be submitted as soon as the end of the week–however, a week since the interview this report has not yet been submitted.

The primary concern facing Falcon 9 is timing. The September 28th incident preceded two time-sensitive launch windows by less than two weeks. The launch of ESA’s Hera mission, the follow-up to NASA’s DART, on October 7th, and the launch of NASA’s highly anticipated Europa Clipper, which has been delayed from its October 10th day due to impacts by Hurricane Milton. Both missions require the nominal and precise completion of two burns from Falcon 9’s upper stage to place them onto the correct interplanetary trajectories.

Ultimately, in order to proceed with the launch of ESA’s Hera spacecraft, the FAA had to issue a one time waiver on the basis that Falcon 9’s upper stage would not be returning to Earth, and therefore the risk posed by the Crew-9 mishap was not applicable. For emphasis: propulsion anomalies in isolation do not warrant an investigation or grounding by the FAA. As an example, ULA’s second Vulcan-Centaur rocket experienced its own anomaly last week. In this case, the FAA did not require an investigation, likely due to the relatively minor impact of the issue on Vulcan-Centaur’s mission and the lack of debris falling beyond the designated exclusion zone. It is likely that Europa Clipper will be allowed to launch via a similar waiver should the investigation remain open once weather provides a launch opportunity.

Hera launched successfully on the morning of October 7th 2024, and is now en route to asteroid 65803 Didymos and its companion Dimorphos.

So when can we expect to see Falcon 9 return to flight in full? There are, for better or worse, two recent groundings of the vehicle to compare against in lue of certain answers.

The latest preceding incident on Falcon 9 occurred on the night of August 28th, when the booster fleet leader, B1062, crashed upon landing following the launch of Starlink Group 8-6. The grounding which resulted from the incident was the shortest in the vehicle’s history, with Falcon 9 returning to operation on the morning of August 31st, a turnaround time under 72 hours. This was enabled by a finding of no public safety impact. This latest grounding has already exceeded a full week at time of writing, and is now Falcon 9’s second longest standdown of 2024. 

Several comparisons to the Starlink Group 9-3 anomaly have already been made, but reviewing the return to flight timeline may yield additional clues. Starlink Group 9-3 launched on July 11th; five days later, on July 15th, SpaceX submitted a request to the FAA to determine the public safety impact of the mission, expecting to return to flight on the grounds that Falcon 9’s upper stage did not threaten public safety. SpaceX submitted the results of their investigation into the root cause of the failure on July 25th, and shortly after that same day the FAA announced there was no threat to public safety as a result of the 9-3 incident. SpaceX returned Falcon 9 to flight two days later on July 27th. The total stand down time was just over two weeks.

Both prior incidents and subsequent returns to flight have been enabled by findings of no impact to public safety; both FAA-side investigations into these incidents remain open at the time of writing. Therefore it is most likely that the return to flight following Crew-9 will similarly rely on a finding of no public safety impact.

Questions raised by the seemingly sudden increase in unreliability for the Falcon 9 upper stage will likely remain unanswered, even after SpaceX submits reports on the specific cause of this latest failed burn to the FAA. Whether or not SpaceX is succumbing to the pressures of an ever-increasing cadence or other factors are at play behind the scenes remains in the realm of speculation.

SpaceX finds themselves entering a new era of their operation, one where their flagship Falcon 9 must learn to share a marketplace with new entrants all while carrying the bulk of American space access. The impact recent failures have on their record and ability to compete for and complete missions which lie ahead is uncertain. More than likely, however, Falcon 9 will see a relatively speedy return to flight following the safe launches of two highly anticipated planetary science missions this October.

Edited by Beverly Casillas and Nik Alexander