Falcon 9 Grounded after Anomaly

At 7:30 Pacific Standard Time on July 11th, 2024, a Falcon 9 Block 5 rocket carrying the Starlink Group 9-3 satellites lifted off from Vandenberg Space Force Base. Following successful stage separation and ignition of the upper stage’s vacuum-optimised Merlin (Mvac) engine, a substantial build up of ice was observed. The ice accumulated upon the upper stage engine’s Mylar covering, seemingly tearing it at one point. The Falcon 9 first stage landed nominally, and SpaceX’s coverage of the mission ended with second stage engine cutoff at T+8:45. After coverage ended, an additional orbit-raising burn from Mvac and the deployment of the Starlink satellites were expected. Over an hour after confirmation of payload deployment was expected, SpaceX CEO and Founder Elon Musk took to the website formerly known as Twitter with the statement: “Upper stage restart to raise perigee resulted in an engine RUD (Rapid Unscheduled Disassembly, SpaceX-speak for explosion) for reasons currently unknown. Team is reviewing data tonight to understand root cause.” In the same post, Musk stated that some Starlink satellites were deployed, but in a significantly lower orbit than intended, and were all at risk of falling back to Earth.

This represents the first failure of the Falcon 9 system since it exploded on the pad back in 2016 ahead of the AMOS-6 mission, and the first in-flight failure since CRS-7 in 2015. In follow-up posts, Musk stated Starlink Group 9-3 satellites that had regained contact with the ground were given software patches to run their ion engines at higher-than-usual-thrust in an attempt to escape atmospheric drag, though noted “this will probably not work.” Around 10:30 AM the following morning, the FAA made a statement to outlet NASASpaceflight in response to an inquiry, confirming that the agency was aware of the failure and was requiring an investigation into its cause before Falcon 9 can return to flight – grounding the United States’ most utilized launch vehicle.

Falcon 9 is a critically important component in the ecosystem of American spaceflight, and the pressure will be on to get through the investigation and return Falcon 9 to flight quickly. However, Falcon 9 regularly carries sensitive payloads and human astronauts, and for these reasons the investigation can not be rushed either. Between all of the compounding factors, only time will tell when Falcon 9 will be permitted to fly again.

What is known is Falcon 9’s flight manifest at the time of last night’s failure, and from this it is possible to derive potential impacts depending on the amount of time Falcon 9 remains grounded. Should Falcon 9 remain grounded through the end of July, this would delay two commercial satellite missions, several Starlink launches, and SpaceX’s Polaris Dawn mission; the company’s second free-flying private astronaut mission, and first with an EVA. 

If the delay continues through the first week of August, the NG-21 mission to the International Space Station, the second flight of Northrop Grumman’s Cygnus spacecraft aboard Falcon 9, will be delayed. If this occurs, there is precedent to move Cygnus onto a similarly capable rocket, such as ULA’s Atlas V, to maintain cadence should the return to flight be significantly delayed. However, there is currently a comfortable amount of consumables aboard the International Space Station, such a swap may not be necessary. Also planned to launch in August is the SpaceX Crew-9 mission, which would deliver four astronauts to the ISS as part of Expedition 72. While Boeing’s Starliner spacecraft continues its Crewed Flight Test aboard ISS, Boeing is not yet ready to scramble a spacecraft to take over the upcoming crew rotation slot.

September and October are critical months, and therefore it is likely that Falcon 9 will be pushed to return to flight earlier, sometime in August. In September, Crew Dragon Spacecraft Endeavour, which carried Crew-8 astronauts to the station back in March of 2024, will need to come home due to the limited on-orbit life span of its solar cells. The Soyuz’ spacecraft also currently on-station will need to return shortly after, though the launch of the next Soyuz in rotation, Soyuz MS-26, would be unaffected by Falcon 9 delays. Should Falcon 9 be unable to launch before Endeavour’s nominal on-orbit lifetime is exceeded, it could result in a breakage to permanent US Crew Vehicle presence aboard the orbiting laboratory. Thanks to seat trades with Russia, American Astronaut Don Pettit will fly to Station on MS-26, resulting in maintained American presence on-station. In October a Falcon Heavy rocket, which shares Falcon 9’s upper stage design, is expected to launch NASA’s Europa Clipper mission, similarly a Falcon 9 is scheduled to fly ESA’s Hera mission. Both missions utilize Mars gravity assists to reach their targets, and therefore both would experience delays potentially up to two-years should Falcon miss their windows.

This is all entirely speculative, no changes to Falcon 9’s schedule have been announced so far. Falcon 9 has completed over 300 successful launches, and remains critically important to the global launch market, therefore it is entirely likely that Falcon 9 returns to flight sooner rather than later.

Falcon 9 is currently experiencing its highest flight rate ever, with SpaceX aiming for a total launch count of 144 in 2024–a goal SpaceX was on track to meet. Even just pad SLC-4E which launched Starlink Group 9-3 was aiming to launch around 50 Falcon 9s in 2024, breaking the pad’s previous annual launch record of 28. There has been some discussion that pressure to maintain Falcon 9’s flight-rate may compromise the system’s safety, though whether or not the launch failure was directly tied to this pressure cannot be determined at this time.

With so many unknowns regarding Falcon 9 following this incident, the best those who follow spaceflight can do is simply wait for information regarding what comes next. Time will tell if Falcon 9 can return to flight quickly and continue its various responsibilities, or if the flaw runs deeper and will require significant effort to address.

UPDATE: In a statement posted to the website formerly known as Twitter, SpaceX confirmed a loss of the full mission stack, with the satellites encountering too much drag to successfully raise their orbits.

Edited by Emily B. and Nik Alexander