Falcon 9 upper stage leaks liquid oxygen on Starlink 9-3, stranding satellites in a low orbit; FAA grounds the rocket

SpaceX/Falcon 9 & Falcon Heavy

On the Starlink 9-3 launch on July 11, 2024, from Vandenberg Space Force Base, Falcon 9's upper stage sprang a liquid oxygen leak, preventing its orbit-raising burn. The 20 Starlink v2 Mini satellites were deployed too low (~135 km perigee) and re-entered within about a day. The leak was traced to a cracked sense line on the oxygen pressure sensor due to vibration fatigue and loose clamp. The FAA grounded the rocket pending mishap investigation.

• Launch: July 11, 2024, from Vandenberg Space Force Base.
• Upper-stage failure: liquid oxygen leaked from cracked sense line on pressure sensor.
• Root cause: vibration fatigue + clamp looseness; ice buildup visible on engine during broadcast.
• Payload: 20 Starlink v2 Mini satellites (13 with Direct-to-Cell); all thought lost to premature reentry.
• FAA grounded Falcon 9 pending investigation; later cleared for return to flight (no public safety risk found).