On July 11, SpaceX encountered a critical failure problem on one of its Falcon 9 rockets. The problem resulted in a Rapid Unscheduled Disassembly (RUD) protocol to be initiated, or boom.
SpaceX has taken to its website and X account to share an update on the review process following the failure of a Falcon 9 rocket. Notably, SpaceX's Falcon 9 is the company's workhorse rocket, having already launched 24 times this year and more than 350 times since its debut in 2010. During that time it has only experienced one catastrophic in-flight failure.
However, on July 11, a critical failure occurred during the first burn of Falcon 9's second-stage engine. SpaceX explains a liquid oxygen leak developed within the simulation around the upper stage engine, with engineers later discovering the cause of the leak was a crack in a sense line for a pressure sensor that's attached to the vehicle's oxygen system. The sense line cracked due to "high loading from engine vibration and looseness in the clamp that normally constrains the line."
The liquid oxygen leak resulted in engine components excessively cooling, particularly components associated with providing the engine with ignition fluid. This chain reaction caused the engine to have a "hard start" which caused damage to the engine hardware and ultimately lead to the rocket losing altitude.
SpaceX explains that it has worked with the Federal Aviation Administration (FAA) to implement the necessary changes to avoid a failure like this happening again.
"For near term Falcon launches, the failed sense line and sensor on the second stage engine will be removed. The sensor is not used by the flight safety system and can be covered by alternate sensors already present on the engine. The design change has been tested at SpaceX's rocket development facility in McGregor, Texas, with enhanced qualification analysis and oversight by the FAA and involvement from the SpaceX investigation team.
An additional qualification review, inspection, and scrub of all sense lines and clamps on the active booster fleet led to a proactive replacement in select locations," reads the SpaceX press release