SpaceX

Highlights:

• Cause of engine-out during boostback: "a low-power condition in the igniter system. Raptor engines on upcoming flights have a pre-planned igniter upgrade to mitigate this issue."
• S33 FTS did trigger: "Post-flight analysis indicates that the safety system did trigger autonomously, and breakup occurred within Flight Termination System expectations."
• Cause of S33 failure: "The most probable root cause for the loss of ship was identified as a harmonic response several times stronger in flight than had been seen during testing, which led to increased stress on hardware in the propulsion system. The subsequent propellant leaks exceeded the venting capability of the ship’s attic area and resulted in sustained fires."
• "Findings from [S34's 60-second] static fire informed hardware changes to the fuel feedlines to vacuum engines, adjustments to propellant temperatures, and a new operating thrust target that will be used on the upcoming flight test."
• They also beefed up the ship fire suppression systems... again.