SpaceX gave an update on what caused the loss of the Starship upper stage during test flight 7 last month.
"Two minutes into its burn, a flash was observed in the aft section of the vehicle near one of the Raptor vacuum engines; Sensors in the attic detected a pressure rise indicative of a leak after the flash was seen.
"Roughly two minutes later, another flash was observed followed by sustained fires in the attic. These eventually caused all but one of Starship’s engines to execute controlled shut down sequences and ultimately led to a loss of communication with the ship
"Telemetry from the vehicle was last received just over eight minutes and 20 seconds into flight.
"Contact with Starship was lost prior to triggering any destruct rules for its Autonomous Flight Safety System, which was fully healthy when communication was lost. The vehicle was observed to break apart approximately three minutes after loss of contact during descent. Post-flight analysis indicates that the safety system did trigger autonomously, and breakup occurred within Flight Termination System expectations.
"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.
"All debris came down within the pre-planned Debris Response Area, and there were no hazardous materials present in the debris and no significant impacts expected to occur to marine species or water quality.
"SpaceX reached out immediately to the government of Turks and Caicos and the United Kingdom to coordinate recovery and cleanup efforts. While an early end to the flight test is never a desired outcome, the measures put in place ahead of launch demonstrated their ability to keep the public safe."
