Comments
All motor components were recovered. O-Ring had clearly failed, leading to aft closure thread failure as well as critical damage to the casing. Once the aft closure failed, the motor casing broke free of the thrust ring and separated the rocket. The motor itself was ejected out of the top of the rocket's booster section and landed a few feet from the pad. The aft closure and nozzle were retained by the motor mount. There was approximately 1" of burn damage (beginning aft) to the inside fiberglass of the motor mount, and the delay grain did not burn through - the ejection charge did not fire. The attached image shows the burn-through damage to the aft closure. The O-ring also cleanly burned through and lines up with the burn damage to the closure and the threads (the damaged portion of the O-ring is rotated to the right and barely visible in the attached photo; I unfortunately don't have a photo of everything lined up). It's clear from the condition of the aft closure threads that they stripped out once exposed to combustion gases, allowing the motor and casing to accelerate forward up the booster section. Video of the launch shows the motor casing clearly flying out of the top of the the booster section, extinguished. Both the limited amount of damage to fiberglass in the motor mount and the video of the motor casing ejecting from the booster section indicate that the motor immediately burnt out once pressure was lost.
