The Tu Wien Space Team have released their preliminary findings on what caused the failure of the sustainer ignition of their “The Hound” rocket. The Rocket was launched at Balls 2018 and was intended to break the current European student and amateur rocketry record.
The fault came down to the team’s onboard electronic module, STARM (Space Team Arming Device). The module is designed to keep the sustainer system safe while the rocket is on the ground, hence prevent motor ignition. The system only sends an open channel command for the igniter when liftoff is detected by an accelerometer. Unfortunately, the module was not wired up correctly and therefore did not detect liftoff, thus not opening the command channel required for sustainer ignition.
The full write up is worth a read with a lot more flight analysis and plans to move forward, read it here.