Overview
This was a ground test of the Hermes Pathfinder rocket. It occurred on Field A at 3:45 PM on November 10, 2017. It was the first use of the Pyrotechnic Piston to separate the rocket. The piston contained 1g of 4F black powder. The tender descender contained .2g of black powder. The rocket used 3x 6-32 nylon shear pins. The rocket successfully separated, and the tender descender released the main parachute appropriately. After de-integration it was found that the Avionics Bulkhead was seriously deformed. This prevented the planned flight on November 11, 2017 from occurring.
Failure Investigation
Solidworks FEA confirmed that the deformation is consistent with a 2-bolt load application. The magnitude of the deformation suggests that either the aluminum exhibits lower than expected mechanical properties after welding, or that the piston supplied significantly more force than anticipated.
Additional Analysis is underway.