Big ups to the MIT Rocket Team team for posting this and sharing their experience. We can all learn from this, but most importantly no one was hurt or injured. A testament to having good safety protocols in place.
Looking forward to seeing the issues resolved, and future testing carried out.
Video Caption: At T+ 2.9s a combination of insufficient grease, poor polyurethane application, and inconsistent assembly technique lead to a catastrophic burn through of the thermal liner in the middle of grain 4.
The motor self extinguished at the catastrophic loss of pressure, but the propellant which remained in the motor reignited several seconds later due to residual heat.
This test did not endanger any people. Always use care when testing rockets.