Cato Cam 2017/04/29

Rockets are hard. Even when you’ve checked every joint, tightened every screw, and re-rolled your parachute 3 times something can still go wrong. During the same launch as my level one cert flight, there was a catastrophic failure in a different rocket. Just as it was coming off the launch pad, it burst apart into multiple pieces. I happened to be taking photos at the time and got 3 shots of the result. If we look at the first photo we can see three blobs, the nose cone (on top), the parachute (in the middle and colored red) and the body tube (bottom covered in smoke and we can still see the flames). Looking closely we can also see the cord tying all three pieces together.

In the second picture, we can see the nosecone and the parachute falling to earth, while the body of the rocket continues upwards.

What I think went wrong.

From these two picture, I would guess that the delay between the motor and the ejection charge was either drilled out or there was a manufacturing error causing it to fail less than one second into flight. This set off the ejection charge, which caused the rocket to separate into multiple pieces without exploding. Failures are common enough in rocketry that the shorthand has been developed. They are simply called catos. Having one of your rockets cato is always disheartening, but you can often learn a lot about your rocket, and systems in general, though analyzing failures.