This answer is best illustrated by describing the sound that occurs the moment a model rocket takes flight. The sound of a model rocket motor igniting is a “whoosh” rather than a “bang”. Why is this important? The simple difference in sound belies an important construction difference between model rocket motors and pyrotechnic fireworks.

Fireworks are designed to produce a “flash” or sharp retort (or both). The energy produced by a firework travels in all directions outward thus the unit cannot be held without fear of injury. In addition the charge (powder in most cases) is consumed at once. This effect is often what people are referring to when they ask about “explosions”. A model rocket motor is designed to harness the force of ignition by allowing the charge ( a hard powder composite) to steadily burn from the back to the front of the motor body. This provides a directed thrust that powers the rocket into flight. Thus the telltale “whoosh” that is associated with model rocket ignition.

Explosions on the pad? Maybe in the latest summer blockbuster movie but not in the real world of model rocketry! The worst case scenario for any rocketeer is a rocket that binds on the launch rod and is prevented from lifting off. In this case the motor will ignite, the rocket will stay put (often the secondary charge will pop off the nosecone and deploy the parachute) and the rocketeer will be forced to retrieve his or her rocket to gales of laughter and applause.

Another important difference is can be found in the method of ignition. Fireworks are lit with a fuse. Model rocket motors - by design - must be lit with a special igniter made to work only with the small electrical charge provided by a launch controller (typically in the neighborhood of 6-9 volts). This charge provides a small but significantly hot source of ignition within the motor itself - far higher in temperature than can be achieved by applying a match or lighter. In early tests, rocket motors were exposed to all sorts of ignition sources; open flame, torches, even bonfires. None of these sources created enough heat to ignite the motors themselves..