Make: Rockets

Chapter 7. Rocket Stability

Remember the first balloon flight from Chapter 1? The balloon flipped crazily in the air, using most of its energy to twirl itself around. Imagine what that would be like with a model rocket. As soon as it left the launch rod, an unstable rocket would start to fly like the balloon, careening around in random directions, perhaps running into a spectator or flopping onto the ground with the motor still burning. It’s a good thing we build models from lightweight, collapsible materials and test them for stability before flying the rocket, because an unstable rocket can be pretty scary. Fortunately, rocket instability is easy to avoid once you understand what makes a rocket stable.

We’re going to look at several ways to see ...