Why Does My FLIPing Rocket Always Flip Over!
AKA: Forces at Work During Launch and Ascent and How to Deal with Them.
Part 1:
A Stable Rocket
First let's take a look at a stable multi-stage rocket, like the one in this picture:
Notice that the Center of Mass is closer to the bottom than the top; that's normal. Also, notice that the fins are below the center of mass which helps with stability.
Take a look at what happens when the rocket is moving through the ai