Ask an Explainer
Does it matter how high the fins are on a rocket?
It does. The fins at the bottom of a rocket provide its stability. If the rocket starts tipping to the left, the pressure on the right side increases as the fins get pulled sideways through the air. This pushes the bottom of the rocket back to the left so it stays stable. The further down the rocket the fins are, the more leverage they have to make sure it flies straight. If the fins were at the top, the extra pressure on the right would push the top to the left, making it continue tipping and making the rocket unstable.