Getting the Inertia Tensor Right!

Jay Estes, a friend of mine has done a great job making the explanation of how to use the inertia tensor in your equations of motion. The key is to remember that inertias are often calculated and reported in the structural frame. However, you often compute dynamics in a body frame. The X38 example below show the typical situation that needs to be accounted for in the setting up of a dynamic simulation of a airplane or spacecraft. Here is an excerpt from his discussion.