Q: Is it possible to obtain the minimum GM of the jacket during a launch simulation?
REV 5.06

A: GM is a measure of stability and stability only makes sense with respect to a "singular point" of the equations of motion (an equilibrium position or a constant velocity state). During launch, there is acceleration and hence, GM would not be useful here.

I think that the reason you are interested in GM is to see what happens if the jacket stops during the launch. If this is the case, you can: move the jacket to a position, find equilibrium, and then see how stable it is.