[sandworm101]

Shuttle was held on the launch pad after ignition for a couple seconds because of flex. The stack initially flexed out of alignment when the main engines were lit, the stack being asymetrical. Only once the nose drifted back to vertical would the srbs ignite and the stack begin to move.

[hermitcrab]

OpenRocket is intended for amateur rocketry, not NASA space shuttles.

Amateur rocketry people try very hard to make their rockets symmetrical.

Hobby rockets have to be stiff enough not to banana. I don't think it is figured into model rocketry beyond that.