Swap the false and true in the script and the rocket will function like intended
Video:
body.freezeRotation = true;
transform.Rotate(Vector3.forward * rotateThisFrame * Time.deltaTime);
body.freezeRotation = false;
Fix:
body.freezeRotation = false;
transform.Rotate(Vector3.forward * rotateThisFrame * Time.deltaTime);
body.freezeRotation = true;