A simple addition methinks. It should be simple, holding Alt+ pressing backwards on the slow down time acceleration button should stop time. You should still be able to move the camera around and such, and input shouldn't start until after time is started again. Even a simple slowing effect would suffice for such a purpose. Now what is the actual benefit of this? Stopping time to think about things and get things started at the same time without action groups, going out of the tab whilst still remaining watching the rocket, and for just plain being cool.