I am a fledgling undergrad with a potential mechanical engineering degree in my future. I just have a hypothetical question about the space elevator that yall may be able to help me with. I have not taken my physics courses yet so forgive my limited working knowledge of the material. If you can make reference to any math you use, let me know and I will study it on my own to better understand. If you have a space elevator with required x height, how long would it have to be in order for the climbing car to begin to travel up/outward due to the inertia of the spinning earth. I know that you would have to overcome gravity. Would the tether be so long that you couldn't use the inertia as a method of moving the payload? Could you use the tether as a guide for a blimp or weather balloon until the balloon reached a maximum altitude and then propel (using rocket or mechanical device) the payload until the inertia took over?