[feature request] Preview of future passes on map view

[ryandzink]

What might be a cool feature would be some kind of preview on the map view of where a future satellite pass footprint will cover, with some kind of draggable progress bar slider so you could see where the footprint is on various points of the pass. You can somewhat estimate what a satellite's coverage will be on a pass but higher orbit vs. lower orbit etc means that some kind of preview would be fantastic!