In my idea, i'd demolish HISTA and the present outdoor que area(the roof of HISTA). Now that there is room I'll tell you my idea on how to plus the line for Space Mountian...
you know how you have to go upstairs to reach the indoor line? and how people don't like the current sloped walkway to get there? No problem anymore with HISTA out of the way we can make a new out door line with a more easy to spot eterance. Instead of a sloped walkway or an escalator to get upstairs you'll be taken upstairs by an elevator. You heard that right, an ELEVATOR. You must be asking your self "why not just make an escalator?". The elevator would not seem to be an elevator though. It would be a Giant elevator in the style of The Haunted mansion's Streching room. You would enter thinking that you just came into Space Mountian. Inside it would be a well themed room with a giant TV screen and It turns on and tells you that you have just entered Space Mountian and that you're about to depart from from the Tomorrowland Space Port into space. There's some kind of Mission control sounding voice that says "Space Mountian ready for departure from Tommorowland Space Port" and you feel the Elevator rise making it feel like Space mountian just hovered out of Tomorrowland. after that the doors open and you continue on to the upstairs portion of the line and into the ride.
so what did you think?
what would you do to improve Space mountians line?