One thing about the TOS Enterprise's Hangar Deck always nagged at me: we're given the impression that space efficiency aboard a starship is paramount, that there's only room for one launch bay, and that there are a limited number of shuttlecraft (either total shuttles stored on-board or total shuttles actually in active operation; take your pick) and yet there's that launch bay, with all that overhead space. We're on board a space vessel that employs artificial gravity. Why can't shuttlecraft be stored up above?
And remember that cargo bay we saw in the lower vortex of the refit saucer
in TMP? Why can't the saucer have room for at least one small launch bay? After all, the saucer is supposed to be able to separate, right? What good is the saucer if it separates and has no means of housing shuttelcraft, at least in a limited fashion?