Couple of weird gotchas here.  `location_size` is a bit unwieldy; it seems that if I ask for a location's size I should be able to do it with `location.size`.  I would say the same for location_type, except that "type" is a Rails keyword.  Depending on what we want to represent, maybe this becomes "category", "nature", or "kind".  Spaceport_size is fine for now, as stand-in data, but if we decide we're going to go down the spaceport road we might need to create a first-class Spaceport object - that is, unless we decide that a Location has exactly one spaceport, and the absolute only thing we care about is its size, such that the spaceport size is truly a property of the location.