"Spaceports have doubled in cost to 2400 BP but can now be moved by freighters. They are equal to four research facilities for transport purposes (or 80 factories). They retain their existing bonuses to loading and unloading cargo."
"A ship can only refuel at a Spaceport, a Refuelling Station, a ship with a Refuelling System or a base with a Refuelling Hub."
"In addition, Box launchers can only be reloaded in a hangar, or at an Ordnance Transfer Point (a Spaceport, Ordnance Transfer Station or Ordnance Transfer Hub)."
"A ship can only receive ordnance at a Spaceport, an Ordnance Transfer Station, a ship with a Ordnance Transfer System, a base with a Ordnance Transfer Hub or in a military hangar bay."
"Space Stations can be built by construction factories at any population that includes a Spaceport."
". . . a freighter or colony ship cannot load / unload unless it has at least one Cargo Shuttle Bay, or the target population has either a Spaceport or a Cargo Shuttle Station (new installation, 1200 BP)."
"For C# Aurora, box launchers can only be reloaded in a hangar, or at an Ordnance Transfer Point (a Spaceport, Ordnance Transfer Station or Ordnance Transfer Hub)."
"A ship can only resupply at a population with a spaceport, a cargo shuttle station or at least one maintenance facility, or from a ship with cargo shuttles."
"Conventional Start
. . .The player now receives:
. . .
Spaceport
. . . "
"Installations without Required Tech
. . .The full list of the installations that can be constructed before Trans-Newtonian Theory is researched is as follows:
. . .
Spaceport
. . ."
- - - - -
In other words, a Spaceport is a ground-based 'everything' station that combines all other logistics functions (possibly at a space and/or cost savings, depending on how many of those functions one actually needs).