A Space Colony works like a <l:6,104>city<e>, but it exists in Earth's orbit. Only <l:1,51>Space Engineers<e> can <l:6,48>build<e> a Space Colony. These orbital cities cannot build <l:2,20>Airports<e> or any pre-<l:6,131>Industrial Age<e> improvements. Only <l:1,65>Marines<e>, <l:1,55>Space Marines<e> and <l:1,60>Swarm<e> can unload into a Space Colony guarded by enemy units.