They have the Spaceport on Ranov, so they can attack spaceport-adjacent spaces on other planets.

However:

However, in order to attack any special quadrant (i.e. space port, hive city, city, manufactorum, etc.), the players faction will be required to first hold at least one quadrant which is adjacent to the target first.
So, can't do a space attack except to an empty space adjacent the spaceport?