(This topic is in reference of @Dex Luther's Orbital Miner: http://forum.micdoodle8.com/index.php?threads/orbital-miner.2604/) Space station dimensions could work like the Nether, one per primary planet (e.g. Overworld, Mars, Venus) and could be used to travel long distances in some kind of low orbit height, but the distances traveled in a Space station dim would be 1:1 ratio to the Overworld. This idea would allow the player to install or create space stations, satellites or any geo-synchronous equipments (e.g. the orbital miner) covering certain areas of the planet. (EDIT: And perhaps, to be able to travel from a space station to another and to satellites.) Currently, space stations (the structure) are always generated at 0,64,0; one per world in a separate dimension per player. In my idea, you could spawn more than one space station, anywhere in the space station dimension, referenced to the primary planet x/z-coords that you lift off from with your rocket. To avoid space stations overlapping each other, the space station dimension would be divided into "regions" of 512x64x512 (if you know how world saves work, you know it already). Each region fits in a 512x512 grid centered at 0,0; this mechanics is like the Map item. And the building limit would be 128 blocks for each direction, so that two space station will not touch or get too close to each other. For example, if you created a space station in the 0,0-region and want another, you have to travel 512 block along x or z axis for a free SS slot. If you fall from a space station located at 768, 768, you will fall at the same coord in the overworld.