Space Station Expansion Pack part 1

With the establishment of the Entity 2 space station, an expansion comes to mind for future bases on Mun and Minmus. I plan on adding a mining base on Mun while having a manned research base established on Minmus, and that means there has to be a way to transport large amounts of materials and equipment between the three bodies. This means I have to utilize the space tug; a vehicle capable of docking and moving large heavy objects with little fuel to keep fuel requiremens at a minimum and to save time. Since tugs are generally very heavy, a large rocket is used. Here the tug is boosting itself up to a higher orbit so it will be properly positioned to dock and move payloads. Note the dual nuclear engines for the highest possible efficiency without sacrificing power.

The next load is the space station Unity's docking module. Since Unity was too heavy to launch on the Delta 1 rocket, but would be too light to launched on the Delta 3, it was launched in two segments and assembled in orbit.

 Then the command section of the station, the section that is able to move on its own via RCS thrusters and reaction wheels, is boosted up on the same Delta 1 rocket as the docking section. It contains a medium sized mover tug that can attach to payloads and then move them to re-arrange the station or add more sections if needed. The mover tug serves the same purpose as the assembler on Entity, but is unmanned thanks to the new reaction wheel system.

 Since the command module of the Unity station is probe-controlled, it is able to maneuver itself to dock with the docking module of the station.

Now, with the space station complete, it is time for the tug, named Kopernicus, to boost the station into a higher orbit. This is so that trips to and from the two moons will take less delta-v, while still within reach of tanker ships from Kerbal Space Center to refuel the shuttle and tugs. This space station will also feature two more sister stations one each of the moons to form a transportation network using these three stations, or the Unity Triplets, allowing for fuel and kerbal transfers at centralized locations throughout the Kerbin system.

Currently, all of the tugs in use have both senior and regular docking ports, allowing for tugging of heavy loads and of small, light payloads that are too small or too light to need the senior docking port. These payloads are usually expansion parts for each individual space station, such as a small Kethane converter and tank, a couple of hitchhiker storage pods for kerbals, or even aesthetic touches such as a communications antenna or a science package.

With the station now in orbit, the unmanned tug now burns back into its parking orbit of 180 km to wait for its next load.