One of the things I like to do in KSP is attempt to create or recreate proposed, real-world space missions with the tools and Mods I have available in KSP.

One of my  more recent mission creations was based around the Mars One Mission plan that calls for a base to be remotely deployed to Mars, with a follow-on crew of 4.  The total mission time is approximately 500 days, and makes use of the NASA Proposed, Deep Space Habitat Module.

The Deep Space Habitat is based around unflown Space Station Hardware, notably, Node 4, and MPLM based modules for logistics, life support and habitation.

For this mission recreation I've decided to make use of Umbra Space Industries OKS/MKS Modular Colonization System for the Duna base station, Fustek Station Parts which are visually based on the US ISS Modules, and I'll be using the LazTex SpaceX Packs for Launch Vehicles, and the Dragon v2 as the crew vehicle and lander/ascent vehicle.

The mission will consist of several stages.

Phase 1 the launch and assembly of the Duna Colony in Kerbin Orbit, and it's transit and landing to Duna.  Phase 1 will also include The launch, transit and landing of a robotic rover on the Duna surface to survey a suitable landing site for the Colony.  The Colony Lander will remain in Duna orbit until a suitable location is located.

Phase 2 will launch a SpaceX Dragon Cargo ship carrying supplies for the Kerbalnaut's stay on Duna. This vehicle will wait in Duna orbit for the arrival of the crew and will land at the colony site once they arrive.

Phase 3 will see the assembly of the Deep Space Habitat in Kerbin Orbit.

Phase 4 will launch the crew in a SpaceX Dragon v2 with the Lander Trunk, which will dock with the Deep Space Habitat and be carried to Duna to act as the descent/ascent vehicle for the Kerbalnauts.

Phase 5 will consist of the science mission on Duna waiting for the transfer window for return to Kerbin to open.

Phase 6 will consist of the Crew returning to the Deep Space Habitat waiting for them in Orbit for the transit back to Kerbin Space.  They crew will then make their final descent aboard the same SpaceX Dragon v2 vehicle.