I've had no thoughts on a Mars mission for some time, but after watching the documentary on Mars One (which is think is not an option specifically to go to Mars and not return), I began going through feasibility scenarios and came to the following conclusion:
The critical element in the journey for humans is the journey itself, i.e the ability to keep humans healthy and safe for the approximately 180 day journey. Let's call a vehicle capable of this caretaking "the bus". My thought is that a mission should place one or possibly two of these "buses" on a permanent shuttling trajectory between Mars and Earth - and probably two due to the irregularity of orbits. It/they would never stop - they would just constantly slingshot between the two planets.
The bus needs three things: a human or humans for the "trip", the fuel and food for the ride, and the means to get them "off the bus" and onto the target planet. All of that needs to "catch" the bus, which might be a tricky thing given its speed at the catching point of either planet.
My question is whether this has any flaws in approach - the equipment and setup on the bus seems to need to be durable - and if there are any plans similar to this outlined at any URL.