So off to Mars we go. But really how are we going to get there? The most expensive part of space travel is overcoming atmosphere. So you could say the biggest obstacle of space travel is Earth travel. It takes virtually no energy to cross space but it takes massive amounts to get into space. It's kind of like walking to the bus stop. It may take a lot of my energy to get to the stop but once there I have to spend very little energy. So my though is that we build a bus stop in space. We send many rockets from earth to this space bus station and from there a "mothership" departs for Mars. Now this mothership doesn't need much energy to travel as tthere is no resistance in space. The primary concern will be life support and artificial Gravity. I suggest using a very simple spiral design that uses a sort of photovoltaic cloth that spirals around the core of the ship. This cloth is also reflective thus creating a solar sail. Due to the spiral shape thi will create a form of both propulsion and Gravity this eliminating two key energy hogs. As I mentioned this cloth would also be photovoltaic and create energy "on the fly." The bigger the sails the more energy can be given to thrust and the quicker we can get people to Mars. So that parts easy. The question we really have to focus on is how to overcome atmosphere. Well first why not shorten the distance? Instead of launching at sea level why not launch from a summit?! Second, since the trip will only be to a near earth bus station you could forgo all extras needed for a long journey. What do you guys/gals think?