Playing devil's advocate here, I say we just push through and go to Mars. Human history is full of biting off challenges bigger than we can chew, but we always find a way to make it happen. From building the great pyramids to the invasion of Normandy, humans can conquer even the most insurmountable feat. Look what we did in a few short years in the 1960s with rudimentary computers and a limited knowledge of space -- we landed on the Moon in the first place.
Granted, the motivation needs to be present, we need to stay on task. It took us 66 years to go from the first fixed-wing flight to the success of the Apollo missions. In the following 40 years, we've made only limited advancements in aeronautics. However, when we put a challenge in front of courageous individuals, we can change human history.
What Mars has waiting for us and exactly how we'll get there is unimportant. The glory of taking on that challenge and prevailing is the reward. As far as space exploration, Mars is our Mount Suribachi. We need to put the American flag (and the flags of the world) on the highest ridge on a foreign planet -- proudly and successfully, no matter the cost. Only then will we be victorious.
And then we look to Europa...