Space travel revolves around the answers to three major questions that have confronted explorers for thousands of years: 1) Where will we go? 2) What will we do when we get there? 3) How will it benefit folks back home? Far beyond the technological issue of how to actually travel in space is the very practical issue of answering these questions long before we turn the first screw in the hardware, or the first plank in a ship's hull is layed. This...