Astronaut and blogger Ron Garan is coming home after nearly six months in space. Reflecting on his preparation for his trip, he writes: “As I prepared to leave for final launch preparations, I experienced an interesting phenomenon. Realizing that leaving Houston starts me on a journey that will take me off the planet for six months, I started to take note of things that I will not experience for half a year. Whether it’s a flock of birds against the sunset or early morning mist on the water of Clear Lake, or a million other things that define the beauty...