“On my second space walk, I was riding the Canadarm, heading down toward the payload bay of the space shuttle, and I could see the space shuttle highlighted against the Earth in the background, and there was this black, infinite, hostile void of space. I remember looking down at the Earth and thinking, "Beneath me is a 4½-billion-year-old planet, upon which the entire history of the human species has taken place." That was an incredibly humbling moment, and I had a bit of an epiphany.”
