President Bush at the Columbia memorial: “This cause of exploration and discovery is not an option we choose; it is a desire written in the human heart. We are that part of creation which seeks to understand all creation. We find the best among us, send them forth into unmapped darkness, and pray they will return. They go in peace for all mankind, and all mankind is in their debt. Yet, some explorers do not return. And the loss settles unfairly on a few.”