The overwhelming reality of space is that it is, for us, for the foreseeable future and perhaps forever, utterly lifeless, bleak, and empty. Nor do we have the ability to make it otherwise, except on paper or on the television screen. We live in the world where we arose, completely suited by God, evolution, or both, to its conditions. Unless we abuse it terribly, it keeps us alive even if we forget about it or ignore it. When our created systems malfunction, as they always do sooner or later, the earth is still there to hold us and keep us while we tinker with our broken creations. In space, when the rockets misfire, when the O rings and backup O rings fail, when the captain loses his mind, or when the waste-purifying algae develop a disease, as they all must sooner or later, then the story is over. If we could create a truly complete life support system to sustain us in space, then we would have created the earth.
--David Ehrenfeld, "The Lesson of the Tower"