Given the near incomprehensible enormity of the universe, it appears almost inevitable that humankind will one day find a planet that appears to be much like the Earth. This discovery will no doubt reignite the lure of interplanetary travel. Will we be up to the task? And, given our limited resources, biological constraints, and the general hostility of space, what shape should we expect such expeditions to take?

Introduction : a false dichotomy -- The human/robot debate -- Human spaceflight as utopia -- Promoting the human dimension -- Robotic spaceflight in popular culture -- The new space race -- Interstellar flight and the human future in space -- Homo sapiens, transhumanism, and the postbiological universe -- An alternative paradigm? -- Appendix : Inadequate words.