On and Off Planet, Paul Levinson, 2003, The Survival Imperative: Using Space to Protect Earth, William E. Burrows, 22 August 2006, Space (also called Hyperspace), BBC documentary narrated by Sam Neill, 2001 (BBC web site) The Case for Space: How the Revolution in Spaceflight Opens Up a Future of Limitless Possibility by Robert Zubrin, Prometheus Books (2019) External links Spaceflight or Extinction Academics and other leaders explain that we should colonize space to improve our chance of survival. Authors include Stephen Hawking and Carl Sagan. Alliance to Rescue Civilization Non-government organization founded by William E. Burrows, Robert Shapiro and others Back up civilization Robert Shapiro's response to Edge's hypothetical request from the American President: "What are the pressing scientific issues for the nation and the world, and what is your advice on how I can begin to deal with them?" Colonies in space may be only hope, says Stephen Hawking Sagan's rationale for human spaceflight Article about Carl Sagan and human spaceflight Survival Survival