Really, really good book on this subject: http://en.wikipedia.org/wiki/The_Millennial_Project:_Colonizing_the_Galaxy_in_Eight_Easy_Steps http://en.wikipedia.org

Really, really good book on this subject: http://en.wikipedia.org/wiki/The_Millennial_Project:_Colonizing_the_Galaxy_in_Eight_Easy_Steps http://en.wikipedia.org/wiki/The_Millennial_Project:_Coloniz... http://www.amazon.com/Millennial-Project-Colonizing-Galaxy-Eight/dp/0316771635 http://www.amazon.com/Millennial-Project-Colonizing-Galaxy-E... The book does a nice job of capturing all the hard engineering problems. His proposed solutions are interesting but a bit superficial.