The exploration and colonisation of Mars, as discussed in the more than 130 papers and essays from the Mars Society's annual conferences, is presented in this second volume of the On to Mars series. Covering recent technological and planning advances, these essays cover the last three years of Mars Society meetings and discuss such topics as habitat infrastructure, exploration technique, and colony organisation as they have been explored at the Mars Society's Analogue Research Stations at Devon Island, Nunavuit in Canada and in Hanksville, Utah. Two short videos, Stepping Stones to Mars and Robert Zubrin's testimony before the Senate Committee on Commerce at the Hearings on the Future of the U.S. Space Program, are featured on the included CD-ROM.