The proceedings of STAIF-2006 features a broad spectrum of topics on: space nuclear power and thermal propulsion, science and technology; space exploration; space colonization; advanced propulsion concepts; advanced radioisotope power systems; thermophysics in microgravity; energy conversion technologies; nuclear fuel and high temperature materials; high power electric propulsion, heat pipes and capillary pumped loops and advanced radiators; nuclear reactor safety; simulation and modeling; space exploration, Lunar and Mars outposts; and advanced propulsion physics. These topics span the range from basic research to the most recent technology advances and hardware development and testing.