Currently, paper-based and/or electronic together with telecommunications links to Earth-based physicians are used to assist astronaut crews perform diagnosis and treatment of medical conditions during space travel. However, these have limitations, especially during long duration missions in which telecommunications to earth-based physicians can be delayed. We describe an experimental technology called GuideView in which clinical guidelines are presented in a structured, interactive, multi-modal format and, in each step, clinical instructions are provided simultaneously in voice, text, pictures video or animations. An example application of the system to diagnosis and treatment of space Decompression Sickness is presented. Astronauts performing space walks from the International Space Station are at risk for decompression sickness because the atmospheric pressure of the Extra-vehicular Activity space- suit is significantly less that that of the interior of the Station.