The primarects of the study called ISEMSI (“Isolation Study for European Manned Space Infrastructure”) was the psychological research, with the double aim of collectinuable know-how, and gathering and organizing a community of researchers oriented towards specific space related psychological issues. Six EMSInauts (members of the ISEMSI crew) were locked up in NUTEC's hyperbaric chamber facility an overpressure equivalent to 5 meters depth for a period of 4 weeks. The psychological experiments showed that simple performance, such as reaction time and vigilance, were unaffected during the isolation. However, the more complicated mental strategies showed some temporal changes throughout the 28 days. The perceived workload indicated that the overall load was emotionally, cognitively and physically in the middle range, even though the actual working hours were up to 12 hours. The load did not give any effects either on symptomatology, or on endocrinology and heartrate variability. Regarding group interaction, the commander developed more control during the isolation period. This gave increased negative responses towards him from the rest of the team. There was also an overall increase in emotional content during the isolation period (negative feelings/frustrations). There were, however, few communication problems with ground control.