Methods: To evaluate these issues, we studied 5 American astronauts, 8 Russian cosmonauts, and 42 American and 16 Russian mission control personnel who participated in the Shuttle/Mir space program. Subjects completed questions from the Profile of Mood States, the Group Environment Scale, and the Work Environment Scale on a weekly basis during the missions. Subscale scores from these measures were analyzed using a piecewise linear regression approach that analyzed normally distributed subscales using a mixed model and non-normally distributed subscales by dichotomizing the variables and using a generalized estimating equation.
Results: After protecting against possible Type I errors due to multiple significance tests, only weak support was found for the biphasic model: the only significant findings in favor of the hypothesized 2nd half decrements in the interpersonal environment were in crewmember GES Leader Support and astronaut WES Work Pressure. Strongly consistent confirmation was found on all 6 tested measures for the hypothesized displacement of tension and dysphoria from crewmembers to mission control personnel. The hypothesized displacement of tension and dysphoria from mission control personnel to management was found on 5 of the 6 tested measures.
Conclusions: The absence of moderate to strong support for the biphasic model suggests that crewmember interpersonal functioning does not depend appreciably on 1st half/2nd half time effects. The consistent support found for the displacement of tension and dysphoria suggests that countermeasures need to be developed to deal with this phenomenon in both crewmembers and mission control personnel.