Maintenance of complex performance during a 135-day spaceflight simulation.

BACKGROUND The maintenance of crew performance during extended space missions has been a major concern because of the problems associated with prolonged isolation and confinement. Previous research has failed to address this problem by not using appropriate performance tests. METHOD Three Russian cosmonauts were tested on a PC-based simulation of a spacecraft's life support system during a 135-d simulation of a MIR spaceflight. A complex multiple-task environment was used to examine a comprehensive range of task management variables, including both primary and secondary task performance, control activity and information sampling behavior. Subjective state variables were also measured. RESULTS The data suggested an overall successful adjustment to isolation and confinement, though some indications of temporary disruptions of some performance indicators were observed. Information sources were sampled less frequently with increasing mission length while system control activities showed a tendency to increase. CONCLUSION Suggestions are made to address the problem of continuous learning during repeated testing sessions. Using well-designed computer simulations of complex task environments appears to be a promising approach for the evaluation of crew member performance.