STRESSORS, STRESS AND STRESS CONSEQUENCES DURING LONG-DURATION MANNEDSPACE MISSIONS - A DESCRIPTIVE MODEL

Keeping crew members in good health is a major factor in the success o r failure of long-duration manned space missions. Among the many possi ble agents that can affect the crew's general well-being, stress is ce rtainly one of the most critical because of its implications on human health and performance, both physical and mental. Nevertheless, very f ew studies have been performed on this fundamental issue and none of t hem has addressed it in its entirity, considering its diverse physical and psychological aspects. In this work, a descriptive model is propo sed to expound the mechanism and sequence of events which mediate stre ss. A critical analysis of the information provided by past manned spa ceflights and by dedicated research performed in analogous environment s is presented, and an extrapolation of the available data on human st ress in such extreme conditions is proposed. Both internal and externa l stressors have been identified, at physical and psychosocial levels, thus providing the basis for their early detection and preventive red uction. The possible negative consequences of stress that may lead to disease in crewmembers are described. Finally, the most effective Inst ruments which may be of help in reducing space-related human stress an d treating its negative consequences are suggested.