nantly empirical and generally successful approach to these matters. The research and development requirement, however, for evidence-based coordination between design engineering, habitability considerations, and behavioral health imperatives assumes ever-increasing importance with extended mission durations. Under the closed-loop conditions of such missions, for example, all waste products (including human excretions, expired gases, fluids, etc.) must be repeatedly recycled. The unique behavioral health factors involved in the toleration and acceptance of such environmental constraints must be investigated and determined. The extent to which behavioral self-management techniques (Beck and Emery, 1985; Beck, 1993; Barlow, 1996; Cautela and Ishaq, 1996) can be expected to provide effective coping procedures for such intrapersonal challenges will depend on the development and testing of individualized self-monitoring and self-assessment methodologies of demonstrated validity and reliability.
Perhaps the matter of highest priority in the performance and general living conditions domain is the development of an evidence-based approach to the management of harmonious and productive, small, multinational groups who must live and work together in isolated, confined, and hazardous environments. Although an extensive literature on the functioning of small groups in both analog environments (Helmreich, 1973; Gunderson, 1974a,b; Vinograd, 1974; Palinkas, 1990; Harrison et al., 1991; Taylor, 1991; Weybrew, 1991; Palinkas et al., 1995; Stuster, 1996) and experimental settings (McGrath and Altman, 1966; Emurian et al., 1981; Brady, 1990; Brady and Anderson, 1991; Duffy, 1993; Guerin, 1994; McGrath, 1997) has been generated over the past half century, the available knowledge base is deficient with respect to long-duration missions beyond Earth orbit in several ways. For example, findings from group studies conducted in one setting are often not applicable to groups functioning under other environmental conditions. Empirical results are typically of such limited scope that they lack practical utility and generalizability.
The conditions under which such experimental observations or even observations from analog environments are made usually differ considerably from those encountered in operational spaceflight situations. The benefits and disadvantages of traditional approaches to the study of small-group dynamics have been well documented. When observations of the behaviors of small groups are made when the groups are in their natural habitat or in an