Human exploratory missions to Mars represent the most exciting future vision of human space flight. With respect to the distance to travel and mission duration, these missions will provide unique psychological challenges that do not compare to any other endeavor humans ever have attempted. The present paper presents outcomes of two recent projects sponsored by the European Space Agency--Humex and Reglisse--where these challenges and risks have been analyzed in some detail, and where concepts for future research have been developed. This presentation involves three steps. At first, it will be shown that our current psychological knowledge derived from orbital spaceflight and analogue environments is not sufficient to assess the specific risks of mission into outer space. Secondly, new psychological challenges of missions to Mars will be identified with respect to three different areas: (1) individual adaptation and performance, (2) crew interactions, and (3) concept and methods of psychological countermeasures. Finally, different options and issues of preparatory psychological research will be discussed.
c2003 International Astronautical Federation. Published by Elsevier Ltd. All rights reserved.