This reviewed and accpeted project on the International Space Station is an integrative study protocol to provide a more holistic approach to become more conscious of and to increase the knowledge on the complex physiological adaptation of humans during long-term space missions. Adequate function of the human organisms in space is challenged by psychological/biological (e.g., confinement, sleep, pain) and physical stress factors (e.g., µG, variable oxygenation status, radiation). As a result, the immune system is targeted by a multitude of hormones, hormone-like substances as well as radiation effects, leading altogether to an imbalance of immune functions which can result in diseases. Further, confinement and other stressors can affect cognitive and emotional functions and may even cause affective problems, which, in turn, can negatively impact immunity. Moreover, in a multi- directional way, also infections and inflammation are stress events that interfere with other physiological systems as described in Figure 1.
The outcome hereof might be of importance in the light of future lunar or interplanetary missions: the understanding of the complex interactions of cognition, stress and immunity might as well suggest suitable countermeasures for the prevention of the unwanted immunological effects during space mission, but may also help to prevent from health risk by defining the individual risk factors