The prevention of motion sickness in orbital flight

A question has arisen whether zero gravity qualifies as just another "motion environment" in which motion sickness may be elicited, or if one or more undetermined etiological factors are present which render such terms as "motion environment" and "motion sickness" inappropriate. The question is of more than academic interest for the reason that in the forthcoming Shuttle Program we have either one problem or two: one if we are concerned solely with prevention, but two if we must tackle the problem of covert etiological factors as well. This problem points up the need to define motion sickness if investigators, world-wide, hope to resolve the matter in the most economical manner. Meanwhile, substantial reliance must be placed on the use of antimotion sickness drugs and some recent findings are presented based on tests carried out in a rotating room using a new procedure. Whereas previous findings in our laboratory dealt with group responses, the new findings are not only valid for a group, but also valid for each subject tested. It was demonstrated that the effects of a drug may be efficacious for a group yet may be detrimental for one or more individuals in that group.