Development of space motion sickness in a ground-based human centrifuge.

Adaptation of the vestibular system, specifically the otolith organs, to a non-terrestrial environment can result in space motion sickness-like symptoms when the human is reintroduced to the normal, 1 Gz, terrestrial environment. This premise was investigated by exposing nine subjects to 90 min of sustained 2 Gz acceleration in a human centrifuge and then observing and evaluating them at 1 Gz. Five of the subjects developed slight SMS symptoms, three developed moderate, and one developed frank sickness. Postural instabilities in two of the most affected subjects were also observed using the Equitest System post exposure. Long duration exposure to a non-terrestrial G(2Gz) appears to be a potential means for developing SMS-like symptoms in a ground-based human centrifuge.