Space motion sickness and motion sickness: symptoms and etiology.

The adverse symptoms of space motion sickness (SMS) have remained problematic since the beginning of manned spaceflight. Despite over 50 yr of research SMS remains a problem that affects about half of all space travelers during the first 24-72 h of a spaceflight. SMS has been treated as another form of motion sickness (MS) despite distinct differences in symptomology.

A rationale for space motion sickness.

Space motion sickness (SMS) still remains a problematic nuisance for a majority of fliers during their first 1 to 3 days in space and is an enigma to all concerned after almost half a century of spaceflight and extensive ground and in-flight studies. There is no known etiology consistent with observed signs and symptoms, and attempts to produce pre- and in-flight countermeasures have largely failed. Some medications for motion sickness (MS) have been partially effective, but must be used with caution due to their side effects.