Space motion sickness: Skylab revisited
Graybiel, A.
Aviation Space and Environmental Medicine 51(8): 814-822
1980
ISSN/ISBN: 0095-6562 PMID: 7417150 Document Number: 161502
The etiology of symptoms characteristic of motion sickness experienced by some of the Skylab astronauts was reportedly due to the headward shifts of fluids which occurred after transition into orbit. The fluid-shift theory is questionable. Free fall apparently is a partial motion environment rendered complete by the execution of head movements. In Skylab the astronauts varied greatly in their susceptibility to motion sickness. Four were not sick; 5 were sick but only 2 vomited, each on one occasion. Soon after recovery, and without practice, all 5 were immune in a provocative test based on the generation of cross-coupled angular accelerations while they executed head movements during rotation up to 30 rpm. All had manifested symptoms in this test preflight. Free fall apparently is a motion environment in which many persons are immune and susceptible persons readily adapt. After achieving adaptation, all Skylab astronauts were highly insusceptible. Some difficulties in dealing with motion sickness under operational conditions are discussed and the limitations of antimotion sickness remedies are emphasized.