Sickening space travel

摘要

JAKE GARN is a US politician who served as a Republican senator from 1974 to 1993. However, he seems doomed to be remembered not for any political achievements but for an unwitting contribution to the study of motion sickness in astronauts. Space motion sickness occurs because changes in gravitational forces affect spatial orientation. Physiological processes in which the human balance system plays a part need time to adapt to weightlessness. Until adaptation is complete, generally after two to four days, space travellers can experience nausea, visual illusions and disorientation.