We Don’t Know Why Astronauts Get Motion Sick

Space motion sickness (SMS) affects many astronauts, causing symptoms like nausea and dizziness. Despite long-standing awareness, the exact cause remains unclear. Three main hypotheses are explored: fluid shift, sensory conflict, and otolith asymmetry. Fluid shift suggests microgravity redistributes body fluids, affecting the vestibular system. Sensory conflict posits mismatched sensory signals cause SMS. Otolith asymmetry considers ear stone size differences. Ongoing research, including private space missions, aims to better understand and mitigate SMS.

What percentage of astronauts report experiencing some degree of Space Motion Sickness?

• 10-30%

• 30-50%

• 60-90%

• 90-100%

What does the fluid shift hypothesis suggest about the effects of microgravity on the body?

• It increases bone density.

• It redistributes body fluids, affecting the vestibular system.

• It causes muscle atrophy.

• It enhances cognitive functions.

Why might early astronauts have reported fewer symptoms of SMS according to the sensory conflict hypothesis?

• They had better training.

• Their missions were shorter.

• They were mostly stationary during flights.

• They had superior equipment.

What is the main idea behind the sensory conflict hypothesis?

• Microgravity affects blood circulation.

• Mismatched sensory signals cause confusion.

• Spacecraft vibrations induce nausea.

• Lack of sleep leads to dizziness.

What does the otolith asymmetry hypothesis propose?

• All astronauts have symmetrical otoliths.

• Astronauts with larger ear stones are less likely to experience SMS.

• Asymmetry in ear stones may increase susceptibility to SMS.

• Otoliths are unaffected by microgravity.

What is the purpose of the Polaris Dawn mission related to SMS research?

• To explore Mars.

• To conduct experiments on otolith asymmetry.

• To improve spacecraft speed.

• To test new space suits.

What is a potential downside of using medications to treat SMS symptoms?

• They are too expensive.

• They cause drowsiness.

• They require special storage.

• They are ineffective.