However, the rate of SANS has not dropped as engineers have got better at scrubbing CO2 from the ISS’s air. Smith suspects that SANS involves an interplay of CO2, vitamin deficiency and genetics.

However, the rate of SANS has not dropped as engineers have got better at scrubbing CO 2 from the ISS’s air. Smith suspects that SANS involves an interplay of CO 2 , vitamin deficiency and genetics.

Ongoing research. As for its cause, SANS is tied to the absence of gravity's effects on the body, causing a fluid shift that can generate pressure changes in the brain and eye. This fluid shift is ...