Cosmic rays: space’s silent killer

How are these high-energy particles damaging astronauts’ bodies?

Brain damage

Studies in small mammals exposed to space radiation suggest changes to memory, inflammation of the brain, shape of brain cells, and an affect on the production of new cells.

Cataracts

Several Apollo astronauts reported seeing light flashes, likely caused by heavy ion interactions with the retinal photoreceptors in the eye as cosmic ray nuclei penetrates their head and eyes. They are at higher risk of cataracts too.

Cancer

Ionising radiation can cause cancerous mutations at 50mSv (millisieverts) and above, yet astronauts are exposed to approximately 50–2,000 mSv on a six-month mission.

Cardiovascular disease (CVD)

Studies on astronauts that have returned from their missions have shown that the amount of CVD-related deaths is much higher. Astronauts who have flown to the Moon are four to five times more likely to die from CVD than those who have never left Earth’s atmosphere.