How does space travel affect astronaut health?

Space travel poses numerous physiological challenges, including radiation exposure, bone density loss, and psychological stress for astronauts.

The human body was not built for spaceflight, with its microgravity conditions, exposure to high-energy radiation and other issues. As a result, trekking beyond the the earth’s confines causes many physiological changes that affect an astronaut’s health.

Here is an explanation of some of the effects on human health caused by space travel.

The human body evolved over millions of years to function optimally in the earth’s environment, which includes its gravity, atmospheric composition and relatively low levels of radiation.

Space travel exposes people to quite a different environment, posing a range of physiological and psychological challenges, especially with prolonged exposure, according to Afshin Beheshti, director of the Center for Space Biomedicine at the University of Pittsburgh.

As researchers seek new countermeasures to protect space travellers, more data is needed on astronauts with varying health backgrounds and undertaking different kinds of missions in order to map out personalised risk profiles and mitigation strategies, according to Chris Mason, a professor of physiology and biophysics at Weill Cornell Medicine in New York.

Unlike on the earth, where the atmosphere and planetary magnetic field provide a shield from space radiation, astronauts are exposed to high-energy radiation permeating the cosmos. This can lead to DNA damage, increased cancer risk, neurodegenerative effects, cardiovascular issues and immune system dysregulation.

The earth’s magnetosphere - the region of space dominated by the planetary magnetic field - provides some protection for astronauts in missions in low-earth orbit. But astronauts traveling beyond that - such as on missions to the moon or Mars - would experience much higher radiation doses.