Space Travel Isn't As Glamorous As You Think
Space travel is well known for being an extremely dangerous line of work. You only need to watch 'Gravity' to see how astronauts constantly face extreme stress and high risk of immediate danger and death. Beyond immediate catastrophe, NASA is now focusing on the negative health effects of long duration space flights on human health with a year-long studyaboard the International Space Station. Even though astronauts are required to be in prime physical and mental shape before being cleared for takeoff, they are often left weakened, sick, and even depressed upon their return to Earth.
A space launch entails great acceleration as G-forces build, this can cause astronauts to lose consciousness as their blood supply travels downward from their brain. Current spacecrafts like the Russian Soyuz have dealt with this by orienting astronauts so that they experience most pressure in their chests. However, astronauts still sometimes "grey out" due to losing blood pressure in their head.
About 10 minutes after launch, some astronauts begin to suffer from what's known as "space sickness" due to the lack of gravity pressure on the inner ear. They often complain of a loss of balance and coordination, nausea, and vomiting.
After a week in space, the lack of gravity begins to start muscle and bone deterioration. The weakness caused by this may not become fully apparent while in space, but when astronauts arrive back on earth, they may experience such significant bone loss (sometimes up to 1-2% on load bearing parts of the body) that it's a struggle to even walk once they're back on Earth's terrain.
And that's just the physical dangers. Psychologically, space travelers are likely to suffer consequences from the isolation and deprivation they often experience on long-term space missions. Space agencies have attempted to alleviate these mental health risks by providing their astronauts with behavioral health training and improving communication technology so that they can communicate with people on Earth more effectively.
Sleep disorders, immune system damage, and cosmic radiation exposure are just a few of the other detrimental impacts of spending a prolonged amount of time in space.
Kevin Fong, founder of the Center for Altitude, Space, and Extreme Environment Medicine at University College London describes how space travel pushes a person's body to its limits and takes its toll on health by writing "Space isn't an environment we've evolved to survive in. It's wrong to conceive space travel as this long haul flight with some floating around thrown in - it's an expedition, like any other expedition.
With NASA hoping to send humans to Mars, conquering such space-borne ailments has become more than a curiosity, it's a full-blown necessity.