Get Some Rest
It takes one and a half hours to orbit the planet, so astronauts are treated to sixteen spectacular sunrises and sunrises per day. The novelty of these natural light shows eventually wears off once the fatigue sets in, however. As their sense of night and day is altered, being able to get a “full night’s” sleep is almost impossible. Closet-like cabins and designated “shuttered” hours help the issue, but the lights never truly go out. Anyone dozing off in their space cocoon will notice flashes of brightly colored lights caused by the radiation in cosmic rays slashing through their brain. While these retinal flashes are painless, they are annoying and the radiation can lead to more serious problems such as decreased immunity and a higher risk of cataracts, cancer, heart disease, damage to the central nervous system and brain damage.
Space Makes You Clumsy
In order to maintain balance on earth, your inner ear and muscular sensors seek terrestrial and gravitational clues. In space your body and senses have to rely on visual clues for balance, but even that can be confusing as there is no up or down in space. The result? Imagine a bull in a china shop. After a few days, however, the body acclimates and astronauts are able to move through the space craft with grace and ease without leaving a trail of destruction in their wake.
What Happens When You’re Back On Solid Ground?
International Space Station (ISS) crew member Russian cosmonaut Fyodor Yurchikhin holds the torch of the 2014 Sochi Winter Olympic Games after landing in a remote area near the town of Zhezkazgan in central Kazakhstan on November 11, 2013. Three astronauts returned to Earth on November 11, after 66 days aboard the International Space Station, bringing back the Olympic torch back to the planet after a historic space walk. Credit: Shamil Zhumatov/AFP/Getty Images
So now that you’ve made it safely back to earth, you’ve got to get used to that crazy thing we call gravity again. Astronauts risk low blood pressure upon reentry as the blood rushes to lower extremities resulting in lightheadedness, but long-term effects are also a scary possibility. Depending on how long an astronaut has been in zero-gravity conditions, the tiny muscles that send blood upwards may have atrophied so much that they are not able to pump blood back to the heart causing fainting spells and dizziness. Astronauts drink salt water to increase the volume of fluids in their body to help their bodies adjust to reentry.