Zero gravity and its effects on the human body have been studied for many years, and the subject is receiving a great deal of attention nowadays.
The Human Research Program aims to push forward with research into how our bodies are affected by space, in order to make sure that humans can withstand longer deep space missions. For example if plans for a manned mission to Mars come to fruition, humans could be in space for longer than ever before, according to CNN.
Humans struggle to adapt to zero gravity
In order to investigate how this could affect astronauts, NASA has been studying crew members on the International Space Station (ISS). Normally the astronauts live on board for 6 months, but recently Scott Kelly spent a record breaking year on board the space station.
Humans have a strange time readjusting to gravity, as astronauts Mike Hopkins relates. “I felt like I was falling,” he said. “It was as if you’re hanging off the rafters in a building and you let go, and that lasted for about 24 hours. My brain was taking a little while to get used to the fact that there was no up and down anymore. And that went away fairly quick. It takes a little while to get used to floating, too. It’s almost like learning to walk all over again, a little bit.”
The readjustment of fluids in the body leads to a number of symptoms such as a stuffy nose, disorientation and a dulling of the sense of taste. Many astronauts also experience space motion sickness which can cause dizziness and vomiting.
Health effects can be serious
There are also long-term effects such as the weakening of bones and muscle atrophy. Astronauts can suffer a reduction in blood volume, weakened immune systems and a weakening of the cardiovascular system.
To combat these effects there are exercise machines on the ISS and a program of supplements. The exercise not only maintains physical health, but helps to provide a mental release.
One interesting effect involves eyesight, and scientists claim that visual activity is slightly altered. “It changes their visual acuity,” Charles said. “They’re not able to see things up close. It’s like advanced aging. That sort of thing happens at a sort of an accelerated rate.”
Future research needed for safe deep space missions
Another concern is radiation. While astronauts are protected by the ISS, a Mars mission would carry increased risks. By exposing astronauts to galactic cosmic rays, NASA risks causing radiation sickness, reduced cognitive and motor function, and increased risk of cardiac and circulatory diseases.
Issues can continue after landing back on Earth. “[It] took a little bit longer to get used to life in gravity again,” Hopkins said. “I had some issues with, like, pitching moments. It just felt like if I bent [over], I would fall right on my face. And in microgravity, you lose references to how much things weigh. And so I remember when I first landed and I was laying in the Soyuz [the capsule used for landing] and I was just handing out our flight procedures. And that little book that maybe weighs a pound and a half felt like it weighed 25 or 30 pounds.”
Although our bodies were not designed for space living, the Human Research Program is trying to find ways that we can at least survive. Thanks to ongoing study and new proposals, astronauts should be well prepared when they embark on deep space missions planned in the 2030s.
“Mother Nature always tells you the right answer, but you just have to ask the right question,” Charles said. “Our human bodies are up to the challenge of a trip to Mars and back.”