Space is a dangerous unfriendly place. An endless environment where you’re isolated from family and friends, exposed to radiation that could increase your lifetime risk for cancer. A diet that consists of tasteless dried food and mandatory daily exercises are necessary to keep your muscle and bones from deterioration. Astronauts go through all this to do their job. The human body is vulnerable to any change in the environment. But what exactly happens to your body in space and what are the risks? Are the risks the same for six month on the space station versus three years on a mars mission? The answer is no. There are several risks and this risks are grouped into five categories: gravity field, isolation, closed environment, space radiation and distance from the earth. But what is the effect of space flight on the human body?
Space presents unique stresses to the human body. Long term exposure causes health problems. One of the significant being loss of bone and muscle mass over time. These deconditioning effects can impair an astronaut’s performance. It can increase their risk of injury and reduce their aerobic capacity. In addition, it can slowdown their cardiovascular system. Space flight also affects astronauts’ eyes causing what’s now called space flight-association neuro-ocular syndrome characterized by swelling in the optic nerve head among other symptoms. Additional symptoms include fluid redistribution, loss of body mass, nasal congestion, sleep disturbance and excess flatulence. Astronauts in space flight are exposed to higher levels of radiation without the earth’s atmosphere there to act as a filter. Radiation levels are about eight times higher on mars than there are on earth.
Effect of Space Flight on the Kelly Brothers
To find out how space affects the human body, twin brothers Mark and Scott Kelly participated in NASA’s twin study. After a year long mission at the station which was twice as long as usual. Scientists compared Scott’s physical parameter with those of Mark’s who had remained on earth and returned on March 1,2016. Three years later, the result of the study announced from NASA’s Houston headquarters showed that long term space missions are likely to cause major changes to astronauts’ metabolisms, genetics and cognitive performance. What’s more, the change could last months after an astronaut’s return to earth, if not longer. Since the Kelly brothers are genetically identical, researchers were able to control for genetic difference in the study, so that the only change that would be seen would be because of environmental changes
Scott’s Return to Earth and NASA’s findings
By the end of the mission Scott had shown clear signs of DNA damage(due to the radiation he was exposed to in space),dehydration and cognitive decline, the researchers found. Several months after his return to earth, Scott continued to exhibit these effects of space on his body. However, its unclear how permanent these effects are or if they are even totally related to his time in space. Many of his telomeres stretchers of DNA, that protect our genetic data and have been associated with a persons lifespan, were also shorter.
NASA is taking action on all of these risks and trying to minimize or mitigate the negative effects on the human body. The result of the one year mission will provide more insight into these changes over a longer period of time, and present a stepping stone for even longer missions.
Written by Heran Getaneh