Scott Kelly is an American astronaut who spent 340 days aboard the International Space Station (ISS) before landing back on Earth in March 2016. The stay was designed to further NASA’s goal to send astronauts on long-duration space flights to Mars and beyond.
This study to test the endurance in a microgravity environment is known as the Twin Study. As Scott Kelly spent almost a year in space, his identical twin Mark Kelly remained on Earth. Ever since Scott’s return, the two brothers have undergone a number of medical tests to study the long-term effects of microgravity on a person’s physique. The results have recently been released and they show that the changes have been on a genetic level.
NASA’s Human Research Program was responsible for conducting the study. The study showed indications of inflammation, changes in telomeres and telomerase (parts of chromosome related to ageing), a decrease in bone density and gastrointestinal changes. As NASA reported in their preliminary findings:
“By measuring large numbers of metabolites, cytokines, and proteins, researchers learned that spaceflight is associated with oxygen deprivation stress, increased inflammation, and dramatic nutrient shifts that affect gene expression…After returning to Earth, Scott started the process of readapting to Earth’s gravity. Most of the biological changes he experienced in space quickly returned to nearly his preflight status. Some changes returned to baseline within hours or days of landing, while a few persisted after six months.”
The study also looks at genetic changes by comparing the DNA of the brothers. 93% of genes of the American astronaut Scott Kelly were back to pre-flight status but the remaining 7% points were still missing. These were attributed to “longer-term changes in genes related to his immune system, DNA repair, bone formation networks, hypoxia, and hypercapnia.”
The study, however, states that Scott Kelly did not experience any significant change when it came to cognitive performance. There was a slight decrease in speed and accuracy in cognitive performance testing when compared to his brother and it was more pronounced when he first landed and it has been attributed to readjusting to Earth’s gravity.
NASA’s Twin Study was integral for future missions planned for Mars. A number of other studies are also underway to better prepare astronauts on what to expect on a mission that could very well take a couple of years.
Scott Kelly’s stay in space and the Twin Study will also be the subject of a PBS documentary titled Beyond a Year in Space. You can check out the trailer below: