NASA Twins Study on the study of the effect of space on the human body on the example of twins confirmed that after a year spent on the ISS, astronaut Scott Kelly’s DNA changed, and 7% of his genes never returned to normal.
Scott was on the ISS from March 2015 to March 2016, while his twin brother Mark Kelly remained on Earth. This was the last mission for Scott, who spent 520 days in space for his career.
At present, astronauts spend only six months on the ISS. However, the mission to Mars can take three years. According to representatives of NASA, this annual experiment is a step forward for the implementation of a long-term Martian mission.
The researchers followed the psychological and physiological state of Scott and compared it to his brother’s condition. In particular, they examined various proteins and assessed the cognitive abilities of twins. Ten research groups presented their preliminary results last year under the NASA Human Research Program 2017 Investigators Workshop (IWS). And recently these results have been confirmed.
According to scientists, space travel is associated with stress due to lack of oxygen, increased inflammatory processes and striking shifts in the nutrient system, which caused certain genetic changes in the astronaut’s body.
In 2017, researchers found that the end sections of Scott Kelly’s chromosomes – his telomeres – became longer while he was in space. Further testing confirmed this and showed that the majority of telomeres fell again two days after his return to Earth.
It was found that 93% of the Scott Kelly genes returned to normal. However, the remaining 7% may indicate long-term changes in genes related to the immune system, the restoration of DNA, the nature of the formation of bone tissue, the lack of oxygen and elevated levels of carbon dioxide.