The NASA “Twins Study” was a first of its kind, a multidimensional analysis of the impact of long-duration space travel on the human body. It involved Astronaut Scott Kelly spending a year on the International Space Station (ISS), whilst his identical twin Mark acted as a control at home on Earth between March 2015 and March 2016.

The final study concluded that there were short term changes to the way genes were expressed in the body, similar to how the body reacts to the stresses involved in mountain climbing or scuba diving, but there were no changes to Scott’s DNA. These changes in gene expression highlight areas of the human body which may be vulnerable during long term space flight and will assist a guide for targeted countermeasures or monitoring during future missions. (https://go.nasa.gov/2XQwYqA, https://bit.ly/2MmajwW)