The 2017 A Year in Space documentary follows American astronaut Scott Kelly on his year-long mission onboard the International Space Station (ISS).
One of the main objectives of Kelly's mission was to compare how living in space for such a long time affected his body in comparison to his identical twin brother Mark Kelly (who is also an astronaut).
This groundbreaking research is just one of the many steps needed to bring in a new era of human deep space travel.
