Science fiction has long promised an age of interplanetary human existence. Scenes of spaceships hopping from one galaxy to the next are so common, it seems almost inevitable that future generations will one day vacation on Mars. But, if we are ever going to achieve life on other planets, we first have to figure out if the human body can tolerate it.
Some of the best data we have on the subject comes from American astronaut Scott Kelly. Kelly spent a year living on the International Space Station while his twin brother Mark, also an astronaut, was on Earth. Scientists from all over the country studied the impact life in space had on Scott Kelly, and compared changes in his body to his brother.
One of those scientists was UC San Diego Professor of Medicine, Michael G. Ziegler, MD. In a recent talk at UC San Diego Extension’s Osher Lifelong Learning Institute, Ziegler detailed some of the more interesting findings from the study. Scott Kelly lost weight. There were significant changes to his gene expression. He lost collagen. His carotid artery thickened. His bones became less dense. His eye shape changed, forcing him to wear glasses. While he was in space, his performance on cognitive tests improved. But, his performance plummeted after returning to Earth, and never quite returned to pre-launch levels.
Despite all of this, Ziegler has reason to be hopeful about long-term space travel. He says the year in space study illuminated many of the challenges, and gave researchers some ideas of how to overcome them. Still, it’s probably a little early to start planning your trip to the red planet.