Mark & Scott Kelley

For several years now we have been posting about Scott and Mark Kelly, the identical twins who both graduated from merchant marine academies and served in the Navy.  Each became astronauts and both have traveled in space. Recently, Scott Kelly returned from an epic one-year mission aboard the International Space Station, the longest any American astronaut has ever spent in space.

Mark Kelly, now retired,  also playing a key role in the mission. As the only identical twins to serve as astronauts, Mark is now acting a control against which to compare the physiological changes that may have taken place in his twin brother Scott during his year in space.

One change in his brother was immediately noticeable. During his year in zero gravity, Scott Kelly has grown two inches taller than his twin brother Mark. Scott reports that overall he “feels pretty good. ” He will now begin what may be a year-long project to monitor his health.