NASA astronaut Scott Kelly is preparing to push the limits of human habitation of space. Next month, Kelly will begin a yearlong mission aboard the International Space Station, becoming the first American astronaut to spend a year in zero-gravity. "The goal of the mission is to study the effects of long-term space flights on the human body," said UTMB’s Dr. Tarah Castleberry. “A body is made for and adapted to gravity, but when you go into space you’re only at zero or very low gravity,” Castleberry said. The shift to zero-gravity can cause muscle and bone to deteriorate, and affects the body’s metabolic system. Information from Kelly’s mission will be used by NASA as it continues to plan for a manned mission to Mars. Being able to predict how a body will hold up over an extended period in space is an important hurdle to overcome. [Note: Paid subscription required. Contact UTMB Media Relations for details.]