5 questions about the human body the yearlong space mission may answer

  • NASA astronaut Scott Kelly is seen inside a Soyuz simulator at the Gagarin Cosmonaut Training Center, March 4, 2015 in Star City, Russia. NASA/Bill Ingalls

    NASA has a lot of questions about what happens to people who live in space for long periods of time, and it's almost time to get some answers.

    When NASA astronaut Scott Kelly and Russia's Mikhail Kornienko fly up to the International Space Station Friday (March 27) for a yearlong stay on the orbiting outpost, space agency scientists will get to work on experiments that could help get people to Mars one day.

    Officials have a lot of information about what happens to a body in weightlessness for six months, but the 12-month space mission will mark the first time researchers can gather data about what happens to people in space for longer periods of time. It takes more than one year to get to Mars using currently understood propulsion methods, so learning more about the ways long spaceflight affects humans is key to one of NASA's main future goals: getting people to the Red Planet. [1-Year Space Station Mission Explained (Infographic)]

    Here are five of the major questions NASA scientists are trying to answer with Kelly and Kornienko's yearlong space mission.

    Click through to see the questions.

    By Miriam Kramer