NASA astronaut Scott Kelly paved the way for future missions when he embarked on a one-year mission in space along with Russian cosmonaut Mikhail Kornienko. Kelly will be the first American to complete such a long-duration mission, and one of the first humans in more than 15 years to embrace the challenge. Russian cosmonaut Sergei Avdeyev was the last person to spend a year in microgravity in 1999. The 2015-2016 mission builds upon that past knowledge.
One-year mission crew members Scott Kelly of NASA (left) and Mikhail Kornienko of Roscosmos (right) celebrated their 300th consecutive day in space on Jan. 21, 2016. By spending a total of 340 days aboard the International Space Station, the astronauts help scientists understand what happens to the human body while in microgravity for extreme lengths of time. Kelly is holding a zinnia grown in space as part of the Veggie experiment on the International Space Station.