CAPE CANAVERAL, Fla. (December 3, 2012)--The two men who will spend an entire year together aboard the International Space Station are already bracing for a challenging mission.

NASA astronaut Scott Kelly said Wednesday it will be like spending a whole year at the office with no chance of leaving.

Kelly and Russian cosmonaut Mikhail Kornienko will lift off in 2015 for the longest mission ever at the space station, as NASA and the Russian Space Agency try to determine how weightlessness affects the men.

Russia already has experience with yearlong space travel, but it was limited to the old Mir space station and more than a decade has passed since the mission.

Kelly says his 9-year-old daughter screamed "awesome" when she learned the news.

Kornienko's wife, on the other hand, cried.

Kelly is the brother-in-law of former congresswoman Gabrielle Giffords.