The two men assigned to a one-year spaceflight say their upcoming mission will allow the world to push deeper into space.

NASA astronaut Scott Kelly and Russian Space Agency cosmonaut Mikhail Kornienko will rocket into orbit from Kazakhstan in March. They will spend a year aboard the International Space Station.

At a news conference Thursday at the United Nations Educational, Scientific and Cultural Organization headquarters in Paris, Kelly and Kornienko said they anticipate many scientific gains from their mission. They say scientists need to know more about the prolonged effects of space on humans, before astronauts embark on Mars expeditions lasting three years, round trip.

Kelly and Kornienko have been training for this mission for two years. It will set a U.S. space endurance record. The world record, already claimed by Russia, is 14 months for a single flight.