US astronaut Scott Kelly and Russian cosmonaut Mikhail Kornienko will start a one-year research mission in space in March 2015, NASA said in a statement on Thursday.

      Scott Kelly is expected to become the first American astronaut to spend a year in space. Russian cosmonauts have more experience in carrying out long space missions, as four of them have already had missions of one year and even more.

      "In March 2015, American Astronaut Scott Kelly and Russian Cosmonaut Mikhail Kornienko will begin collaborative investigations on the International Space Station (ISS). They will reside on the ISS for a year, which is twice as long as typical U.S. missions," the NASA's statement read.

      During and after the experiment, the American scientists will be studying the absense of gravity and its influence on the astronauts' health. They also will be involved in the scientific experiments "on the medical, psychological and biomedical challenges faced by astronauts during long-duration space flight."

      According to US media, Kelly's twin brother Mark, who is also an astronaut, will participate in the experiment as well, as NASA intends to compare the effects of weightlessness on people with similar genetics.