NASA astronaut Scott Kelly and Russian cosmonaut Mikhail Kornienko are set for a nearly yearlong mission aboard the International Space Station. The veteran space fliers will blast off in a Soyuz spacecraft on Friday at 3:42 p. m. ET from the Baikonur Cosmodrome in Kazakhstan.

According to experts, they will reach their home for the next year, about 250 miles above Earth. Cosmonaut Gennady Padalka will join them for the ride up and he will visit the orbiting research complex for a standard six-month expedition.

By increasing that mission period for two crew members for the first time on ISS, NASA and its partners expect to know more about the issues astronauts could face on even longer voyages to Mars.

"The one-year increment will expand the bounds of how we live and work in space and will increase our knowledge regarding the effects of microgravity on humans as we prepare for future missions beyond low-Earth orbit", said Bill Gerstenmaier, head of NASA's human spaceflight programs when the mission was announced in 2012.

The space agencies are having talks to assign more astronauts to yearlong missions. Wife of Kornienko cried upon by knowing about his second long spaceflight, this time for the whole year. Afterwards, she supported the decision.

Kornienko said they have opportunity to be the first to spend an entire year on the space station. It is going to be of huge use for future generations for science and for those who could fly further to Mars and to outer space.

According to experts, months in space are known to cause loss of bone and muscle mass, weakened immune systems and impaired vision. But the upcoming mission is going to track those health impacts over more time.