Astronaut Scott Kelly has touched down safely on Earth after his historic 340-day, year-in-space mission aboard the International Space Station. He, along with Russian cosmonaut Mikhail Kornienko, arrived in Kazakhstan at 11:26 p.m. EST.
Joining his return trip aboard a Soyuz TMA-18M spacecraft was Sergey Volkov of the Russian space agency Roscosmos. He arrived on the station on Sept. 4, 2015.
"Scott Kelly's one-year mission aboard the International Space Station has helped to advance deep space exploration and America's Journey to Mars," NASA Administrator Charles Bolden said. "Scott has become the first American astronaut to spend a year in space, and in so doing, helped us take one giant leap toward putting boots on Mars."
During the one-year mission, the ISS crew conducted almost 400 investigations in order to advance NASA's mission. Kelly and Kornienko specifically participated in a number of studies to help with NASA's Journey to Mars mission, including research on how the human body adjusts to weightlessness, isolation, radiation and stress during long-term spaceflight.
The crew also took advantage of the unique vantage point of the space station in order to monitor and capture images of Earth. They also welcomed the arrival of a new instrument that will help them study the signature of dark matter. They also conducted technology demonstrations that continue to drive innovation, such as a test of network capabilities for operating swarms of spacecraft.
Now it's the end of Kelly's mission. So far, he's spent a total of 520 non-consecutive days in space. That's the most among U.S. astronauts. Kornienko has accumulated 516 days in space, and the record holder, Volkov, has a total of 548 days in space on three flights.
Currently, Expedition 47 is still operating the station with NASA astronaut Tim Kopra in command. And while Kelly is now on the ground, he is still helping researchers with experiments. He will be monitored so that NASA scientists can see the full extent of the effects of space on the human body.
The next people to soar to the International Space Station will be NASA astronaut Jeff Williams and Russian cosmonauts Alexey Ovchinin and Oleg Skripochka, which are scheduled to launch from Kazakhstan on March 18.
