NASA astronaut Scott Kelly is closing the door on a space mission that has spanned a U.S.-record 340 days.
Kelly and his roommate for nearly a year, Russian cosmonaut Mikhail Kornienko, check out of the International Space Station on Tuesday night, U.S. time. By the time their Russian capsule lands in Kazakhstan on Wednesday, the pair will have circled the world 5,440 times and experienced 10,880 orbital sunrises and sunsets. Their mileage: 144 million miles. Says Kelly, "We did it!"
Kelly's closest U.S. contender trails him by 125 days. Russia continues to rule, however, when it comes to long-duration spaceflight. The world record of 438 days was set by a Russian doctor during the 1990s.
Scientists are hoping for more one-year subjects as NASA looks ahead to Mars trips.