On February 29, 2016, American astronaut, Scott Kelly turned over the command of the International Space Station to his fellow NASA astronaut Timothy L Kopra and climbed into a Russian Soyuz capsule the next day. A few hours later, he landed in Kazakhstan, ending 340 consecutive days in space — a record for a NASA astronaut. The previous record was 215 days, reached by Michael Lopez-Alegria during a trip to the space station in 2006 and 2007. Counting his three previous trips to space, Scott has spent a total of 520 days in orbit.
The International Space Station (ISS) zips around Earth at more than 17,000 miles per hour, or once every 90 minutes. That means over the course of Scott’s stay, the space station will have made 5,440 orbits, and the sun will have gone up and down 10,944 times from the perspective of the astronauts aboard. Of course, Scott did not see all of them. He was not continuously looking out the window, and he had to sleep, too.
“We’ll learn a lot about longer-duration spaceflight,” Scott said during a news conference on NASA Television. “I’d like to think this is another of many stepping stones to landing on Mars sometime in our future.” Some of the memorable sights from space included auroras and Hurricane Patricia in October, Scott said.
“The more I look at Earth, at certain parts of Earth, the more I feel more of an environmentalist,” Scott said, “There are definitely areas where the Earth is covered with pollution almost all the time, and it’s not good for any of us.” In the absence of gravity, bones become more brittle, fluids in the body move upward, and vision sometimes shifts towards farsightedness. Scientists are also interested in how quickly the astronauts re-adjust to gravity. After landing, Scott had a series of tests on his balance, including navigating an obstacle course. Scott said he was particularly intrigued by research on genetic changes that occur in space, which scientists will try to glean from comparisons with his twin brother, Mark E Kelly, a retired NASA astronaut.
But with just two test subjects who spent 340 days in orbit, there will not be definitive answers. “We simply don’t have that many people flying in space,” Charles W Lloyd, a NASA manager for communications about the agency’s human research program, said in an interview. “But we still need to understand how space potentially affects you.”