( CNN ) NASA is sending astronaut Scott Kelly to live on the International Space Station for a year . That 's the longest any U.S. astronaut has spent in space and twice as long as crew members usually stay on the space station . A year is a long time to stay anyplace . But staying a year in space has some special challenges . There 's what to pack : How many changes of clothes do you bring ? Kelly says NASA supplies most of what he needs but he 's taking his own tool pouch , some sweatshirts and special shoes to use when he 's lifting weights . `` I bought a special kind of shoes I thought would be better for that , '' Kelly said at a NASA briefing on Thursday . Then there 's what to do for a year in space . You get a great view of Earth , so the scenery is amazing . But the space station orbits Earth about every 90 minutes , or about 16 times a day . Could get a little repetitive . So how do you keep from getting bored ? Experiments . Lots and lots of experiments . NASA says space station crews normally work on about 200 experiments over six months , but Kelly will be doing many more . He says he 's actually fascinated with the space station itself as a giant experiment in living in space . `` Building this facility that allows us to understand how to operate for long periods of time in space to allow us someday to go to Mars . '' In his free time Kelly says he 'll spend a lot of time talking to people on Earth , messaging on social media , reading email , watching TV and writing . `` I 'm going to keep a personal journal of the experience , '' Kelly said . He also will share some of his journal with researchers studying the psychological impacts of long-term space flight . Will he tell all ? `` I plan to be completely honest about it , '' he said , but ... `` who knows , maybe there are some crazy thoughts I 'll have at the end that I would n't want to share . '' Kelly also might get to do a bit of singing . British singer Sarah Brightman will visit the station as a space tourist during Kelly 's year in orbit . Will he and the other crew members sing along with her ? `` It will be either all of us or none of us , '' Kelly joked . One other thing Kelly has to plan for : near-zero gravity . Turns out our bodies really like gravity . Stay in orbit too long and your eyes , heart , bones , muscles -- basically everything -- change , and usually not for the better . On the upside , you get a bit taller . At least briefly . `` You do grow when you 're up there for a long time , '' Kelly said . `` Unfortunately it does n't last . But it did last long enough that I could stand next to my brother and look down at him a little bit . '' Kelly was joking about his twin , former astronaut Mark Kelly ( who is also known for being the husband of former Rep. Gabrielle Giffords ) . Mark Kelly has volunteered for NASA 's `` Twins Study '' -- 10 investigations into how the identical twins change over the year in two very different environments . Even though Mark will be on Earth getting poked and prodded by researchers while Scott makes history in orbit , Scott said his brother does n't mind . `` He thinks it 's great that he can still be a participant in this , '' Scott Kelly said . The Kelly brothers ' experiments should help NASA understand what happens to astronauts who spend a long time in space and help plan longer spaceflights to an asteroid or to Mars . Despite all the health risks and personal sacrifices , Kelly said there 's a big reason to stay in space a year . `` It 's a lot of fun , '' he said . `` Space station is a magical place . '' The mission is a first for NASA , but not for Russia . Between 1987 and 1995 , four cosmonauts spent a year or more in space . And another Russian will be with Kelly for his yearlong mission : cosmonaut Mikhail Kornienko . Both men are space veterans . Kelly has flown on two shuttle missions and has already done two stints on the space station . In all , he 's logged more than 180 days in space . Kornienko has spent 176 days in space . The two will ride to the space station on a Russian Soyuz spacecraft along with Russian cosmonaut Gennady Padalka , who is staying for six months . The trio will launch from the Baikonur Cosmodrome in Kazakhstan on March 27 .
Astronaut Scott Kelly to live in space one year . Comment: