( CNN ) -- The crew of the International Space Station marked the 10th anniversary of continuous human occupation of the orbiting science laboratory with a typical workday , pausing only briefly for a chat with NASA chief Charles Bolden and questions from international reporters . `` It 's kind of mind-boggling when you stop and think about what you 've done , '' Bolden told the crew . Bolden is a former NASA astronaut who flew on four space shuttle missions prior to the station 's 2000 opening . The football-field sized platform passed the 10-year mark early Tuesday , some 57,361 orbits of Earth after the first crew came aboard , according to NASA . On October 25 , the station eclipsed the previous record for constant human living in space , passing the Russian space station Mir . Since the first module , the Russian-built Zarya , launched on November 20 , 1998 , 103 vehicles have traveled to the station , bringing 196 people to visit or live long-term and conduct science experiments and other work , according to NASA . The station has traveled more than 1.5 billion miles -- the equivalent of eight round trips to the Sun . Human habitation of the station began in 2000 . Bolden said the international flavor of the station 's construction , supply system and staffing do more to prove that humans can get along than many earthbound diplomats , Bolden told the astronauts . `` You 're part of an amazing legacy there on the station , '' he said . People need look no further than the anniversary to recognize the station 's most remarkable accomplishment , said astronaut Shannon Walker . `` Ten years of constant habitation in space is an amazing achievement in and of itself , '' she said . But the station has also produced advances in science , medicine and environmental technology that are helping change life on Earth , according to NASA . The agency says more than 600 science experiments have been conducted aboard the station , with results helping produce new strategies to deliver cancer drugs , advances in vaccine development and a possible treatment for a form of muscular dystrophy , among other things . The commemoration of the anniversary was clouded by the station 's uncertain future . While the 15 nations involved in the space station program have agreed in principal to continue operating it for another decade , the United States is scheduled to retire its space shuttle fleet after two more flights -- cutting off a main supply route to get materials to the station . While Russian spacecraft and commercial providers are expected to take up some of the slack and help keep the station operating for another 10 years , station crew members acknowledged that the shuttle 's retirement will make the station 's mission more challenging . `` I think it 's not a real problem to supply the station with consumables and some other items , but I think it 's a real problem to deliver the results , '' Russian cosmonaut Alexander Kaleri said during a news conference with reporters . `` Now we can deliver only digital data , but sometimes it 's necessary to bring back some physical items . ''
Monday was the 10th anniversary of a constant human presence aboard the station . It 's now the longest continuously lived-in space vehicle in history . Comment: