<Tr> <Td_colspan="2"> Station elements as of June 2017 (exploded view) </Td> </Tr> <P> The International Space Station (ISS) is a space station, or a habitable artificial satellite, in low Earth orbit . Its first component launched into orbit in 1998, and the ISS is now the largest human - made body in low Earth orbit and can often be seen with the naked eye from Earth . The ISS consists of pressurised modules, external trusses, solar arrays, and other components . ISS components have been launched by Russian Proton and Soyuz rockets, and American Space Shuttles . </P> <P> The ISS serves as a microgravity and space environment research laboratory in which crew members conduct experiments in biology, human biology, physics, astronomy, meteorology, and other fields . The station is suited for the testing of spacecraft systems and equipment required for missions to the Moon and Mars . The ISS maintains an orbit with an altitude of between 330 and 435 km (205 and 270 mi) by means of reboost manoeuvres using the engines of the Zvezda module or visiting spacecraft . It completes 15.54 orbits per day . </P> <P> The ISS is the ninth space station to be inhabited by crews, following the Soviet and later Russian Salyut, Almaz, and Mir stations as well as Skylab from the US . The station has been continuously occupied for 7003622000000000000 ♠ 17 years and 11 days since the arrival of Expedition 1 on 2 November 2000 . This is the longest continuous human presence in low Earth orbit, having surpassed the previous record of 7003364400000000000 ♠ 9 years and 357 days held by Mir . The station is serviced by a variety of visiting spacecraft: the Russian Soyuz and Progress, the American Dragon and Cygnus, the Japanese H - II Transfer Vehicle, and formerly the Space Shuttle and the European Automated Transfer Vehicle . It has been visited by astronauts, cosmonauts and space tourists from 17 different nations . </P>

What is the purpose of the international space station (iss)
find me the text answering this question