<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, the last pressurised module was fitted in 2011, and the station is expected to operate until 2028 . Development and assembly of the station continues, with components scheduled for launch in 2018 and 2019 . The ISS is 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 programme is a joint project among five participating space agencies: NASA, Roscosmos, JAXA, ESA, and CSA . The ownership and use of the space station is established by intergovernmental treaties and agreements . The station is divided into two sections, the Russian Orbital Segment (ROS) and the United States Orbital Segment (USOS), which is shared by many nations . As of January 2018, the American portion of ISS is being funded until 2025 . Roscosmos has endorsed the continued operation of ISS through 2024 but has proposed using elements of the Russian Orbital Segment to construct a new Russian space station called OPSEK . </P>

How far out is the international space station