International Space Station Russian space station called OPSEK. 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 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 held by "Mir". It has been visited by astronauts, cosmonauts and space tourists from 17 different nations. After the American Space Shuttle programme ended in 2011, Soyuz rockets became the only
Medium Earth orbit constellations. Communications satellites that cover the North and South Pole are also put in MEO. The orbital periods of MEO satellites range from about 2 to nearly 24 hours. Telstar 1, an experimental satellite launched in 1962, orbited in MEO. The orbit is home to a number of artificial satellites. Medium Earth orbit Medium Earth orbit (MEO), sometimes called intermediate circular orbit (ICO), is the region of space around Earth above low Earth orbit (altitude of above sea level) and below geostationary orbit (altitude of above sea level). The most common use for satellites in this region is for navigation,