One of Wikipedia’s latest featured photos: the International Space Station (ISS), taken in 2011 by Italian astronaut Paolo Nespoli from a departing Russian Soyuz spacecraft, while the ISS was docked Space Shuttle Endeavor. It is the largest human-made body in low Earth orbit and can often be seen with the naked eye from Earth, making close to sixteen rotations around Earth daily.
First sent into low Earth orbit in 1998, the space station has been continuously inhabited since 2000; though the last component was fitted in 2011, the station continues to be expanded and developed, with more additions planned for next year. The ISS operated jointly by the American, Russian, Japanese, European, and Canadian space agencies, and has been visited by personnel from seventeen nations. Its ownership and use is governed by various treaties and agreements.
The station is divided primarily between the Russian Orbital Segment (ROS) and the U.S. Orbital Segment (USOS). It also consists of pressurized modules, external trusses, solar arrays, and a microgravity and space environment research lab where crew members conduct experiments in biology, physics, astronomy, meteorology, and many other fields. It is also suited for testing spacecraft and equipment required for lunar and Martian missions.
The ISS has been serviced by a variety of spacecraft, including the Russian Soyuz and Progress, the American Dragon and Cygnus, the Japanese H-II Transfer Vehicle, and formerly the American Space Shuttle and the European Automated Transfer Vehicle. Since 2011, the Soyuz has been the sole means to transfer personnel, while the Dragon is the only provider of bulk cargo return to Earth.
The ISS is the ninth space station to be inhabited by crews, and only the second not to be Russian, following the Soviet / Russian Salyut, Almaz, and Mir stations and the American Skylab. It also surpassed the record for longest continuous human presence in low Earth orbit, having surpassed Mir’s record of nine years and 357 days.
The station is expected to operate until at least 2028, with the American portion being funded until 2025 and the Russian portion until 2024. Both Russia and America have discussed developing an ISS replacement, although NASA has yet to confirm for certain if this will happen; for their part, the Russians have proposed using elements of their section for a new Russian space station, OPSEK.
The ISS is an enduring, if limited, demonstration of the fruits of global cooperation in space exploration. Various other rising space powers, including Brazil, China, and India have also discussed joining the project, or devising their own space stations.