The International Space Station (ISS ) is a habitable artificial satellite, in low Earth orbit.
The ISS is now the largest artificial body in 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 RussianProton and Soyuz rockets as well as American Space Shuttles.
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.
What is Micro gravity?
Microgravity is the condition in which people or objects appear to be weightless. The effects of microgravity can be seen when astronauts and objects float in space.
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 by means of reboost manoeuvres using the engines of the Zvezda module or visiting spacecraft.
It completes 15.54 orbits per day.
The station has been continuously occupied for 15 years and 6 days since the arrival of Expedition 1 on 2 November 2000.
Expedition 1 crew
This is the longest continuous human presence in space, having surpassed the previous record of 9 years and 357 days held by Mir. The station has been visited by astronauts, cosmonauts and space tourists from 17 different nations.
The ISS programme is a joint project among five participating space agencies: NASA(USA), Roscosmos(Russia), JAXA(Japan), ESA(Europe), and CSA(Canada).
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.
On 28 March 2015, Russian sources announced that Roscosmos and NASA had agreed to collaborate on the development of a replacement for the current ISS.
NASA later issued a guarded statement expressing thanks for Russia’s interest in future cooperation in space exploration, but fell short of confirming the Russian announcement.
The ISS is arguably the most expensive single item ever constructed.
In 2010 the cost was expected to be $150 billion.
It includes NASA’s budget of $58.7 billion Russia’s $12 billion, Europe’s $5 billion, Japan’s $5 billion, Canada’s $2 billion.