• The International Space Station (ISS) is a habitable artificial satellite.
• ISS is the largest man-made object in space launched on November 20, 1998.
  • Its first component was launched into orbit in 1998 and new modules were added as recently as 2021.
  • The Space Station was taken into space piece-by-piece and gradually built in orbit, approximately 400 km above the Earth’s surface.
• The ISS is the largest human made object ever to orbit Earth.
• Orbit:ISS orbits at an altitude of between 370–460 km (Low Earth Orbit).
• It falls towards Earth continually due to atmospheric friction and requires periodic rocket firings to boost the orbit. 
• Speed:The International Space Station completes a full orbit around the Earth at a speed approximately 28,000 km/h, which is 17,500 miles per hour, every 90 minutes. This means astronauts see a sunrise or sunset every 45 minutes. Astronauts aboard the ISS experience 16 day-night cycles in a single Earth day.
• The station is divided into two main sections: the Russian Orbital Segment (ROS), developed by Roscosmos, and the US Orbital Segment (USOS), built by NASA, ESA, JAXA, and CSA. 
• Participating States: ISS is a collaborative project of the United States (NASA), Russia’s (Roscosmos), Europe’s (ESA), Japan’s (JAXA), and Canada’s (CSA) space agencies.
• NASA intends to keep operating the ISS until the end of 2030, after which the ISS would crash into Point Nemo over the South Pacific Oceanic Uninhabited Area (SPOUA).

Purpose:

• The ISS was originally intended to be a laboratory, observatory, and factory while providing transportation, maintenance, and a low Earth orbit staging base for possible future missions to the Moon, Mars, and asteroids.
•  However, not all of the uses envisioned in the initial memorandum of understanding between NASA and Roscosmos have been realised.
• In the 2010 United States National Space Policy, the ISS was given additional roles of serving commercial, diplomatic,and educational purposes.