What does the abbreviation ISS stand for?

The abbreviation ISS stands for the International Space Station.

The ISS is a modular research station in low Earth orbit, operated through cooperation among NASA, Roscosmos, ESA, JAXA, and the Canadian Space Agency. Its first module, Zarya, launched in November 1998, beginning an assembly program that used Russian rockets, Space Shuttles, and international crews.

The station is more than a laboratory: astronauts use it to study biology, physics, materials, medicine, Earth observation, and the effects of long-duration spaceflight. Continuous human occupation began when Expedition 1 arrived in November 2000. The station circles Earth roughly every 90 minutes, allowing crews to see many sunrises and sunsets during a single day.

A common mix-up is confusing ISS with a generic phrase such as “international space system.” The official name is “International Space Station,” and ISS is its standard English abbreviation. The term can have unrelated meanings in other fields, but spaceflight questions use it for this orbital outpost.