What Is The International Space Station?
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The International Space Station (ISS) is a research laboratory in low Earth orbit, about 250 miles above Earth. It has been continuously occupied by rotating crews since November 2000. The ISS is operated by a partnership of NASA, Russia's Roscosmos, ESA, Japan's JAXA, and Canada's CSA, and represents the largest international cooperation in space.
The International Space Station is humanity's most ambitious construction project in space. It's a research laboratory orbiting Earth at about 250 miles up, continuously occupied by astronauts since November 2000. The ISS is a partnership of multiple national space agencies, with components from countries around the world. It celebrated 25 years of continuous human presence in November 2025.
How big is the ISS?
Larger than a six-bedroom house. According to NASA, the ISS is about 357 feet long, larger than a football field. It has six sleeping quarters, two bathrooms, a gym, and a 360-degree view cupola for Earth observation. The pressurized interior volume is comparable to a six-bedroom house, providing room for crews of up to seven. The ISS weighs about 925,000 pounds and orbits at 250 miles altitude at 17,500 mph, completing one orbit every 90 minutes. The station can be seen from Earth with the naked eye on many nights.
Who built and runs the ISS?
A partnership of five space agencies. NASA, Russia's Roscosmos, the European Space Agency (ESA), Japan's JAXA, and the Canadian Space Agency (CSA) jointly built and operate the ISS. Components from over a dozen countries make up the station. Construction began in 1998 with the launch of the Russian Zarya module. The first long-duration crew arrived in November 2000, and the station has been continuously occupied ever since. Spacecraft from multiple countries deliver crew and cargo to the ISS, including SpaceX's Crew Dragon and Russian Soyuz spacecraft.
What do astronauts do on the ISS?
Research, mostly. The ISS is primarily a scientific laboratory, with experiments in microgravity physics, biology, materials science, medicine, and Earth observation. Thousands of experiments have been conducted aboard the station, contributing to medical advances, materials science breakthroughs, and climate research. Astronauts also perform maintenance, exercise to manage health effects of microgravity, and occasionally conduct spacewalks for external repairs. The ISS has hosted over 278 spacewalks since 1998. International cooperation is a key aspect of daily life aboard the station.
How long will the ISS keep operating?
Through at least 2030. NASA and partners have committed to operating the ISS through 2030, after which it's expected to be deorbited. SpaceX has been contracted to build a deorbit vehicle for a controlled re-entry. Commercial space stations are being developed to replace the ISS's role. Several private companies are building successor stations expected to begin operations in the late 2020s or early 2030s. The ISS itself has exceeded most original expectations for service life.
The International Space Station is a research laboratory in low Earth orbit, continuously occupied since November 2000. It's the largest international space cooperation project ever undertaken and one of the most ambitious construction projects in human history. The ISS celebrated 25 years of continuous human presence in November 2025 and will continue operating through at least 2030. After that, commercial successors are expected to take over the role of human presence in low Earth orbit.
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