What The International Space Station Is And Why It Is Being Retired

On 2 November 2000, American astronaut Bill Shepherd and Russian cosmonauts Yuri Gidzenko and Sergei Krikalev docked their Soyuz capsule at the International Space Station and moved in. The station, a laboratory orbiting about 400 km above Earth, has had people aboard ever since. NASA and its partners plan to run it until the end of 2030 and then steer it into the ocean.

Image Credit: Scott Kelly, Expedition 44, NASA

That unbroken run of human presence in orbit, now more than a quarter of a century long, is entering its last years. What replaces the station will decide which countries and companies keep people in space, and on whose terms.

What The Station Is

The International Space Station is the largest structure humans have put in orbit, weighing about 450 tonnes. It was assembled piece by piece, starting with the Russian-built Zarya module, launched on 20 November 1998. Five space agencies run it: NASA, Russia’s Roscosmos, the European Space Agency, the Japan Aerospace Exploration Agency and the Canadian Space Agency.

It travels at about 27,600 km an hour, circling Earth about 15.5 times a day, so its crew sees a sunrise or sunset roughly every 45 minutes. By August 2025, 290 people from 26 countries had visited.

What It Has Done

The station’s main product is knowledge about living and working in space. Crews have spent months at a time in near weightlessness, giving doctors data on how the human body loses bone and muscle, how eyesight and the heart change, and how to counter those effects, all of which matter for any future journey to Mars. Researchers have grown crystals, tested materials and studied how fire and fluids behave without gravity. The station has also kept former Cold War rivals working side by side through decades of political strain on the ground.

Why It Is Being Retired

The station is ageing. Its oldest modules have been in orbit for more than 25 years, and maintaining it costs NASA billions of dollars a year. NASA wants to spend that money on the Moon and Mars and to buy time in orbit from private companies instead of owning a station itself.

How It Will Come Down

A structure this large cannot be left to fall at random. In 2024, NASA chose SpaceX to build the US Deorbit Vehicle, under a contract worth up to $843 million. The vehicle is due to arrive in mid-2029. Over two to two and a half years, atmospheric drag and the station’s own thrusters will lower it. The deorbit vehicle will then guide what survives re-entry into a remote, uninhabited stretch of the Pacific Ocean. Some US lawmakers have argued for boosting the station into a higher orbit instead, preserving it.

What Comes Next

NASA plans to replace the station with commercial ones. Several companies are building them. Vast is targeting early 2027 for its first, Haven-1. Axiom Space plans to attach its first module to the ISS before it flies free. Voyager Technologies and Airbus are developing Starlab, and Blue Origin and Sierra Space are working on Orbital Reef. None has yet launched, and their dates have slipped before.

China already has its own. Tiangong, completed in late 2022, has been permanently crewed since June 2022, usually by three astronauts. It is designed for a 10-year life, with a possible extension to 15.

India’s Path To Its Own Station

In June 2025, Indian Air Force test pilot Shubhanshu Shukla flew to the International Space Station as pilot of Axiom Mission 4. He became the first Indian aboard the station and the first member of India’s astronaut corps to fly in space. He spent about 18 days aboard the station with crewmates from the United States, Poland and Hungary.

ISRO chairman V. Narayanan has said India aims to launch the first module of its own Bharatiya Antariksh Station by 2028.

If no commercial station is crewed and flying when the International Space Station comes down, China’s Tiangong will be the only inhabited station in orbit.

Key facts

• The International Space Station has been continuously crewed since 2 November 2000.
• It orbits about 400 km above Earth at about 27,600 km an hour.
• NASA and its partners plan to operate it until the end of 2030, then deorbit it into the Pacific.
• SpaceX is building the US Deorbit Vehicle under a contract worth up to $843 million.