NASA Marks 25 Years of Continuous Human Presence in Space

The International Space Station has been continuously manned by astronauts and cosmonauts since Nov. 2, 2000.

The International Space Station (ISS) during its fly in an undated handout photo. Roscosmos State Space Corporation via AP

A truly out-of-this-world celebration broke out among NASA leadership on Nov. 2 despite a media blackout due to the government shutdown as humanity marked a continuous presence in outer space for 25 years, thanks to its enduring outpost in low Earth orbit: the International Space Station (ISS).

“On this day 25 years ago, Expedition 1 became the first crew to call the @Space_Station home, launching a continuous human presence in orbit,” Acting NASA Administrator Sean Duffy wrote on X on Nov. 2. “This would not have been possible without @NASA and its partners, as well as every astronaut and engineer who keeps the lights on in low Earth orbit.”

After beginning its orbital assembly in November 1998, the station welcomed its first liveaboard crew, Expedition 1, on Nov. 2, 2000. Since then, it has been a multi-month home to 73 expeditions, as well as played host to short-duration space shuttle missions, commercial flights, and crewed test flights.

Launching from either the Kennedy Space Center in Florida or the Baikonur Cosmodrome in Star City, Kazakhstan, nearly 300 astronauts and cosmonauts from more than 25 countries have visited the station aboard four different manned spacecraft, all but two flying on the Russian Soyuz, NASA’s Space Shuttle, or the SpaceX Crew Dragon. One crewed test flight of the Boeing Starliner made the journey, marking the first time three different crew-carrying spacecraft were docked at once, but technical malfunctions have prevented its return.

Over the years, the station’s expedition crew size has grown from three to seven, but it can host more for shorter handover periods between arriving and departing astronauts.

Those onboard to celebrate the 25-year milestone are NASA Astronauts Jonny Kim, Zena Cardman, and Mike Fincke, Russian Cosmonauts Alexey Zubritsky, Sergey Ryzhikov, and Oleg Platonov, and Astronaut Kimiya Yui of the Japan Aerospace Exploration Agency (JAXA). Cardman, Fincke, Platanov, and Yui arrived onboard a SpaceX Crew Dragon as the 11th crew of NASA’s commercial crew program. Kim, Zubritsky, and Ryzhikov flew a Russian Soyuz.

Construction of the ISS required 37 space shuttle missions and five Russian Proton/Soyuz rockets over more than 10 years, and is made up of components from 15 different countries representing five different space agencies.

It was completed during the final Space Shuttle mission, STS-135, in July 2011. Stretching 365 feet long, weighing 925,335 pounds, and boasting 13,696 cubic feet of habitat volume, it is the largest human-made object ever to orbit the Earth. More than 4,000 groundbreaking scientific experiments have been performed onboard.

Northrop Grumman’s Cygnus, SpaceX’s Cargo Dragon, JAXA’s HTV, and the Russian Progress modules continue to fly unmanned missions delivering supplies, scientific research equipment, and other cargo.

Over the years, private individuals have paid millions of dollars for the opportunity to spend a short stint aboard the ISS as a “Spaceflight Participant,” including a Russian film crew in 2021.

The private space company Axiom Space has also sent four missions of private astronauts, which were commanded by former NASA Astronauts Peggy Whitson and Michael Lopez-Alegria. Axiom-4 visited the Expedition 73 crew from June 26 through July 14.

Whitson has logged more than 18 months of total time aboard the station, setting a U.S. record of most time working and living in space at 665 days on Sept. 2, 2017.

“Congratulations to @NASA and their International Partners on 25 years of continuously crewed operations aboard the @Space_Station,” Axiom Space wrote on X. “Your dedication and collaboration have truly expanded the boundaries of human exploration. As we honor this remarkable achievement in low-Earth orbit, many may be wondering .... what comes next?”

However, the ISS’s tenure is coming to an end. NASA plans to have it burn up in the atmosphere during a controlled deorbit over the Pacific Ocean by 2030.

It also no longer has the skies to itself. China completed its own space station, the Tiangong, in 2022. Its latest crew of Chinese astronauts, known as Taikonauts, launched on Oct. 31 from the Jiuquan launch center in northwestern China and successfully docked several hours later.

Multiple private spacefaring companies are working to develop their own modules to ensure that America continues to maintain not only its presence in low Earth orbit, but also its dominance, while NASA focuses most of its government-backed resources on establishing a human presence on or around the moon.

Vast Space, for instance, has continued to show the progress of its Haven-1 module on social media, with its CEO, Max Hoat, expressing his dedication to ensuring that the United States does not cede its foothold in low-earth orbit (LEO) to any other nation.

“Let me be clear: @vast Haven-1 is the first step toward a multi-module station,” he said on X. “Vast is ready to ensure the U.S. never has a gap in LEO. An American heartbeat has been in orbit every day for 25 years and must remain through and after the ISS.”

Axiom Space is also in the process of building its own station in low Earth orbit.

The Associated Press contributed to this report.