Twenty-five years of humans living and working in orbit

On November 2, 2000, three people climbed aboard an incomplete space station and switched on the lights. A quarter century later, that fragile framework has become humanity's longest continuous human settlement beyond Earth—a place where American astronauts work alongside Russian cosmonauts, where commercial crews now arrive regularly, and where the science happening 250 miles up is reshaping what we know about survival in space.

The first crew—NASA astronaut William Shepherd and Russian cosmonauts Yuri Gidzenko and Sergei Krikalev—launched from Kazakhstan and docked two days later. Their job was simple in concept, staggering in execution: bring a space station to life. They installed life support systems, activated communications, and coordinated with three visiting shuttle crews to keep building. Four months later, they handed the station to the next crew and returned home. That handoff—the seamless passing of a living, working space—became the template for the next 25 years.

The work that made it possible

Building and maintaining the station required something the early space age rarely saw: people in bulky suits, floating outside the station, performing intricate repairs in an environment designed to kill them. More than 270 spacewalks have happened in 25 years. Some became historic moments—Tamara Jernigan became the first woman to spacewalk at the station in 1999; Christina Koch and Jessica Meir conducted the first all-female spacewalk in 2019. Others were quieter: in January 2025, crew members collected samples to study whether microorganisms could survive in space, knowledge that will shape how we protect Mars from Earth contamination.

The station itself evolved too. When SpaceX's Crew Dragon arrived on May 31, 2020, carrying astronauts Robert Behnken and Douglas Hurley, it marked the first time a commercially built spacecraft brought humans to orbit. That single mission opened a new chapter—regular commercial crew rotations, private astronaut missions, the early signs of an actual economy forming in low Earth orbit.

Then there was Frank Rubio. In September 2023, he returned to Earth after 371 days aboard the station—the longest single spaceflight by an American in history. Scientists watched how his body adapted to more than a year without gravity, how limited exercise equipment could still maintain fitness, how diet and psychology held up. The data he and others like him provide aren't academic curiosities. They're blueprints for sending humans to the Moon and Mars.

What 25 years of cooperation actually built

The station operates through a partnership of five space agencies—NASA, Roscosmos, the European Space Agency, Japan's JAXA, and Canada's CSA. At least 290 people from 26 countries have visited. That's not just a statistic about diversity. It's evidence that the hardest problems—how to live in space, how to conduct research in microgravity, how to keep a habitat functioning when you can't just call a repair person—don't require one nation to solve them alone.

The experiments happening up there are already changing life down here. Materials science research improves spacecraft design. Plant-growing techniques developed in orbit inform agriculture on Earth. Health data from long-duration missions prepares crews for journeys that will take months or years.

What started as a fragile framework of modules has become something more durable: proof that sustained human cooperation in the most hostile environment we've attempted to live in is possible. The next chapter—Moon bases, Mars missions, commercial space stations—is already being written by people who learned to work together 250 miles above our heads.