On Halloween in the year 2000, a Russian Soyuz rocket launched from Kazakhstan and flew into the history books, carrying one U.S. astronaut and two Russian cosmonauts to the nascent International Space Station (ISS).
The crew arrived two days later, and the space station has been continuously occupied by humans ever since, a 20 year streak of living and working in low-Earth orbit. “There’s kids now who are in college who, for their entire lives, we’ve been living off the planet,” says Kenny Todd, NASA’s deputy program manager for the ISS. “When I was a kid, that was all stuff that was just dreams.”
The orbiting laboratory is among the most expensive and technologically complex objects ever built: a $150 billion pressurized habitat as long as a football field, whizzing 254 miles above Earth’s surface at 17,000 miles an hour. Over the decades, 241 women and men from around the world have temporarily called the space station home, some for nearly a full year at a time.
Upward of a hundred thousand people have worked together to design, build, launch, and operate the sprawling station, says David Nixon, who worked with NASA on ISS designs in the mid-1980s. “When you compare the station to the procession of great structures and buildings built by humanity since the dawn of civilization, it’s up there with the Pyramids, the Acropolis—all the great structures and edifices,” he says.
Like Earth’s most enduring structures, the ISS was decades in the making. Born out of the U.S.’s concept for “Space Station Freedom” in 1984, the project gradually evolved into a 15-nation pact between the U.S., Canada, Japan, Russia, and the eleven member states of the European Space Agency. The first pieces of the ISS started arriving in orbit in 1998, and Expedition 1 crew members climbed aboard the newborn station on November 2, 2000. The station now hosts Expedition 64.
“You just have this impression that we’re all citizens of not a particular country, but of the planet,” says retired NASA astronaut Scott Kelly, who spent nearly a year on one ISS stay. “We’re all in this thing called humanity together.”