The International Space Station is one of the few nonstellar things up there that we can see from down here without instruments. It’s a prefab home the size of a football field, 462 tons and more than $100 billion worth of pressurized roomlike modules and gleaming solar arrays, orbiting 250 miles above the surface of the Earth. Its flight path is available online, and you can find out when it will make a nighttime pass over your backyard. Right on schedule, you’ll spot an unblinking white light that’s moving at 17,500 miles an hour. It will cross your field of view, on a line straight enough to have been drawn with a ruler, in only a few seconds. A few minutes more and the men and women inside that light will be over Greece. A few minutes more, Mongolia.

There have been 53 expeditions to the ISS; 53 long-duration crews have called it home since Expedition 1 floated aboard in 2000. They’ve been mostly from America and Russia, the two principal and unlikely partners in one of the most expensive and challenging construction projects ever completed. (The ISS rose out of the ashes of two previous space stations: Russia’s Mir, last occupied in 1999 before it fell out of the sky in 2001, and Ronald Reagan’s proposed Freedom, which never got past the blueprints.) Its first few residents came and went largely without incident, conducting scientific experiments in everything from fluid dynamics to zero-G botany while studying what month after weightless month can do to the human body.

In November 2002, Expedition 6 arrived on the station’s doorstep. They were two Americans, Ken Bowersox and Don Pettit, and a Russian, Nikolai Budarin. They were supposed to complete a four-month tour in orbit. Then the shuttle Columbia dissolved into a finger of smoke somewhere beneath them in February 2003. The remaining shuttles were grounded, and the men of Expedition 6 were asked to extend their stay. They were told that they might come home in a few months. They might come home in a year. Maybe longer.

Bowersox has three children. Living in space is dangerous and dirty—so much can go wrong, and everything floats—but that time away is a different kind of hard for the families left behind. Bowersox’s children would bundle up time and again that winter and head outside to wait for him to appear in the sky. He would rocket over their heads. One of his children, his then 5-year-old son, didn’t quite understand the nature of orbital velocity, and he would sprint down the street, chasing his dad, trying to keep him in sight.

In the end, Expedition 6 came home in a Russian Soyuz capsule, only a couple of months after their original return date. Their dramatic descent didn’t make many headlines, and, except for Scott Kelly’s recent year-long stint in space, none of the subsequent 47 expeditions have garnered much attention either. Few of us give a thought to the International Space Station, even though, when the future measures our collective contribution to humanity, the ISS will prove the single best thing we did. Less than a century after the Model T was state of the art, we manufactured a kind of galleon in space and have sent men and women from 10 countries to live in it, along with a host of short-term visitors, without recess or mutiny or fatality, for nearly 20 years. By the time the ISS makes its fiery return to Earth, possibly in the late 2020s, it will have become a stepping stone to lunar colonies and the first human mission to Mars. It will have taught us so much about our ability to adapt to the most hostile of environments. The most beautiful too.

Tonight there are a half-dozen brave people, including three Americans, wrapped up in sleeping bags strapped to the cluttered walls there, dreaming of their families and gravity and everything else they’re missing. They are heroes, but the chances are slim that you could recall any of their names. Maybe it will make you feel better to remember instead, if only for the time it takes for the station to cross your night sky, that while everything can seem so awful and cynical here at home, we are still capable of distant miracles. Right now the International Space Station is hurtling through space, and so is its crew, which means so are we, living in its constant light.

Chris Jones ­(@EnswellJones) also wrote about weather blogger Eric Berger in “Eye of the Storm.”

This article appears in the January issue. Subscribe now.