This Is the Worst Thing That Could Happen to the International Space Station

But in the worst worst-case scenario, we don’t have any control. Instead, the station will crack through the atmosphere. Sure, many pieces will likely end up in the ocean, but some might hit people, possibly in a town or a city. The station could break apart across thousands of miles and multiple continents. This would be exceedingly hard to anticipate. As NASA puts it, “Calculating the probability of this penetration cascading into loss of deorbit capability has a very large range of variables, making predictions ineffective.”

This almost certainly won’t happen to the ISS. At the same time, it’s a far more extreme version of the only way an American space station has ever come down. In 1979, after years spent vacant in orbit, Skylab, the US’s first space station, started sinking toward the atmosphere, where it threatened to fall and drop molten spacecraft parts on Earth. At that point, NASA officials had to remotely wake up its computers and, with only limited control of the station, direct it over a location that would endanger the fewest humans.

In the months before, space agency officials were in frequent contact with the State Department, which disseminated the latest predicted trajectories to embassies across the world. In these situations, oops doesn’t cut it: When one of the Salyuts, a Soviet space station model, was deorbited a few decades ago, flaming bits were littered across Argentina, scaring people and requiring the deployment of at least a few firefighters, according to local newspaper reports.

The ISS is far bigger than either the Salyuts or Skylab. In an uncontrolled deorbit, pieces of debris “up to car and train size,” say experts on the official ISS space station advisory committee, will rain down from the sky. NASA confirms this would pose “a significant risk to the public worldwide.”

OK—the nightmare is over. Thus concludes my anxiety-ridden spiral. Here are the facts as they stand in 2026:

As far as WIRED can tell, no one has ever died because a piece of space station hit them. Some pieces of Skylab did fall on a remote part of Western Australia, and Jimmy Carter formally apologized, but no one was hurt. The odds of a piece hitting a populated area are low. Most of the world is ocean, and most land is uninhabited. In 2024, a piece of space trash that was ejected from the ISS survived atmospheric burn-up, fell through the sky, and crashed through the roof of a home belonging to a very real, and rightfully perturbed, Florida man. He tweeted about it and then sued NASA, but he wasn’t injured.

For this story, WIRED reviewed dozens of NASA documents, including backup plans and contingencies for emergencies, and spoke to more than a dozen people, including three astronauts who’ve visited the ISS, and no one seemed that freaked out. One astronaut said the most worrisome scenario that actively crossed his mind in orbit was getting a toothache. The ISS has had some emergencies, including a first-ever medical evacuation in January, but generally things have been remarkably stable. In fact, one of the most impressive things about the ISS is that nothing very dramatic has ever happened to it. No experiment has gone too haywire. It hasn’t been hit by an asteroid.