Considering the size of this thing—nearly 100 feet tall, more than 15 feet across, weighing 23 tons—the idea of even parts of it hurtling toward us is particularly unnerving, enough that a friend whom I haven’t seen in ages sent me this text message last night: “Are you following this China rocket thing? Are we doomed??”
No one is doomed! Not because of this, at least. While the chances are not zero, the likelihood that debris from the Long March 5B will drop onto a populated area is extremely low. Even without a controlled entry, it is far more likely to smash into the ocean, which our planet thankfully has a lot of. (Honestly, the reentry we should probably be more preoccupied with is the return to social interaction after vaccination.) Stuff falls into the atmosphere every day, burning up as it goes. You’re more likely to get struck by lightning than smacked with a piece of falling space debris.
“The chance of someone being hurt is maybe a percent or so,” Jonathan McDowell, an astronomer at the Harvard-Smithsonian Center for Astrophysics who is well known in the space community for his expert monitoring of artificial space objects, told me. “The chance of you being hurt is 8 billion times smaller than that, so don’t worry about it.”
Careening, out-of-control space debris is one of those problems that we hear about precisely because it’s so rare. It’s also quite solvable, McDowell said—just don’t build your rocket, as China did, to reach orbital velocity and start zooming around. The few times that very large pieces of space junk have come crashing down to Earth over the years—rockets, satellites, even entire space stations—no one was doomed.
In the 1970s, Skylab, the first American space station, came plummeting through the atmosphere. NASA astronauts had used the floating outpost to conduct science experiments and generally get the feeling of life in microgravity. By the end of the decade, the station, now abandoned, started losing altitude. The station wasn’t designed to maneuver itself into a higher orbit, and the space shuttles that NASA thought could help haul it up weren’t ready yet, so down the station went. NASA did have the power to give it a nudge or two, but mostly Skylab was carving its own path.
In 1979, as the public followed the station’s descent with, according to Time magazine, “varying degrees of fear, anger and fascination, but mostly with a detached kind of bemusement,” NASA controllers worried that some debris could hit North America. The Federal Aviation Administration even closed off airspace over Maine to protect planes. Hours before reentry, engineers commanded Skylab to fire some engines and produce a wobble that would adjust its path just a bit, bringing its descent over the ocean. The last-minute adjustment was partly successful; most of Skylab fell into the Indian Ocean, but some debris was scattered along the coast of western Australia. Suddenly, space litter became a souvenir, and people scoured the coast for remnants of Skylab, eager for a trophy or something to sell. The city council of Kalgoorlie even hauled a piece of the station into its town hall, which the mayor said was “very good for the tourist industry.”