The Department of Defense lets NASA sweat the small stuff, though. The space agency formed its Orbital Debris Program Office in 1979, and that office is responsible for characterizing objects too small to be tracked by the Air Force but big enough to cause problems. NASA uses two radar systems operated by MIT’s Lincoln Laboratory for about 1,000 hours a year to understand the population of millimeter-to-centimeter-sized objects in low-Earth orbit. That schedule that will likely get busier, along with the number of close encounters.

Space Jam

Just how much bigger will the problem get? SpaceX alone plans to send up nearly 12,000 small internet-beaming objects over time. OneWeb has designs on some 700 similar sats. Planet just launched around 100 that take pictures of the Earth’s entire landmass every day. And those are just the heaviest hitters. Little orbiters—especially the smallest types, CubeSats and NanoSats—are within reach of research scientists, government agency experiments, smaller companies, and even individual humans. Take the private Breakthrough Starshot project, which eventually plans to send diminutive spacecraft to Alpha Centauri star system (really). It just launched six "Sprites": the world's smallest satellites, measuring 3.5 centimeters on a side.

All of those satellite operators are in charge of making sure what they sent up comes back down, in a timely way. Bigsat operators can just use the last of their fuel to plunge their darlings toward the ocean. But many smallsats, especially the smallest kinds, don’t have propulsion systems. To naturally “de-orbit” fast, they have to be in an orbit that naturally decays quickly—an ellipse in which atmospheric drag drags them back to Earth fast.

Some smallsat operators are planning to put propulsion systems aboard. Great! But that poses another problem: explosions. If there’s pressurized fuel, there’s always the possibility for paroxysm. Which means more debris. And problematically, most members of a given smallsat constellation have the same exact specs—and so the same flaws. If one sat's propulsion system has critical personality defects, so too do its identical siblings. When that happens with cars, automakers recall them. When that happens in space, a bunch of satellites can explode. And that's not just true for their movement-making parts: It's also true of satellite batteries. Just ask Samsung.

The international timeline for self-destruction, originally set by NASA’s Orbital Debris Program Office, is that 25 years after the operational life of a satellite ends, it should burn up in the atmosphere. That's the goal for new launchers, to limit how much bigger they make the pile of space trash. NASA calls it "mitigation."

But you can't admonish all those bolts and rocket cores and paint chips and, you know, junk that's already out there. And you can't guilt non-operational satellites into getting down from there (you can take them down, but more on that later). The idea, at this point, is just to make what's bad only as worse as necessary.

On top of that, countries don't have to enforce the 25-year guideline. In 2015, 35 percent of satellites were out of compliance. Of all CubeSats, specifically, launched between 2003 and 2014, a fifth didn’t meet the criteria. Know why? It's hard. It costs money. And, for the most part, no one makes them do it.

There's good news, though, for at least the heftiest of the coming smallsat herds: "Both SpaceX and OneWeb have indicated at that end of the operation of their spacecraft, they plan to lower the orbits so the orbits will naturally decay in [less than] five years rather than 25 years,” says the program's J.C. Liou. But that still leaves unregulated rogues up there, endlessly circling, dead and dangerous.

Space and Space Nets to the Rescue

Slacker satellites—ones that haven't prepared for mitigation—get a bit of a reprieve, thanks to some quirky orbital properties. “Like a river, like the atmosphere, space can clean itself,” says Lisa Ruth Rand, a science historian writing a book about space junk. During solar maximum, which happens every 11 years, the thermosphere heats up and expands, pressing its particles against objects in near-space, where many small satellites operate. That creates extra friction. “It drags them back to the atmosphere,” says Rand.