In space, even the tiniest objects can cause immense harm. To stay in low-Earth orbit, an object would typically be travelling at a whopping 27,000kph. At that speed, even just a stray bolt or broken bit of solar panel could punch a hole through the metal casing or the delicate inner circuitry of a working satellite. Space may be big—really big—but, as humans find new reasons to launch ever more satellites ever more cheaply, the bit of it just beyond the Earth’s atmosphere is getting busy.