Nation-states are blowing up satellites. Companies are launching megaconstellations of thousands of satellites. Dead rocket stages whiz around the planet for years. And yet, the International Space Station hasn’t been destroyed, payloads reach deep space unharmed, and we’re not trapped on Earth — at least not by debris. Either calamity is not upon us or we just don’t recognize it. Jon Kelvey takes the measure of Kessler Syndrome.