Space debris: 130 million “poppy seed bullets flying around, punching holes in things”

Does sub-centimetre, non-trackable space debris pose an existential threat to satellites and orbital infrastructure? How can ultra-lightweight "black box" sensors turn a spacecraft's surface into an impact detector to diagnose anomalies? What do satellite operators need to unlock affordable, named-peril collision insurance through Lloyd's of London? And how can a "neighbourhood watch" network of sensor-equipped satellites build live space domain awareness to protect the space economy?