The military aircraft tracker I built for an audience of one

At about half past eleven one evening this week I noticed a US Navy E-6B Mercury orbiting over the North Sea. Not “noticed” in the way of someone who happened to look up — I was on the sofa with a laptop balanced on one knee, and the orbit was being drawn for me, in slow careful circles, by a dashboard I had been building, in evenings and weekends, for the previous eight days. The aircraft is a survivable airborne command post for the strategic nuclear force. It does not normally show up on a flight tracker at all, and when it does, it tends to fly straight lines between US bases. An orbit over the North Sea at FL250 with the callsign blanked is not a routine sight. The dashboard, which I had taught about a hundred small things by then, had quietly composed the event for me as a “rare type” anomaly with a “long sortie” co-signal. I watched the orbit for about forty minutes. That feeling — the feeling of a system noticing something on my behalf — is the reason the project exists. It is…