NavList:

Alan, you wrote:
"In plain English, all the fancy equipment, as sometimes happens, failed?"

Yep. And this was exactly the complaint raised 250 years ago. How could anyone trust a fallible machine to provide absolute time? Only damn fools would use chronometers, right? Well, no, obviously not. Navigators soon learned to trust incomprehensible machines --those "sea clocks" or "time keepers" or, eventually, "chronometers". But do you see that the same argument about "fancy equipment" applied to those intricate clocks? Chronometers were devices much like modern "smart" technology. They had a display from which the navigator could read the time and had little choice but to trust it. The internal workings were inaccessible to average users, and proper functioning had to be assumed. It's a close analogy to modern tech.

Q: How did the vast majority of the world's (ocean-going, scientific) navigators get to the point where they used chronometers and had no real backup technology?? 
A: The best backup to one chronometer is another chronometer. 

In the 21st century, the best backup to a satellite navigation device is another such device. If you only have one navigation system on your vessel and don't keep a smartphone or two stored away safely, then you're at risk and un-necessarily so. As for the backup to the GPS satellite signals themselves, it's Glonass/Galileo/Beidou. These exist now, today, and if you have any so-called "GPS" device, like a smartphone, it is almost certain that you are already backed up. The backup to Galileo? It's GPS/Glonass/Beidou. That's why this Galileo outage is only a terrible embarrassment for the European system and not a crisis. Any smartphone that had been set to prefer Galileo signals (which would be rare in the first place) simply reverted to GPS and Glonass (with a dash of Beidou) when the Galileo signals turned off. Of end users, greater than 99.99% saw not even a hint that their positioning system had switched to backup. Isn't that a key property of an excellent backup? No one knew there was a problem until the media picked up on it!

Of course any outage is a disaster for the people who are responsible for the system. The Galileo team looks incompetent this week. All those non-GPS alternative systems better learn the high-quality management lessons from the US GPS system. Reliability is key, even when you have backups.

Frank Reed