What Happens If GPS Goes Dark?

By Michael Bath · October 2026 · The world of The Refuge, explained

In The Refuge, the first sign isn’t the lights going out. It’s the little blue dot on every phone that stops moving. Most of us think of GPS as a map. It is also a clock, and the clock is the part the modern world leans on hardest.

A clock in the sky

Every GPS satellite carries atomic clocks and broadcasts the time it keeps. A receiver works out where it is by comparing how long those signals took to arrive. But you don’t have to be lost to use GPS. Cell networks, power grids, banks and data centers take the same signal for a different reason: it lets their equipment, spread across a whole country, agree on exactly what “now” is, down to millionths of a second.

What stops first

Getting around. Phones, delivery routes, trucks, ships and aircraft lose their easiest way of knowing where they are. People fall back on memory, road signs and paper maps, if they still have them.

Help arriving. Emergency services lean on location: finding a caller, sending the nearest ambulance, guiding it there. In the UK government’s study of an outage, emergency services were the single largest loss.

The quiet timing. Well-run networks keep backup clocks that can hold the time on their own for a while. The longer an outage lasts, the more of those backups drift, and the more systems that depend on agreeing with each other begin to stumble.

The fields. Modern farming steers tractors and plants seed by satellite. An outage in planting season costs more than one in winter.

What a day without it would cost

A study by RTI International for the U.S. National Institute of Standards and Technology estimated that losing GPS would cost the American economy about $1 billion a day, and possibly more during planting season. In the UK, a report for the government put a 24-hour, nationwide loss of satellite navigation at £1.4 billion, and a seven-day loss at about £7.6 billion. Emergency services, roads and shipping made up almost nine-tenths of it.

It has happened, on a smaller scale

In July 2019, Galileo, Europe’s own satellite navigation system, went down for about a week after a failure in the ground systems that keep its satellites’ clocks and orbits up to date. Most phones barely noticed, because they listen to GPS as well. That is the real lesson: the safety net is having more than one system, and more than one way of doing things.

Where the novel takes liberties

Here is the honest part. GPS satellites fly about 20,000 kilometers up, far above the crowded low orbits where a Kessler cascade would begin, and the system has spares and backups. A real outage would more likely be partial, local or brief. The Refuge asks what happens if all of it went at once, because that is where the human story lives: neighbors who know the back roads, a family that kept a paper map in the glove box, a community that remembers how to find its way without being told.

Sources: RTI International for NIST, Economic Benefits of the Global Positioning System (GPS) (2019); London Economics for the UK government, The economic impact on the UK of a disruption to GNSS (published October 2023); reporting on the July 2019 Galileo outage. Related: What is a Kessler cascade?