Europe's satellite navigation system has been broken for days, after a disastrous technical incident.
Most of the satellites that power the Galileo system are broken, leading to a service outage across the positioning system.
It means that users will have to automatically switch over to the US Global Positioning System that it was intended to replace.
But enough of the service is working that it will still be able to find people in emergencies, one of its key roles.
Experts are working to restore operations of the multibillion euro programme, the European Global Navigation Satellite Systems Agency (GSA) said on Sunday.
Galileo began testing in December 2016 as an alternative to the US-made Global Positioning System (GPS), designed to provide an exact location to commercial and government customers, with a full deployment expected in 2020.
The agency's status page shows 22 satellites in the Galileo constellation as "not usable" due to service outage.
"The cause of the technical incident is identified and recovery actions are implemented to ensure that the nominal service is resumed as soon as possible while safeguarding quality of the services," the GSA said.
In November, Britain gave up on efforts to gain access to the EU's Galileo satellite navigation system for defence and critical national infrastructure purposes, after being frozen out by Brussels because of Brexit.
It is unclear whether the UK will get back the £1.2 billion it sank into Galileo.
Instead, it is aiming to build its own Global Navigation Satellite System, at a cost estimated by independent experts at £3 billion to £5 billion.
Additional reporting by agencies