UPDATE: All satellites currently in operation appear to be back online, although some instability is expected
The European Union's satellite navigation infrastructure, used by businesses and government agencies across the continent, has been offline for more than 100 hours following a network-wide outage.
The Global Navigation Satellite Systems Agency (GSA), which runs the 8 billion Galileo programme, confirmed this weekend the satellite system has been struck with a "technical incident related to its ground infrastructure".
As a result, all 24 satellites in orbit are non-operational.
"Experts are working to restore the situation as soon as possible," the GSA said in a statement.
"An Anomaly Review Board has been immediately set up to analyse the exact root cause and to implement recovery actions."
Galileo is used by government agencies, academics and tech companies for a wide range of applications, from smartphone navigation to search-and-rescue missions.
The programme offers several services including a free Open Service for positioning, navigation and timing, and an encrypted Public Regulated Service (PRS) for government-authorised users like customs officers and the police.
Its business application spans multiple sectors; used by fishing vessels, for example, to provide data to fishery authorities as well as by tractors with guidance for navigation. According to the GSA, 7.5 billion Galileo-friendly apps are expected by the end of 2019.
However, the satellite system, developed so European organisations aren't wholly entirely reliant on GPS, has been offline since 1 am UTC on Thursday 11 July.
The GSA said at the time that users may experience "service degradation" on all Galileo satellites. A further update then issued two days later claimed users would be experiencing a total service outage until further notice. Neither update offered a concrete explanation for the mysterious outage, which has persisted at the time of writing.
The root cause, however, may lie with a ground station based in Italy, known as the Precise Timing Facility (PTF), according to Inside GNSS. This facility generates the Galileo System Time, which is beamed up to the satellites to enable user localisation. It is also often used as an accurate time reference.
In June, GPS services were also hit by a similar outage which affected a host of Middle-Eastern countries. According to Israeli media, that outage was linked to state-sponsored attacks from Russia.
The government and UK businesses have played an integral role in helping to develop Galileo since its pilot launch in 2016. The continental service is expected to be fully operational by 2020, with 30 satellites in total.
But the UK's withdrawal from the EU has threatened to fully cut off access by British agencies and companies, should no deal be agreed.
The government has already set aside 92 million to develop an independent satellite system, although it's unclear how long this would take to implement.
