Galileo (satellite navigation)

Galileo is a global navigation satellite system (GNSS) created by the European Union through the European Space Agency (ESA) and operated by the European Union Agency for the Space Programme (EUSPA). It is headquartered in Prague in Czechia, with two ground operations centres in Oberpfaffenhofen, Germany (mostly responsible for the control of the satellites), and in Fucino, Italy (mostly responsible for providing the navigation data). The €10 billion project began offering limited services in 2016. It is named after the Italian astronomer Galileo Galilei.

One of the aims of Galileo is to provide an independent high-precision positioning system so European political and military authorities do not have to rely on the United States GPS or the Russian GLONASS systems, which could be disabled or degraded by their operators at any time. The use of basic (lower-precision) Galileo services is free and open to everyone. A higher-precision service is available for free since 24 January 2023, previously only available to government-authorized users. Galileo is also to provide a new global search and rescue (SAR) function as part of the MEOSAR system.

The second Galileo test satellite GIOVE-A was launched 28 December 2005, while the first satellite to be part of the operational system was launched on 21 October 2011. Galileo started offering Early Operational Capability (EOC) on 15 December 2016, providing initial services with a weak signal. In October 2018, four more Galileo satellites were brought online, increasing the number of active satellites to 18. In November 2018, the FCC approved use of Galileo in the US. As of September 2024, there are 25 launched satellites that operate in the constellation. It is expected that the next generation of satellites will begin to become operational after 2026 to replace the first generation, which can then be used for backup capabilities. Most satellites of the programme were built by OHB in Bremen, Germany, with the contribution of Surrey Satellite Technology (SSTL) in Guildford, United Kingdom.

The Galileo system has a greater accuracy than GPS, having an accuracy of less than 1 m when using broadcast ephemeris (GPS: 3 m) and a signal-in-space ranging error (SISRE) of 1.6 cm (GPS: 2.3 cm) when using real-time corrections for satellite orbits and clocks.

In 2008, the different concepts of the three main contributors of the European Space Agency (ESA) (Germany, France and Italy) for Galileo were compared and reduced to one by a joint team of engineers from all three countries. The first stage of the Galileo programme was agreed upon officially on 26 May 2003 by the European Union and the ESA. The system is intended primarily for civilian use, unlike the more military-focused systems of the United States (GPS), Russia (GLONASS) and China (BeiDou) in that Galileo doesn't limit accuracy for non-military applications. The European system could be subject to shutdown for military purposes in extreme circumstances (such as an armed conflict). Italy and Germany led the development of the first generation of the Galileo programme, while France is playing a more prominent role in the development of the Galileo Second Generation (G2G).

The European Commission had some difficulty funding the project's next stage, after several allegedly "per annum" sales projection graphs for the project were exposed in November 2001 as "cumulative" projections, which for each year projected included all previous years of sales. The attention that was brought to this multi-billion euro growing error in sales forecasts resulted in a general awareness in the commission and elsewhere that it was unlikely that the programme would yield the return on investment that had previously been suggested to investors and decision-makers.^{[better source needed]} On 17 January 2002, a spokesman for the project stated that, as a result of US pressure and economic difficulties, "Galileo is almost dead".

A few months later, however, the situation changed dramatically. European Union member states decided it was important to have a satellite-based positioning and timing infrastructure that the US could not easily turn off in times of political conflict.

The European Union and the European Space Agency agreed in March 2002 to fund the project, pending a review in 2003 (which was completed on 26 May 2003). The starting cost for the period ending in 2005 is estimated at €1.1 billion. The required satellites (the planned number is 30) were to be launched between 2011 and 2014, with the system up and running and under civilian control from 2019. The final cost is estimated at €3 billion, including the infrastructure on Earth, constructed in 2006 and 2007. The plan was for private companies and investors to invest at least two-thirds of the cost of implementation, with the EU and ESA dividing the remaining cost. The base Open Service is to be available without charge to anyone with a Galileo-compatible receiver, with an encrypted higher-bandwidth improved-precision Commercial Service originally planned to be available at a cost, but in February 2018 the high accuracy service (HAS) (providing Precise Point Positioning data on the E6 frequency) was agreed to be made freely available, with the authentication service remaining commercial. By early 2011 costs for the project had run 50% over initial estimates.