ASI - Agenzia Spaziale Italiana - Mission and Projects ASI - Agenzia Spaziale Italiana - Mission and Projects

ASI and the Galileo programme

The European satellite navigation system

Imagine a satellite navigation and tracking system entirely designed for civilian use that can offer a positioning accuracy of less than 10 cm, a precision never before achieved. 

A system that is not subject to the limitations or interruptions typical of other systems designed for military purposes, starting with the American GPS. 

With extraordinary potential for use in almost all sectors. Energy, land transport and maritime shipping, security, agriculture, finance: an almost unlimited range of applications and a capacity that revolutionizes the way in which we conceive certain ways of living and some of the services of which we are more accustomed. 

In a nutshell, this is the mission of the GALILEO program that, officially launched in 2003 - but conceived long before – by the Space Agency and the European Union with the important contribution of the ASI, is under construction.

An extraordinarily ambitious project then. Let’s take a brief look back over the history. Currently, the only satellite navigation and global positioning system actually in operation is the GPS (Global Positioning System) developed in the seventies in the United States for military purposes. 

There is also a similar former Soviet one, the GLONASS, the development of which was discontinued for some time: but the Russian Space Agency has recently resumed it and it is currently nearing completion. 

The GPS consists of 32 MEO satellites (Medium Earth Orbit) on six different orbital planes, some of which have fallen into disuse and others in reserve. The system has been operational since 1978 and available worldwide since 1994. 

The need to think of an alternative navigation system, as well as compatible with the GPS, is intrinsic in the very nature of the latter. 

Created to ensure the navigation of intercontinental missiles with nuclear warheads over the target to an accuracy of about 100 meters, the GPS - although eventually used for other purposes - is essentially a military instrument. 

The civil use instead imposes standards of precision on average much more accurate and cannot contemplate interruptions or limitations of services related to military needs of any type.

GALILEO will consist of thirty satellites when fully operational (27 operational and three in reserve) orbiting on 3 inclined planes on the equator (MEO, circular Medium Earth Orbit) at an  altitude of 23,222 km. 

The European Commission has already awarded contracts for the infrastructure: at present the cost is expected to be around 3.4 billion euro. The launch program, with Soyuz and Ariane rockets, began on October 21, 2011 with the departure of the first two satellites from Kourou in French Guyana and continued with the launch of the second pair, IOV3 and IOV4, in October 2012. 

In August 2013, began the testing phase of the PRS (Public Regulated Service), a service designed to provide high precision positioning data for the development of sensitive applications, designed for users expressly authorized by national governments. Belgium, France, Italy and the UK have recently performed tests of independent acquisition. Italy is the only country to have developed its own receiver, which confirmed during testing the usability of the signal based on the specifications provided by ESA. On 22 August 2014, the satellites number 5 and 6 of the constellation were launched with a Soyuz rocket from the European spaceport of Kourou in French Guiana at 12:27 GMT (14:27 CEST, 09:27 local time). Immediately after the first checks result is that the two satellites are positioned in an orbit slightly lower than expected.

The first four satellites constitute the minimum configuration required in order to validate the signal (phase "IOV"). Therefore it will be possible to begin to provide the first navigation services and proceed to test the full functionality of the space and ground segments.