By Jonathan Amos
BBC News science reporter, Noordwijk
The in-orbit testing phase of Galileo, Europe's satellite-navigation system, will begin in December.
Giove-A will go up on a Soyuz-Fregat launch vehicle
The first demonstrator spacecraft will fly from Baikonur, Kazakhstan, on a Soyuz rocket on the 28th of the month.
The satellite, known as Giove-A, has the critical task of claiming the frequencies allocated to Galileo under international agreements.
To do this, the UK-built spacecraft must generate and transmit a timing and navigation signal by June 2006.
Galileo is Europe's biggest and most expensive space project. It will be independent of the American Global Positioning System (GPS) but interoperable with it.
Analysts expect the new constellation to drive a multi-billion-euro industry, creating perhaps 140,000 jobs.
Big and small
Being given such an important role in the project is a huge honour and something of a coup for Surrey Satellite Technology Ltd (SSTL), Giove-A's manufacturer.
The small company from Guildford has developed a speciality in rapid, low-cost satellite construction and has been handed the inaugural flight ahead of a consortium of some of Europe's biggest aerospace concerns.
WHAT IS GALILEO?
Europe's own global satellite navigation system
Will work alongside US GPS and Russian Glonass systems
Promises real-time positioning down to under a metre
Guaranteed under all but most extreme circumstances
Suitable for safety-critical systems - can run trains, guide cars and land planes
"We have delivered this spacecraft on time and at a fraction of the cost of conventional industry," explained Professor Martin Sweeting, the CEO of SSTL.
"There were a lot of people who recognised our expertise with microsatellites but who thought this might be beyond us. We didn't feel that and this is our vindication," he told the BBC News website.
Giove-A is currently undergoing final preparation at the European Space Agency's (Esa) technical centre, Estec, at Noordwijk, in the Netherlands.
It was here on Wednesday that Dutch Transport Minister, Ms Karla Peijs, officially named the spacecraft.
Up until this point, it had been referred to by its rather uninspiring project designation: the Galileo System Test Bed v2A, or GSTB-v2A for short.
Giove is Italian for Jupiter, the planet whose four major natural satellites Galileo Galilei used to develop a rudimentary form of navigation.
He realised that the formation of these moons, whose eclipses are frequent and visible, provided a "clock" whose face could be seen from every point on the Earth.
The 28m-euro (£20m), 600kg demonstrator will be the first European mission to fly in the high-radiation environment of medium-Earth orbit (MEO), at an altitude of 24,000km.
One of its goals, therefore, will be to assess how components cope in such conditions.
But more fundamentally, Giove-A will run a payload that includes two rubidium atomic clocks and a navigation signal generator capable of transmitting the codes and frequencies that will be used for Galileo.
The International Telecommunications Union has told the EU-Esa project that a signal of the correct structure must have been received on Earth by mid-2006 or the frequencies reserved for the venture could be handed to another party.
THE GALILEO FUTURE
Expected to be more than 400 million sat-nav users by 2015
European aerospace and electronics firms say it will create more than 100,000 jobs
Rescue services will be able to pinpoint the exact location of a car driver's accident
System will allow someone to find their way in an unfamiliar city using their mobile phone
It will deliver a system that will make national road-pricing a practical possibility
If something should go wrong with Giove-A, Esa has a back-up plan in GSTB-v2B (now known as Giove-B), another demonstrator built by the Galileo Industries consortium.
This will be launched in the New Year anyway - perhaps March or April - because it contains additional technologies not on the Surrey craft.
These include a hydrogen maser clock, one of the key components of the Galileo set-up that should allow top-level subscribers to know their position on the planet down to a few centimetres.
The first four satellites that will be used in the Galileo constellation proper have already been ordered and will fly in 2008-9. The remaining 26 will be sent up in batches to complete the network by the end of 2010.
Even with just one satellite in orbit from January, the Galileo service will, in essence, begin to operate.
Giove-A's signal will be fed into Egnos, an overlay system which can be used in Europe to improve the accuracy of GPS.
"The significance of Giove is to bring Galileo from a project to a reality," said Javier Benedicto, Esa's Galileo Project Manager.
"It is really the start of the operational phase of Galileo. I am sure that as of next year, you will find receivers in the shops which will have the label 'Galileo', because every signal you add to the GPS constellation has some benefit to the user," he told the BBC News website.
Giove-A will soon be packed up and sent to Baikonur
"Manufacturers around the world are already building GPS receivers with Galileo functionality in them."
Analysts expect there to be a rush of new applications based around the improved accuracy of the new system and the guarantees that come with the service.
The evidence, they say, can be seen in GPS itself which has already spawned a huge industry. And although the US government may have paid for the whole project with tax dollars, the returns in terms of new revenues for the American economy mean that investment has been repaid many times over.
"Although the Galileo system is going to cost 3-4bn euros in total, in a number of years' time the total market for satellite-navigation services and equipment is going to be 300bn on an annual basis," said Paul Verhoef, of the European Commission.
Hans Peter Marchlewski, from the Galileo Joint Undertaking, the company set up by the commission and Esa to drive Galileo's early phases, added: "Fifteen years ago, who would have expected that we could now not live without the PC? And in a couple of years' time, I expect we won't be able to live without the Galileo signals."