A demonstrator spacecraft for Europe's proposed Galileo Mission to prove Europe's sat-nav ...
EU approves Galileo satellite navigation program ...
Galileo demo sat to be despatched ... satellite navigation system has launched from Kazakhstan.

The Giove-B satellite was taken into space atop a Soyuz rocket which left Earth at 2216 GMT, Saturday.

The demonstrator will test the key technologies which will eventually be built into the 30 operational platforms that form the Galileo network.

These include the atomic clocks which provide the precise timing that underpins all sat-nav applications.

It is an important moment for Galileo which has suffered severe delays.

Europe has already spent 1.6bn euros ($2.5bn; £1.3bn) on the project and ministers have warned that the additional 3.4bn euros ($5.3bn; £2.7bn) recently approved for sat-nav investments will be the limit on expenditure.

Galileo is envisaged as being technologically complementary to GPS, and is touted as a key high-technology venture for the EU.

It is designed to improve substantially the availability and accuracy of timing signals delivered from space.

Users should get quicker, more reliable fixes and be able to locate their positions with an error of one metre compared with the current GPS error of several metres.

Giove-B is the second demonstrator satellite to go into orbit following the launch of Giove-A in 2005. The first mission met international obligations to claim the frequencies Galileo will use to transmit its signals to receivers on the ground.

This second mission flies a spacecraft which is, to a large degree, a template for the 30 operational platforms that will follow.

"We're already cutting metal on the first four of those," said Richard Peckham, from EADS Astrium, which has led the development of the demonstrator.

"Giove-B is therefore a significant step in that direction. There are new technologies in Europe which haven't yet flown. This is the opportunity to test their performance in space," he told BBC News.

A fundamental focus for Giove-B will be the in-orbit behaviour of its passive hydrogen maser clock.

It is the most stable clock ever put in permanent orbit, and is designed to keep time with an accuracy of better than one nanosecond (billionth of a second) in 24 hours.

As well as its atomic clocks (Giove-B carries three clocks), the latest demonstrator will test the generation of signals across the full spectrum Galileo intends to use for its five sat-nav services.

"It is the firm intention of Galileo to improve what GPS is providing now but also to be compatible," explained Javier Benedicto, Galileo project manager at the European Space Agency (Esa).

"Currently GPS operates with one open signal in a particular frequency band. With Galileo, we are going to broadcast up to 10 signals and the combination of these signals will allow us to provide a number of services which we cannot achieve today with the current system."

If all of these technologies work as predicted, the project will be clear to launch the first four operational satellites in 2010.

Full capability has been set for the end of 2013.

(BBC)

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