The European Space Agency and launch company Arianespace on Monday said they had signed a contract for the launch of four testbed satellites in Europe’s Galileo sat-nav system.
The satellites will be launched in pairs by two Russian-made Soyuz launchers from ESA’s space centre at Kourou, French Guiana, in the second half of 2010, they said. Financial details were not given.
The first satellites comprise "in-orbit validation" at a circular altitude of 23,000 kilometers (14,375 miles) from Earth to test Galileo’s technology.
The announcement was made at the start of the Paris Air Show at Le Bourget airport.
Arianespace markets satellite launches with ESA’s Ariane-5 and is equipping Kourou with facilities to launch the medium-range Soyuz and a light rocket called Vega.
Galileo, budgeted at 3.4 billion euros, is expected to be operational from 2013 as a rival to the US GPS and Russia’s GLONASS system.
Two test satellites, Giove-A and Giove-B, were launched in December 2005 and April 2008, to meet international requirements to reserve radio frequences and to check out experimental technology. When fully operational, Galileo will use as many as 30 satellites.