GPS Rival Comes Closer To Fruition

The second test satellite under Europe's Galileo program launched successfully in the early morning hours Sunday, giving the European Space Agency a needed boost with its efforts to establish a satellite navigation system to rival GPS.

The Galileo In-Orbit Validation Element satellite (GIOVE-B) was lofted into a medium altitude orbit by a Soyuz/Fregat rocket, launched from Baikonur cosmodrome in Kazakhstan by launch operator Starsem. Lift-off occurred at 0416 local time April 27. The Fregat upper stage safely delivered the satellite into an Equatorial orbit three hours and 45 minutes later.

"With the successful launch of GIOVE-B, we are about to complete the demonstration phase for Galileo," said ESA Director General Jean Jacques Dordain. "The strong cooperation between ESA and the European Commission has been instrumental in making progress in a difficult environment over the past few years; and, even with that being so, Galileo has already materialized, with two satellites now in orbit, significant headway made on the next four (already in the construction phase) and a fully qualified EGNOS service -- all this designed to serve citizens in Europe and all around the globe. ESA will begin shortly the procurement process for the overall constellation beyond IOV under EC responsibility."

Like its GIOVE-A predecessor, GIOVE-B carries two redundant small-size rubidium atomic clocks, each with a stability of 10 nanoseconds per day. It also features an even more accurate payload: the Passive Hydrogen Maser (PHM), with stability better than one nanosecond per day. The first of its kind ever to be launched into space, this is now the most stable clock operating in earth orbit, according to ESA.

Two PHMs will be used as primary clocks onboard operational Galileo satellites, with two rubidium clocks serving as back-up. GIOVE-B also incorporates a radiation-monitoring payload to characterize the space environment at the altitude of the Galileo constellation, as well as a laser retroreflector for high-accuracy laser ranging.

In addition to its technology-demonstration mission, GIOVE-B will also take over GIOVE-A's mission to secure the Galileo frequencies, as that first Galileo demonstration satellite launched in December 2005 is now approaching the end of its operational life.

Beyond GIOVE-B, the next step in the Galileo program will be the launch of four operational satellites, to validate the basic Galileo space and related ground segment, by 2010. Once that In-Orbit Validation (IOV) phase is completed, the remaining satellites will be launched and deployed to reach the Full Operational Capability (FOC), a constellation of 30 identical satellites.

Galileo will be Europe's very own global navigation satellite system, providing a highly accurate, guaranteed global positioning service under civil control. Though designed to be fully interoperable with the current US Global Positioning System (GPS) and Russia's GLONASS, ESA intends Galileo to deliver much closer real-time positioning accuracy.

Numerous applications are planned for Galileo, including positioning and derived value-added services for transport by road, rail, air and sea, fisheries and agriculture, oil-prospecting, civil protection, building, public works and telecommunications.

FMI: www.esa.int