The first Galileo demonstrator is put orbit as per the plans for a fully
operable new global navigation satellite system, under a partnership between ESA
and the European Commission. Giove A, the first Galileo in-orbit validation
element, was launched on 28th Dec. 2005 from Baikonur, Kazakhstan, atop a Soyuz-Fregat
vehicle operated by Starsem. Following a perfect lift-off at 05:19 UTC (06:19
CET), the Fregat upper stage performed a series of manoeuvres to reach a
circular orbit at an altitude of 23 258 km, inclined at 56 degrees to the
Equator, and deployed the satellite at 09:01:39 UTC (10:01:39 CET).
This 600 kg satellite, built by Surrey Satellite Technology Ltd (SSTL) of
Guildford, in the UK, has a threefold mission. First, it will secure use of the
frequencies allocated by the International Telecommunications Union (ITU) for
the Galileo system. Second, it will demonstrate critical technologies for the
navigation payload of future operational Galileo satellites. Third, it will characterize
the radiation environment of the orbits planned for the Galileo constellation.
Formerly known as GSTB-V2/A (Galileo System Test Bed Version 2), Giove A
carries two redundant, small-size rubidium atomic clocks, each with a stability
of 10 nanoseconds per day, and two signal generation units, one able to generate
a simple Galileo signal and the other, more representative Galileo signals.
These two signals will be broadcast through an L-band phased-array antenna
designed to cover all of the visible Earth under the satellite. Two instruments
will monitor the types of radiation to which the satellite is exposed during its
two year mission.
The satellite is under the control of SSTL’s own ground station. All
systems are performing well, the solar arrays are deployed and in-orbit checkout
of the satellite has begun. Once the payload is activated, the Galileo signals
broadcast by Giove A will be carefully analyzed by ground stations to make sure
they satisfy the criteria of the ITU filings.
Giove B, a second demonstrator satellite, built by the European consortium
Galileo Industries, is currently being tested and will be launched later. It is
due to demonstrate the Passive Hydrogen Maser (PHM), which, with a stability
better than 1 nanosecond per day, will be the most accurate atomic clock ever
launched into orbit. Two PHMs will be used as primary clocks onboard the
operational Galileo satellites, with two rubidium clocks serving as backups.
Subsequently, four operational satellites will be launched to validate the
basic Galileo space and related ground segments. Once this In-Orbit Validation (IOV)
phase is completed, the remaining satellites will be launched to achieve Full
Operational Capability (FOC).
Galileo will be Europe’s own global navigation satellite system, providing
a highly accurate, guaranteed global positioning service under civilian control.
It will be inter-operable with the US Global Positioning System (GPS) and Russia’s
Global Navigation Satellite System (Glonass), the two other global satellite
navigation systems. Galileo will deliver real-time positioning accuracy within a
meter, not currently offered by any other GPS system for civilian use.
Applications planned for Galileo include positioning and derived value-added
services for transport by road, air and sea, rail, fisheries and
agriculture, oil prospecting, civilian protection activities, construction,
public works and telecommunications.
For further information, please contact:
ESA Media Relations Division