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View Full Version : ESA's most advanced navigation satellite launched tonight (Forwarded)


Andrew Yee[_1_]
April 28th 08, 04:31 PM
European Space Agency
Press Release No. 25-2008
Paris, France 27 April 2008

ESA's most advanced navigation satellite launched tonight

A further step towards the deployment of Europe's Galileo global navigation
satellite system was taken tonight, with the successful launch of ESA's
second Galileo In-Orbit Validation Element (GIOVE-B) satellite, carrying the
most accurate atomic clock ever flown into space.

The GIOVE-B satellite was lofted into a medium altitude orbit around the
earth by a Soyuz/Fregat rocket departing from the Baikonur cosmodrome in
Kazakhstan by launch operator Starsem. Lift-off occurred at 04:16 local time
on 27 April (00:16 Central European Summer Time [2216 UTC April 26]). The
Fregat upper stage performed a series of manoeuvres to reach a circular
orbit at an altitude of about 23 200 km, inclined at 56 degrees to the
Equator, before safely delivering the satellite into orbit some 3 hours and
45 minutes later. The two solar panels that generate electricity to power
the spacecraft deployed correctly and were fully operational by 05:28 CEST
[0328 UTC].

This 500 kg satellite was built by a European industrial team led by Astrium
GmbH, with Thales Alenia Space performing integration and testing in Rome.
Two years after the highly successful GIOVE-A mission, this latest satellite
will continue the demonstration of critical technologies for the navigation
payload of future operational Galileo satellites.

Three high-accuracy space clocks aboard

Like its predecessor, GIOVE-B carries two redundant small-size rubidium
atomic clocks, each with a stability of 10 nanoseconds per day. But it also
features an even more accurate payload: the Passive Hydrogen Maser (PHM),
with stability better than 1 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. 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 characterise the
space environment at the altitude of the Galileo constellation, as well as a
laser retroreflector for high-accuracy laser ranging.

Signal generation units will provide representative Galileo signals on three
separate frequencies broadcast via an L-band phase array antenna designed to
entirely cover the visible earth below the satellite.

The satellite is now under the control of Telespazio's spacecraft operations
centre in Fucino, Italy, and in-orbit checking-out of the satellite has
begun.

Final demonstration before Galileo

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 programme 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.

"With the successful launch of GIOVE-B, we are about to complete the
demonstration phase for Galileo," said ESA Director General Jean Jacques
Dordain in Fucino while congratulating the ESA and industrial teams. "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 materialised, 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."

Galileo will be Europe's very own global navigation satellite system,
providing a highly accurate, guaranteed global positioning service under
civil control. It will be interoperable with the US Global Positioning
System (GPS) and Russia's GLONASS, the two other global satellite navigation
systems. Galileo will deliver real-time positioning accuracy down to the
metre range with unrivalled integrity.

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.

(*) Note for Editors: European Geostationary Navigation Overlay Service.
EGNOS is a joint programme being carried out by the European Space Agency,
the European Commission and Eurocontrol. It comprises a network of more than
forty elements all over Europe that collect, record, correct and improve
data from the US Global Positioning System. The modified signals are then
relayed via geostationary satellites to user terminals, offering positional
accuracy better than two metres, compared with 15 to 20 metres for GPS
alone. In addition, EGNOS provides a guarantee of signal quality that GPS
does not.

For further information:

ESA Media Relations Office
Communication and Knowledge Department
Phone + 33 1 53 68 72 99

[NOTE: An image and weblinks supporting this release are available at
http://www.esa.int/esaCP/SEM9GD2QGFF_index_1.html ]