ASM
2nd Galileo Satellite Up
A Soyuz/Fregat rocket lifted the second Galileo engineering test bed from the Baikonur cosmodrome in Kazakhstan on 27 April.
The European Space Agency’s second In-Orbit Validation Element satellite, Giove-B, is carrying what ESA describes as the most accurate atomic clock ever flown in space.
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, before seperating from the satellite.
The 500 kg satellite was built by a European industrial team led by Astrium GmbH, with Thales Alenia Space performing integration and testing in Rome.
Following on from the Giove-A mission, this latest satellite will continue the demonstration of critical technologies for the navigation payload of future operational Galileo satellites.
Like its 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, a passive hydrogen maser, with a stability better than 1 nanosecond per day. Assuming the cosmological models most popular with astronomers, this clock will be in error by less than a second at the end of the universe.
Two of these will be used as primary clocks onboard operational Galileo satellites, with two rubidium clocks serving as backup.
The next step in the Galileo program will be the launch of four operational satellites by 2010 to validate the basic Galileo space and related ground segment. Once that is completed, the remaining satellites will be launched and deployed.
The Europeans expect to reach the full operational capability of 30 satellites by 2012-13.
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