ESA Retires GIOVE-B After Four Years Of Service
July 25, 2012

ESA Retires GIOVE-B After Four Years Of Service

Lee Rannals for - Your Universe Online

The European Space Agency (ESA) announced on Tuesday that it has retired its GIOVE-B experimental navigation satellite.

The satellite initiated a thruster firing yesterday, raising GIOVE-B's orbit by about 18 miles, taking it steps closer to a satellite graveyard up in orbit.

More thruster firings will take place in the next three weeks, so that by mid-August the experimental satellite will be 372 miles above its original orbit.

GIOVE-B, or the second "Galileo In-Orbit Validation Experiment," launched on April 27, 2008, carrying both types of atomic clocks being used by the Galileo system into orbit. These clocks included a rubidium clock, which is accurate to three seconds in one million years, and a passive hydrogen maser, which is accurate to one second in three million years.

The satellite was also fitted with an antenna to illuminate Earth with its test signal, which was linked to a signal generation unit able to produce the kind of complex modulated signals that are required for the interoperation of Galileo with the U.S. GPS system.

ESA said that GIOVE-B carries the space agency's advanced Standard Radiation Monitor to survey the radiation environment in its orbit.

ESA turned off GIOVE-B's payload on Monday, preparing it for its thruster firings to its final resting place.

“GIOVE-B, like its predecessor GIOVE-A, performed excellent work testing Galileo hardware, securing Europe´s rights to the radio frequencies set aside for Galileo and gathering data on medium-Earth orbit conditions,” Valter Alpe, managing the GIOVE satellites for ESA, said. “Its signal, in combination with its ground element, also served to prove the Galileo system will work as planned."

He said that now that the first Galileo satellites have jumped into orbit, and are operating correctly, there is no need for the GIOVE satellites any more.

GIOVE-A was launched on December 28, 2005, and it ended its career in orbit in August 2009. It now lies waiting for GIOVE-B to join it in the dedicated orbit in space for retired satellites.