GIOVE-B: Lost and Found

August 20, 2012 - By GPS World Staff

News courtesy of CANSPACE Listserv.

After more than four years of service as a Galileo test-bed satellite, GIOVE-B was retired on July 23. Its navigation transmitters were switched off and, according to an announcement from the European Space Agency, the satellite’s height was subsequently raised in a series of steps to place it in a so-called “graveyard” orbit where there will be no danger of it interfering with the operational Galileo satellites or other spacecraft.

After the first delta-V orbit manoeuvre, NORAD/JSpOC lost the satellite — at least NORAD/JSpOC stopped providing updated two-line orbital element sets for it. Eventually, 24 days later, the agency found it and resumed issuing element sets.

Just before the orbit manoeuvres, GIOVE-B had a mean motion of 1.70959839 orbits per day according to NORAD/JSpOC, which translates to an orbit semi-major axis value of approximately 29,544 kilometres. When NORAD/JSpOC recovered the satellite, its mean motion was 1.65377594 orbits per day with a semi-major axis of 30,205 kilometres, a change of 661 kilometres.