Galileo IOV Satellites Reach Operating Orbits

November 28, 2011  - By

News from CANSPACE Listserv.

An announcement from ESA on November 4 stated "Europe’s first two Galileo IOV satellites have reached their final operating orbits, opening the way for activating and testing their navigation payloads." But, based on NORAD/JSpOC tracking of the satellites, it seems that the final orbits were achieved only a day or so ago.

The plot above (and linked here) shows the mean motion (mm) of the PFM and FM2 satellites since launch. As evidenced by the lengthy gaps in the mm history, it is clear that NORAD/JSpOC sometimes has difficulty in reacquiring satellites after delta-V manoeuvres. We do know, however, that both satellites have appeared to reach their final orbits sometime between November 19 and 23. The mm values are now very close to the value 1.7046556 orbits per day derived from the mean semimajor axis of the Galileo constellation as given in the Galileo Open Service Signal-In-Space Interface Control Document: 29601.297 km.

The arguments of latitude of the two satellites, essentially in the same orbit plane, are now 40 degrees apart as intended. There have not been any public reports that navigation signals from the satellites have yet been switched on.

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