Salvaged Galileo Performs its First Navigation Fix

Artist’s view of Galileo Satellites 5 & 6. Photo: ESA/ J Huart

[Via Satellite 12-192014] Galileo’s fifth satellite, which was recently salvaged from the wrong orbit to begin navigation testing, has been combined with three of its predecessors to provide its very first position fix. This achievement is particularly significant because the fifth satellite is the first of a new design of 22 Galileos set to launch over the next few years.

Test receivers at ESA’s technical center in Noordwijk, the Netherlands, and at the Galileo In-Orbit Test station at Redu, Belgium received the signals at 12:48 GMT on Dec. 9 and fixed the satellites’ horizontal positions to better than 2 m. Further position fixes were then made by France’s CNES space agency in Toulouse, France. The following day, fixes were performed using Galileo’s Public Regulated Service, the encrypted highest-precision class of signal.

The fifth and sixth satellites were delivered into the wrong orbit by their Soyuz–Fregat rocket in August. The satellites’ shifting altitude left them unable to lock onto Earth for part of each orbit, preventing them from being used for navigation purposes. But, last month, a series of 11 maneuvers took the fifth satellite into a more circular orbit, some 3,500 km higher, allowing its navigation payload to be switched on for testing. A similar salvage operation is planned soon for its companion.