All is according to plan – Galileo constellation became increased for two satellites.
These two navigation satellites were launched on atop of Soyuz-2.1a with Fregat-MT on December 17, 2015, at 12:52 GMT. It was last Galileo mission in 2015; satellites were designed and manufactured by OHB System with SSTL as main contractor for payload. Procedure of commissioning which have just been finished, assumed performing various tests of navigational equipment with special emphasis on accuracy. Test were performed from ESA ground station in Redu, Belgium; Dish antenna with diameter at 20 m, which stands in Redu, was used to perform most detailed analysis of navigational signal received from satellites. Tests of navigation equipment gave also possibility to check if satellites are in good health – all tests of accuracy were performed in the cooperation with Galileo Control Center in Oberbfaffenhofen in Germany which is responsible for controlling satellite platform. During tests also Control Center in Fucino, Italy, which covers providing service to the users, was engaged. FOC-FM9 and FOC-FM8 are second pair of Galileo satellites which started service this year – in February FOC-FM6 and FOC-FM7 were successfully commissioned.
FOC satellites are medium weight (at 717 kg) with dimensions at 2.7 m x 1.2 m x 1.1 m. They are equipped with two solar arrays with total span of 14.67 m and are providing 1900 W of power. Satellites are able to remain operational for 12 years. Propulsion of the satellites is eight NARC-1 thrusters fueled with hydrazine and providing thrust at 1N. Main onboard instruments are: four clocks (two based on rubidium, two based on hydrogen maser), navigational signal transponders operating on E5, E6 and E1 band. Satellites are also equipped in additional payload which is COSPAS/SARSAT satellite maritime rescue system.
Next launch of Galileo satellites (FOC-10 and FOC-11) is scheduled for 24th May 2016 from Guiana Space Center on atop of Soyuz-2.1a.
On picture above: launch performed from Guiana Space Center seen from International Space Station.