Galileo now has two more satellites
On 10 August, the European GNSS Agency (GSA) officially announced that two more satellites had gone into operation in the Galileo constellation, the European global navigation satellite system (GNSS) for civilian use, thus bringing the total number of satellites currently available for the service to 18. More precisely, they are satellites GSAT0212-SV ID 03 and GSAT0213-SV ID 04 which, having completed the in-orbit testing (IOT) phase, are joining the other two satellites GSAT0207-SV ID 07 and GSAT02014-SV ID 05 (officially in service since 31 May 2017). The four satellites were launched together on 17 November 2016 from the European space station at Kourou in French Guiana, the first on board an Ariane 5 launcher.
The Galileo system, already in service from December 2017, will be fully operational by the end of 2020 with a constellation of 30 satellites in orbit (24 in full service and 6 spares). Compared to the other two global navigation systems (America’s NAVSTAR and Russia’s GLONASS), it will guarantee excellent coverage of the Earth up to latitudes 75° North (beyond the North Cape) since the satellites are placed on three circular Medium Earth Orbits (MEO), at an angle of 56° to the Equator, and at an altitude of 23,222 km.
One of Galileo’s main features is interoperability with America’s NAVSTAR and Russia’s GLONASS, allowing users to read their position from three systems (about 60 satellites in total) using the same receiver and considerably increasing accuracy as well as availability and continuity of the service.
Four more satellites are scheduled to be launched over the coming months, thus increasing the total number of satellites available for the Galileo system to 22.
by Enzo Scasciamacchia
To find out more:
- Time-lapse video of the Galileo 15, 16, 17 and 18 satellites, from final preparation to lift-off on 17 November 2016 on board the Ariane 5 launcher
- Countdown for the Galileo 15, 16, 17 and 18 satellites