Successful Galileo launch
12 December saw 4 more Galileo satellites join the constellation.
Galileo satellites 19-22 were launched at 1836 UTC (1536 local) on 12 December by an Ariane 5 heavy launcher from the Guiana Space Center (CSG), Kourou, French Guiana. This was the 9th Galileo launch from CSG and the second using the Ariane 5 ES launcher; previous launches had been in satellite pairs, using Soyuz launchers.
The first pair of 1,576 lb (715 kg) satellites was released ~3 h 36 m after liftoff, with the second pair 20 minutes later. They were released into their target 12,377 NM (22,922 km) medium Earth orbits (MEO) inclined at 57º; over the next few days they will be manoeuvred into their final working orbits at 12,539 NM (23,222 km) altitude. They will then begin ~6 months of tests performed by the European Global Navigation Satellite System Agency (GSA) before joining the operational constellation.
The satellites were built in Germany by OHB Systems, with UK-based Surrey Satellite Technology Ltd (SSTL) providing the navigation payload. Planned satellite operational lifetime is 12 years.
This mission brings the Galileo system up to 22 satellites:
- 14 usable
- 2 not available (clock problems)
- 2 under 'testing' (wrong orbits)
- 4 just launched
Initial Services (IS) began on 15 December 2016 - Galileo satellites can be used within multi-constellation fixing, but do not give worldwide cover themselves. Full Operational Capability (FOC), with Open Service (OS), Public Regulated Service (PRS) and Search & Rescue Service (SARS), is scheduled for 2020.
A last Ariane 5 launch will orbit 4 more Galileo satellites in 2018, then Ariane 6 will take over in 2020-21.
Image from ESA. Details from the links below . .