Getting ready for the launch next week is ...
Arianespace’s Ariane 5 which is now complete and ready for its mission next week from the Spaceport in French Guiana. The craft will orbit four more spacecraft to join the European Galileo constellation of navigation satellites.
Ariane 5’s afternoon liftoff on December 12 will be the year-ending mission in 2017 for Arianespace – completing a busy 12 months that already have involved 10 flights from the Spaceport: five performed with the heavy-lift workhorse, three utilizing the lightweight Vega and two with the medium-lift Soyuz.
Designated Flight VA240 in Arianespace’s numbering system, next Tuesday’s mission will mark the second time an Ariane 5 ES version will be employed to orbit satellites for Europe’s Galileo satellite navigation system. The Ariane 5 ES configuration has a storable propellant upper stage that replaces the cryogenic upper stage on Ariane 5 ECA launchers typically operated by Arianespace on missions to geostationary transfer orbit (GTO) with telecommunication satellite passengers.
During activity in the Spaceport’s Final Assembly Building, the Ariane 5’s build-up process was completed with the lowering of its ogive-shaped payload fairing over the four satellite passengers – which previously were positioned atop the launcher’s core section.
Following final check-out, Ariane 5 will be ready for its rollout to the ELA-3 launch zone on Monday, December 11, positioning this vehicle for a liftoff the next day at exactly 3:36:07 p.m., local time in French Guiana.
The four Galileo satellites, which are clustered around a multi-passenger dispenser system, will be deployed in two phases during the mission to medium Earth orbit (MEO) lasting 3 hours, 55 minutes.
For Flight VA240, the storable propellant upper stage is to be ignited twice, bringing it to an altitude of 22,925 kilometers for deployment of the Galileo spacecraft – with 20 minutes between the release of these Full Operational Capability (FOC) satellites in two pairs.
At the completion of next week’s mission, Arianespace’s will have launched 22 Galileo spacecraft utilizing Ariane 5 and its Soyuz launchers (which orbited two of the navigation payloads per mission). Of this total, 18 are operational satellites, along with four initial In-Orbit Validation (IOV) spacecraft lofted in 2011 and 2012.
As Europe’s own global navigation satellite system operated under civilian control, Galileo is designed to provide guaranteed high-precision positioning around the world. Initial services began in December 2016. The complete Galileo constellation will comprise a total of 24 operational satellites (along with spares).
The Galileo program is funded and owned by the European Union. The European Commission has overall responsibility for the program – with Flight VA240 to be performed by Arianespace on behalf of the European Commission under contract with ESA.
ESA transferred formal responsibility for the oversight of Galileo in-orbit operations to the GSA (European GNSS Agency) in July 2017. Therefore, GSA will be in charge of operating the Galileo satellite navigation systems on behalf of the European Union as of Flight VA240 – and taking responsibility for operating the latest four satellites once they are separated from Ariane 5. Satellite positioning operations and system operation will be carried out in conjunction with ESA.
The Galileo satellites are produced by prime contractor OHB System in Bremen, Germany, with the payloads supplied by U.K.-based Surrey Satellite Technology Ltd (SSTL), which is 99 percent owned by Airbus Defence and Space.