Galileo Satellites Encapsulated for Launch

August 19, 2014  - By
Image: GPS World


After a one-day postponement, The fifth and sixth Galileo satellites were successfully launched and deployed.


Arianespace has decided to postpone the launch of Soyuz flight VS09 carrying Europe’s fifth and sixth Galileo satellites. This is due to unfavorable weather conditions over the Guiana Space Centre.

Another launch date will be decided depending on the evolution of the weather conditions in Kourou.

Europe’s latest Galileo satellites have been sealed within their launch fairing, atop the Fregat upper stage that will carry them into their final orbit on August 21, ushering in the system deployment phase and paving the way for the start of initial services. Galileo SATs 5-6 are scheduled to lift off at 12:31 GMT from Europe’s Spaceport in French Guiana on top of a Soyuz rocket.

The two Galileo satellites had been attached together on the dispenser that secures them during flight, and then delivers them into orbit. Then August 14 saw the follow-on installation of the stack — the two satellites plus dispenser — onto the Fregat stage. The following day was the last time the two Galileo satellites were seen by human eyes, as the two halves of the protective launch fairing were sealed around the satellites and their upper stage.

Meanwhile, on August 18, the satellites’ three-stage Soyuz launcher was moved by rail onto its launch pad then lifted to the vertical position. The launcher’s mobile gantry was then moved into position around the upright launcher. This allows the next step of the launch campaign to take place, the hoisting up and attachment of the entire upper composite — the launch fairing containing the Galileo satellites, their dispenser and the Fregat fourth stage. At three hours, 47 minutes and 57 seconds after liftoff, the satellites will then be deployed from their Fregat by the dispenser’s pyrotechnic separation system, once their final 23,500 km altitude is reached.

These new satellites will join four Galileo satellites already in orbit, launched in October 2011 and October 2012 respectively. This first quartet were in-orbit validation satellites, serving to demonstrate the Galileo system would function as planned. Now that work has been done, the Full Operational Capability (FOC) satellites being launched on Thursday are significant as the first of the rest of the Galileo constellation.

The payloads generating navigation signals to Earth have been manufactured by Surrey Satellite Technology Ltd in the UK, while the satellites carrying them have been built by OHB in Germany.
A steady stream of launches is planned for the next few years, with two Galileo satellites flown per Soyuz launch and four Galileo satellites flown per launch of an Ariane 5 variant currently in preparation.
The definition, development and in-orbit validation phases of the Galileo program were carried out by ESA and co-funded by ESA and the EU. The Full Operational Capability phase is managed and fully funded by the European Commission. The Commission and ESA have signed a delegation agreement by which ESA acts as design and procurement agent on behalf of the Commission.

The August 21 launch can be watched live here.