Arianespace is gearing up this week for its upcoming Soyuz Flight VS12 - scheduled for September 10 from French Guiana - with initial fit-check activities completed for the mission's two passengers: the latest European Galileo navigation satellites.

During activity inside the Spaceport's S1A clean room facility, the correct fit was confirmed for the Galileo spacecraft on their specially-designed payload dispenser, which will hold the satellites in a side-by-side configuration atop Soyuz' Fregat upper stage during the mission and deploy them at the orbital insertion point.

As part of this process, the spacecraft - which are the fifth and sixth in Galileo's full operational capability (FOC) phase - are installed separately, then removed from, the RUAG Space Sweden-built dispenser that uses a pyrotechnic separation system to release them in opposite directions during the flight.

Completion of the fit-check allows the next stage of payload preparations to begin, including fueling, final integration with the payload dispenser, and the completed unit's subsequent installation on Arianespace's medium-lift workhorse Soyuz vehicle.

Galileo's FOC phase is managed and funded by the European Commission, with the European Space Agency delegated as the design and procurement agent on the Commission's behalf. The latest Galileo FOC spacecraft were produced by OHB System, with Surrey Satellite Technology Ltd. supplying their navigation payloads that will generate precise positioning measurements and services around the world.

At full deployment, the Galileo program will consist of 30 satellites - comprising operational spacecraft and reserves - situated on three circular medium Earth orbits at some 23,200 km. altitude inclined 56 deg. to the equator. The constellation - and associated ground infrastructure - will provide high-quality positioning, navigation and timing services under civilian control, and be interoperable with the U.S. GPS and Russian Glonass global positioning systems.

This week's processing with the Galileo satellites is part of Arianespace's busy operational pace in French Guiana, where payload and launcher activity has commenced for four upcoming missions: Ariane 5 Flight VA225, Soyuz Flight VS12, Ariane 5 Flight VA226 and Vega Flight VV06.

Arianespace's Flight VS12 is planned to be the company's eighth launch this year, following August 20's scheduled Ariane 5 Flight VA225, as well as six successful missions already completed in 2015 - comprising separate flights of three Ariane 5s, two Vega vehicles, and a Soyuz launcher.