The third and fourth Galileo Full Operational Capability (FOC) satellites are a confirmed “fit” for their Arianespace Soyuz launch in March, having made initial contact with the mission’s dual-payload dispenser in French Guiana.

This week’s activity – which is called the fit check – was completed over a two-day period inside the Spaceport’s S1A payload preparation building. The two satellites were installed separately, with the Flight Model #3 (FM3) spacecraft integrated on – and subsequently removed from – the dispenser on Monday. Flight Model #4 (FM4) underwent the same process the following day.

The payload dispenser for Galileo was developed by RUAG Space Sweden for Arianespace, and carries one satellite on each side. It will deploy the spacecraft during their Soyuz launch by firing a pyrotechnic separation system to release them in opposite directions at the orbital insertion point.

Final integration on the dispenser is to be performed during upcoming processing at the Spaceport, and will be followed by the completed unit’s installation on Soyuz.

This March 27 mission – designated Flight VS11 in Arianespace’s numbering system – will be the company’s fourth launch carrying spacecraft for the Galileo constellation, which is Europe’s initiative for a satellite-based navigation system. FM3 and FM4 were built by OHB System, with Surrey Satellite Technology Ltd. supplying their navigation payloads.

The Galileo network’s complete operational and ground infrastructure will be deployed during the Full Operational Capability phase, which is managed and funded by the European Commission. The European Space Agency has been delegated as the design and procurement agent on the Commission’s behalf.