Galileo deals 4 of a kind

An Ariane 5 heavy-lift rocket launched four full operational capability (FOC) Galileo satellites on Nov. 17, accelerating deployment of the new satellite navigation system.

The rocket carried Galileo satellites 15–18 from Europe’s Spaceport in Kourou, French Guiana, into space, releasing the first pair 3 hours, 25 minutes after liftoff, while the second separated 20 minutes later.

All four are at their target altitude, after a smooth release from the new dispenser designed to handle four satellites.

Galileo satellites 15–18 being deployed from their dispenser, two at a time. (Artist’s rendering: ESA)

Over the next few days, engineers will nudge the satellites into their final working orbits and begin tests to ensure they are ready to join the constellation. This is expected to take six months or so.

This mission brings the Galileo system to 18 satellites.

The satellites already in orbit will allow the European Commission to declare the start of initial services, expected by year’s end.

The previous 14 satellites were launched two at a time using the Soyuz–Fregat rocket.

Galileo FOC-M6 satellites. The 15th to 18th satellites were built by prime contractor OHB System in Bremen, Germany, with the payloads supplied by UK-based Surrey Satellite Technology Ltd., owned by Airbus Defence and Space.

The satellites weighed 714, 715, 714 and 715 kg. at launch, respectively, and were placed in a circular medium Earth orbit (MEO) in Plane C, at an altitude of 22,922 km. and an inclination of 54.57 degrees. They will subsequently be moved to their operational orbit at an altitude of 23,222 km.

The Kourou launch team.

“Now that we can rely on the powerful Ariane 5, we can anticipate the quicker completion of Galileo deployment, permitting the system to enter full operation,” said Paul Verhoef, ESA’s director for the Galileo Programme and Navigation-related Activities.

Two additional Ariane 5 launches are scheduled in 2017 and 2018. The full system of 24 satellites plus spares is expected to be in place by 2020.

“With this 75th successful launch in a row, Ariane 5 sets a new record within European developed launchers and proves once more its reliability,” said Daniel Neuenschwander, ESA’s director for Launchers.