Arianespace’s VS11 mission carrying FOC satellites 3 and 4. Photo: Arianespace.

[Via Satellite 03-30-2015] On March 27 Arianespace completed the launch of the third and fourth Full Operational Capability (FOC) satellites for Europe’s Global Navigation Satellite System (GNSS) Galileo. The 700-kg satellites, known as Adam and Anastasia, reached their intended deployment point following two burns of the Fregat upper stage, separated by a three-hour-plus ballistic phase.

The previous Galileo launch left FOC satellites Doresa and Milena in an elliptical orbit due to an anomaly with the Fregat upper stage. Though originally jeopardized by the underperformed Soyuz launch, both have been maneuvered to the correct Medium Earth Orbits (MEO). Arianespace traced the cause of the anomaly to frozen hydrazine, and implemented corrective measures with Fregat manufacturer NPO Lavochkin to prevent any reoccurrence.

OHB System is the prime contractor for the Galileo FOC satellites, with Surrey Satellite Technology Ltd. (SSTL) supplying their navigation payloads. Arianespace is contracted to launch six more Galileo missions: three using the Soyuz rocket for six satellites, and three with the Ariane 5 for 12 satellites.