Soyuz completes its ninth Galileo missionOn May 24, 2016, a Soyuz rocket lifted off from its launch pad in Kourou, French Guiana, carrying the fifth pair of fully operational Galileo satellites, known as FOC-M5. Being the 15th launch of the Russian-built rocket from its South-American launch pad, the mission had a designation VS15.
Ninth Galileo mission (VS15) in May 2016
The VS15 Soyuz launch with FOC-M5 satellites became a "last-minute" add-on mission to the Galileo deployment campaign announced by Arianespace on Feb. 25, 2016, just three months before the scheduled liftoff. According to the company, the European Commission, managing the Galileo Program, has decided to speed up the deployment of the Galileo space segment by adding a Soyuz launch in May 2016, based on the confirmed availability of the satellites built by the OHB prime contractor in Germany. (Previously, these satellites were expected to go into orbit in 2017). The Soyuz flight was to precede an already scheduled launch of four Galileo satellites on an Ariane-5 ES rocket planned for the fourth quarter of 2016, Arianespace said at the time.
The liftoff of the Soyuz-ST-B/Fregat-MT rocket from the ELS pad near Kourou, French Guiana, took place as scheduled on May 24, 2016, at 05:48:43 local time in French Guiana (04:48 a.m. EDT). (It was 08:48 GMT). The 15th Soyuz launch from Guiana (under designation VS15) carried a total payload of 1,599 kilograms, including a pair of Galileo FOC-M5 satellites and a dispenser built by RUAG Space. The same company also supplied the ST fairing covering the payload during the initial phase of the flight.
The pair of satellites delivered during VS15 mission became the ninth and tenth FOC (Full Operational Capability) spacecraft in Europe’s Galileo navigation program. However counting four In-orbit Validation, IOV, satellites, which were also pressed into operational service, they also became the 13th and 14th spacecraft in the operational Galileo constellation. The satellites also received nicknames Danielè and Alizée – after children who won a painting competition organized by the European Commission in 2011.
Following this Soyuz launch, the deployment of the Galileo constellation will shift to the heavier Ariane-5 ES rocket, carrying four satellites at a time. As of December 2015, the first Ariane-5 mission with a Galileo quartet was expected in the second half of 2016. As of May 2016, the first Ariane-5 launch with Galileo satellites was scheduled for Nov. 17, 2016.
Soyuz is still expected to fly one Galileo mission in 2017 and four more launches are considered for 2019 and 2020. The same rocket could also be used to launch 2nd-generation satellites beginning in 2025.
Soyuz VS15 mission with Galileo satellites at a glance:
Initial launch profile of the Soyuz-ST rocket (mission VS15) with Galileo FOC-M5 satellites in May 2016. Credit: Arianespace
Mission profile of the Soyuz-ST rocket (mission VS15) with Galileo FOC-M5 satellites in May 2016. Credit: Arianespace
Altitude profile for a Soyuz VS15 mission with Galileo FOC-M5 satellites.
According to Arianespace, which manages this mission for the European Space Agency, ESA, the powered phase of the first, second and third stages on Soyuz lasted nearly nine minutes. The third stage of the launcher then separated from the upper composite, comprising the Fregat upper stage and the two satellites. The three lower stages and the fairing fell back into the sea.
After a first burn, the upper composite spun up during a ballistic phase lasting about three hours and 15 minutes. Then, Fregat ignited its own engine to bring the upper composite to a transfer orbit over the Earth. At a pre-determined point of this orbit, Fregat ignited for a second burn lasting four minutes to reach the circular orbit of separation. At the end of the mission, the Fregat upper stage was to be emptied of any remnants of its pressurized contents and deactivated.
The entire orbital insertion process was concluded three hours, 47 minutes and 57 seconds after the liftoff with the release of the satellites into a 23,522-kilometer orbit with an inclination 54.946 degrees toward the Equator.
The satellites will later use their own propulsion system to lower their altitude in order to enter their operational orbit in the Orbital Plane A of the Galileo constellation to be ready for operation in around three months.
Preparations for launch
Galileo satellites No. 13 and No. 14 arrived to French Guiana on April 5, 2016. On April 29, the pair was transferred from the S1 facility to S3B facility in Kourou. The satellite No. 14 was fueled on May 3, and satellite No 13 a day later. On May 14, the payload composite including a pair of satellites was attached to its Fregat upper stage.
The Soyuz-ST rocket was rolled out from its integration building to the launch pad on May 20, 2016, and on the same day, the upper composite including the satellites, the Fregat and the payload fairing were also brought to the pad, hoisted to the top of the rocket and integrated with the rest of the launch vehicle.
Installed atop Soyuz’ Fregat upper stage, the two Galileo FOC satellites and their dispenser system are shown partially encapsulated by the two-piece protective payload fairing. Credit: Arianespace
Galileo FOC-M5 launch sequence on May 24, 2016:
Galileo FOC satellites
The current Galileo satellites are built by Bremen-based OHB System as prime contractor, with their navigation payloads provided by Surrey Satellite Technology Ltd. UK, a subsidiary of Airbus Defense and Space.
Known specifications of Galileo FOC-M5 satellites:
Payload section of the Soyuz-ST rocket with Galileo satellites. Credit: Arianespace
Galileo Flight Model no. 10, named Danielè after a Lithuanian student, is fueled for launch. Click to enlarge. Credit: Arianespace
Soyuz is raised to a vertical position over its launch pad on May 20, 2016. Click to enlarge. Credit: Arianespace
A payload section with Galileo satellite is lifted to the top of the Soyuz rocket for final integration on the launch pad on May 20, 2016. Click to enlarge. Credit: Arianespace
A Soyuz moments before liftoff with Galileo FOC-M5 satellites on April 24, 2016. Click to enlarge. Credit: Arianespace