January 28, 2020

Assembly and launch facilities

Soyuz is operated from the Guiana Space Centre, Europe’s spaceport. Like Ariane and Vega, launcher elements are shipped to Kourou in containers aboard the MN Toucan and MN Colibri. The only difference is their departure point, from Saint Petersburg in Russia. A Soyuz launch campaign lasts one to two months. Each phase is described below.

Launcher assembly

On arrival in Kourou at the port of Pariacabo in ten containers, the Soyuz launcher and Fregat upper stage are trucked to the ELS launch complex at the Guiana Space Centre (CSG). 

In the foreground, the MIK building where the lower stages of Soyuz are assembled. In the background, the launch pad and its huge mobile gantry. Credits: CNES/ESA/Arianespace/CSG video and photo department/R Liétar, 2011.

The launcher is assembled horizontally in the MIK integration building. The four tapered side boosters making up the first stage are attached one after the other to the central core of the second stage (see video). Then the third stage is integrated. All of these operations are performed by Russian teams and take about a fortnight.

The side boosters are mated to the central core.

Preparation of Fregat

The Fregat spacecraft is removed from storage, prepared and checked in the MIK building. Up to 2015, it was then transferred for fuelling to the EPCU payload preparation facility (S3B) located at the ELA2 launch complex, roughly 12 kilometres from the MIK. Since 2015, fuelling operations—which take more than a week—are conducted in a new building at the ELS called FCube (for Fregat Fuelling Facility).

The Fregat stage is prepared in the MIK building.

ELS Soyuz launch complex at the CSG

The ELS Soyuz launch complex was built specifically for the Russian launcher on a new site in the municipality of Sinnamary, 12 kilometres north-west of the ELA Ariane launch complex. It is based on the same architecture as the launch complexes in Baikonur and Plessetsk, with a launch centre (CDLS, virtual tour) and an assembly building (MIK, virtual tour) connected to the launch pad (ZLS, virtual tour) by railway. Excavation and earthworks began in 2004 and work on the buildings and launch pad was conducted between 2007 and 2011 with CNES as prime contractor. Construction called on more than 700 people of different nationalities, 250 of them Russian.


Soyuz is capable of carrying a single satellite or a multi-satellite payload. Like for Ariane and Vega, payloads are prepared in the EPCU payload preparation facility, in zone S1 or S5 (virtual tour of S5). Satellites are fuelled in S5 and then transferred to zone S3B for mating with the awaiting fuelled Fregat stage. They are then encapsulated under the fairing. 

The 9th and 10th Galileo satellites are mated atop the Fregat stage.

Together, the Fregat stage, satellite(s) and fairing form the Upper Composite, standing 12 metres tall, spanning 4.1 metres and weighing 9 to 16 tonnes. Four days before launch, the composite is trucked on a dedicated platform from zone S3B to the launch pad where it is hoisted onto the Soyuz launcher, now in its erect position.

All operations to prepare, encapsulate and mate satellites atop the launcher stack are performed by Arianespace.

Encapsulation of the Fregat stage and satellites.


Four days prior to launch, Soyuz is placed on a transporter/erector rail car and towed by a special tractor to the launch pad (ZLS) 600 metres from the MIK building. Once on the concrete launch table overlooking the flame pit, the transporter/erector raises the three-stage composite into position (video). The launcher support system known as the ‘tulip’ (from the Russian word tyoulpan) holds the upright launcher around its ‘waist’.

A giant 52-metre-high mobile gantry weighing 740 tonnes (called MBO2) is moved into position around Soyuz to:

  • protect it from the weather
  • enable technicians to work on it
  • mate it with the upper composite

The Soyuz three-stage composite is towed on its rail car from the MIK to the launch pad.

This rail-mounted mobile gantry is specific to the French Guiana facilities and has been replicated by the Russians for the Soyuz launch pad at their Vostochny Cosmodrome. The gantry replaces the narrow, open gangways normally used in the Soyuz processing flow, which do not meet the requirements of European regulations. It also enables the same satellite integration standard to be used for all launchers—Ariane, Vega and Soyuz—lifting off from the CSG. In Baikonur, the upper composite is integrated horizontally on the three-stage composite in the MIK building, and not vertically as at the CSG.

On D–3 the upper composite is trucked to the pad and hoisted atop the launcher by the mobile gantry’s crane.

On D–2 a launch countdown rehearsal is performed for the three-stage composite, checking of the Fregat stage and radioelectric tests.

On D–1 a countdown rehearsal is performed for the Fregat and satellites.

Concurrently with these operations a Launch Readiness Review (LRR) chaired by Arianespace is held with all of the Russian and European operations teams, Russian certifying bodies, the launch base and the satellite customer. The LRR gives the ‘go/no-go’ to enter the final countdown.

The lower composite of Soyuz is raised into position by the blue transporter/erector. The four yellow and blue structures are the counterweighted metal support arms of the ‘tulip’ that open out and away from the launcher as it lifts off the pad.

At T–9 hrs, the countdown begins.

At T–5 hrs, the ‘go’ is given to fuel the three-stage composite.

At T–1 hr. 35 min, the three launcher stages are fuelled. This operation takes 1 hr. 15 min.

At T–1 hr. 10 min, the mobile gantry is rolled back 60 metres from the launch pad to leave Soyuz clear for launch.

At T–19 s, the command to launch is given.

At T–16 s, the first-stage and second-stage engines are fired.

Launcher and pad operations are controlled from the Soyuz Launch Centre (CDLS).

Soyuz on the pad for flight VS19 on 6 November 2018. The smoke is from outgassing of liquid oxygen.


Launcher operations at the ELS with the launch base’s telemetry and tracking stations, range safety and emergency response systems are coordinated from the Jupiter 2 control room as for Ariane and Vega launches.

All the requirements set out in the French Space Operations Act (FSOA) apply to the Soyuz launcher. CNES is tasked with enforcing them to ensure that populations, property, the environment and public health are protected at each launch.

To meet the FSOA requirements that apply to any vehicle operating from the CSG, Soyuz has been adapted with:

  • transmitters, receivers and antennas compatible with the frequencies and network of stations used at the CSG, which means that the same reception/communication systems as for Ariane and at downrange tracking stations can be used;
  • modifications to flight software on the three-stage composite and Fregat stage;
  • a European ‘range safety kit’ (KSE) to allow radars to track the launcher’s trajectory and controllers to abort the flight from the ground in the event of an anomaly likely to endanger populations; this manual abort system complements the Russian flight system that automatically shuts down the engines in the event of a failure.
  • pyrotechnic valves on the tanks to let in water and sink them so that stages splashing down at sea do not pose a hazard floating on the surface.

20th launch of a Soyuz from the CSG on 19 December 2018, carrying the French CSO-1 military satellite.