Arianespace Soyuz ST-B launches Hispasat 36W-1

by Chris Bergin and William Graham

The Arianespace Soyuz ST-B rocket has successfully lofted the Hispasat 36W-1 satellite into orbit on Friday. The launch was the first time a Soyuz rocket had launched a GEO spacecraft from the European Spaceport in Kourou, French Guiana. Liftoff occurred at 01:03 UTC on Saturday morning (Friday evening locally).

Soyuz ST-B Launch:

Hispasat 36W-1 is a telecommunications satellite for Hispasat, and the first to be built using Europe’s new  “SmallGEO” platform.

Hispasat is the Spanish satellite communications operator, a leader in the distribution of content in Spanish and Portuguese. With more than 25 years’ experience, the Hispasat Group maintains an important presence on the Iberian Peninsula and in Latin America, where it is now the fourth-largest satellite operator.

From its orbital position at 36 deg. West, Hispasat 36W-1 will allow Hispasat to provide a wide range of telecommunications services in Spain, Portugal, the Canary Islands and South America.

Hispasat 36W-1 was built by OHB System AG in Bremen, Germany, using a SmallGEO platform.

Developed by OHB System AG under ESA’s ARTES (Advanced Research in Telecommunications Systems) program, the SmallGEO platform line offers satellite operators an entirely European solution in the smaller telecom satellite market.

The SmallGEO family of satellites is defined by a broad spectrum of possible configurations to fulfill a variety of mission objectives. These include telecommunications, Earth observation and laser-communication applications from a geostationary orbit. As propellant options clients can choose between classic, hybrid or electrical.

Depending on the model, the satellite mass at launch can vary between 2,500 kg and 3,500 kg, whereby the individually permitted payload may vary between 300 kg and 650 kg. OHB is currently also working on the SmallGEO projects EDRS-C, Electra and Heinrich Hertz.

The satellite launched on Friday has a commercial relay payload of 20 Ku-band transponders, along with three Ka-band transponders developed by TESAT Spacecom under funding from the DLR German Aerospace Center.

Designated Soyuz Flight VS16 in Arianespace’s numbering system, this mission sported a total payload mass of 3,343 kg.

This mission is the first-ever mission to geostationary transfer orbit performed by Soyuz from the Guiana Space Center in French Guiana.

The more powerful Soyuz-ST configuration is the standard version launched from French Guiana, with the additional performance provided by the Soyuz ST-B variant – including a Fregat-MT upper stage.

The Soyuz-2 was developed from the older Soyuz models, and features digital flight control systems and modernized engines. It first flew in 2004.

Two variants are currently in service; the Soyuz-2-1a, and the Soyuz-2-1b which features an RD-0124 third stage engine which provides additional thrust. The RD-0124 was declared operational on 3 May 2011.

A third configuration, the Soyuz-2-1v, has since debuted. It features an NK-33 engine in place of the RD-108A used on the core stages of the other configurations, and does not include the strapon boosters used by other configurations.

The Soyuz-2 forms the basis for the Soyuz-ST rocket, which is optimized to fly from Kourou, and also incorporates a flight termination system and a modified telemetry system.

With the Soyuz ST-B utilizing the RD-0124 third stage engine, an additional 34 seconds of specific impulse (Isp) significantly increases the vehicle’s overall launch performance.

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The RD-0124 is a staged-combustion engine powered by a multi-stage turbopump, which is spun by gas from combustion of the main propellants in a gas generator. These oxygen-rich combustion gasses are recovered to feed the four main combustion chambers where kerosene – coming from the regenerative cooling circuit – is injected.

Attitude control is provided by main engine activation along one axis in two planes. Liquid oxygen (LOX) and kerosene tanks are pressurized by the heating and evaporation of helium coming from storage vessels located in the LOX tank.

Avionics for the Soyuz launcher are carried in the vehicle’s third stage, and are located in an intermediate bay between the oxidizer and fuel tanks.

As part of the Soyuz’ upgrades for its operations from the Spaceport, the launcher’s flight control system is modernized with a digital control system.

This system incorporates a digital computer and inertial measurement unit that are based on proven technology – giving the Soyuz improved navigation accuracy and control capability.

The new digital control system provides a more flexible and efficient attitude control system, and it gives the additional flight control authority required for the new, enlarged Soyuz ST payload fairing.

In addition, it improves flight accuracy for the Soyuz’ first three stages, and provides the ability to perform in-flight roll maneuvers as well as in-plane yaw steering (dog-leg) maneuvers.

The Fregat upper stage is an autonomous and flexible upper stage designed to operate as an orbital vehicle.  Flight qualified in 2000, it extends the Soyuz launcher’s capability to provide access to a full range of orbits (medium-Earth orbit, Sun-synchronous orbit, geostationary transfer orbit, and Earth escape trajectories).

Fregat consists of six spherical tanks arrayed in a circle (four for propellant, two containing the avionics), with trusses passing through the tanks to provide structural support. The stage is independent from the Soyuz’ lower three stages, having its own guidance, navigation, control, tracking, and telemetry systems.

The Fregat uses storable propellants (UDMH/NTO) and can be restarted up to 20 times in flight – enabling it to carry out complex mission profiles. It can provide 3-axis stabilization or perform a spin-up of the spacecraft payload.

The Fregat first flew in 2000, and has been used on Soyuz-U, Soyuz-FG, Soyuz-2 and Zenit rockets.

The launch was performed from the purpose-built ZLS launch facility for Soyuz – located in the Spaceport’s northern sector near the city of Sinnamary.

Construction of the launch site began in 2007, as Arianespace advanced their plans to add two launch vehicles to their family. (See large set of construction photos in L2).

The Spaceport’s Soyuz launch site combines the proven design elements from the long-existing site at Baikonur Cosmodrome with satellite integration procedures that are in concert with the spacecraft processing used for Ariane missions.

Located 12 kilometers northwest from the existing Ariane 5 launch complex, the new Soyuz facility extends the Spaceport’s operational zone further up the French Guiana coastline.

The launch vehicle’s assembly building is 92 meters long, 41 meters wide, and 22 meters tall, allowing the vehicle to be assembled horizontally, prior to rolling out to the launch site, which is configured after the Russian Baikonur and Plesetsk Cosmodromes, albeit with a new mobile launch service tower.

The Soyuz’ transfer to the Spaceport’s launch zone is performed with the launcher riding horizontally atop a transporter/erector rail car.

Soyuz was then raised into position on the pad, and in contrast with the Baikonur Cosmodrome processing flow, is protected by a gantry that moves into place for payload integration.

(Images via Arianespace and L2.)

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