Arianespace Soyuz ST-B in troubling Galileo launch
An Arianespace Soyuz ST-B launched two Galileo satellites from the European Spaceport in Kourou, French Guiana on Friday. However, the lofting of the two FOC-M1 (FM01 and FM02) satellites – which took place at 12:27 UTC – did not result in a correct orbital injection. Controllers are now looking into their options to save the satellites.
This launch marked the business end of Europe’s Global Navigation Satellite System (GNSS) constellation build up.
Following the launch of four satellites Galileo In-Orbit Validation (IOV) satellites, forming the operational nucleus of the full 30-satellite constellation – FM01 and FM02 will be the first two “Full Operational Capability (FOC) birds to head into orbit.
Named “Doresa” and “Milena”, the satellites were built in Bremen, Germany by FOC prime contractor OHB System, and are named for children who were among those winning a European Commission-organized painting competition in 2011.
The 700 kgs birds sport two Passive Hydrogen Maser atomic clocks; two Rubidium atomic clocks; Clock monitoring and control unit; Navigation signal generator unit; L-band antenna for navigation signal transmission, C-band antenna for uplink signal detection, two S-band antennas for telemetry and tele-commands and a search and rescue antenna.
Galileo’s highly-accurate atomic clocks will provide the accuracy of the system. Each satellite emits a signal containing the time it was transmitted and the satellite’s orbital position.
The Galileo program is Europe’s initiative for satellite navigation, providing a highly accurate global positioning system under civilian control – consisting of 30 satellites, along with European control centers and a worldwide network of sensor and uplink stations.
The complete Galileo constellation is to be composed of 27 operational satellites and three reserves, distributed along three circular medium Earth orbit planes at an altitude of 23,222 km., inclined 56 deg. to the equator
Arianespace was chosen to deploy the entire Galileo constellation of 30 satellites. This began with the launch of the first two experimental satellites, Giove-A and Giove-B, orbited by Arianespace’s Starsem affiliate on Soyuz launchers from Baikonur Cosmodrome in 2005 and 2008.
The remaining 24 Galileo constellation satellites will be orbited over the next year or so, using six additional Soyuz vehicles carrying two spacecraft each, along with three Ariane 5 ES rockets configured with four per launch.
However, despite the Arianespace webcast noting no issue with the launch, it was later admitted the satellites were lofted into the wrong orbit.
“Following the announcement made by Arianespace on the anomalies of the orbit injection of the Galileo satellites, the teams of industries and agencies involved in the early operations of the satellites are investigating the potential implications on the mission,” noted a short statement, many hours after the event.
It is unlikely the satellites can be eased into their correct orbit, even with a large extension to their transit time. However, ESA are not classing the satellites as lost at this time.
“Both satellites have been acquired and are safely controlled and operated from ESOC, ESA’s Operations Centre in Darmstadt, Germany,” the Agency added.
“Further information on the status of the satellites will be made available after the preliminary analysis of the situation.”
Designated Soyuz Flight VS09 in Arianespace’s numbering system, this mission – the medium-lift vehicle’s ninth liftoff from French Guiana – joined the company’s record 2014 launch manifest.
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 modernised 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, debuted at the end of last year. 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 optimised 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 gases 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 assembles 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, O3b and L2.)