Arianespace Soyuz ST-A successfully launches Pleiades 1B
Arianespace launched their Soyuz ST-A rocket from the European Spaceport “Centre Spatial Guyanais (CSG)” in Kourou, French Guiana on Sunday morning, tasking the veteran launch with lofting the Pleiades 1B satellite into a Sun synchronous orbit. Following its 02:02 GMT lift-off, the satellite was successfully deployed 55 minutes later. This was the second launch attempt, following Saturday morning’s scrub.
Soyuz ST-A Launch:
The veteran Soyuz launch vehicle is a descendent of the R-7 Semyorka, the world’s first intercontinental ballistic missile. The R-7 was designed by Sergei Korolev, and first flew in 1957. A modified version was used to launch the first satellite, Sputnik 1, on 4 October of that year.
The R-7 formed the basis for the Luna, Vostok, Voskhod, Molniya and Soyuz families of rockets, and to date all Soviet and Russian manned spaceflights have been launched using rockets derived from the R-7.
The Soyuz, which first flew in 1966, was a modification of the Voskhod rocket featuring an upgraded and lighter telemetry system, and more fuel efficient engines. It was initially used to launch only Soyuz spacecraft; however with the introduction of the Soyuz-U in 1973 it began to launch other satellites as well.
The Soyuz-U, which remains in service, is the most-flown orbital launch system ever developed, having made around 750 flights to date, plus around 90 more in the Soyuz-U2 configuration optimised to use synthetic propellant.
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, is currently under development and is expected to make its maiden flight next 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 has been optimised to fly from Kourou, and also incorporates a flight termination system and a modified telemetry system.
The vehicle consists of four boosters (first stage), a central core (second stage), a third stage, and the restartable Fregat upper stage (fourth stage). Each vehicle also includes a payload adapter/dispenser and fairing.
The inaugural flight of the upgraded Soyuz 2-1b launch vehicle was successfully performed on December 27, 2006, launching the Corot scientific spacecraft for the French Centre National d’Etudes Spatiales.
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 when the new, enlarged Soyuz ST payload fairing is installed on the vehicle. 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.
This Arianespace flight was designated VS04 in the company’s mission numbering system, denoting the fourth Soyuz liftoff from French Guiana since the medium-lift vehicle’s October 2011 service entry.
It was also the second Soyuz mission launched from the Spaceport in 2012, following Arianespace’s October 12 success that orbited two European Galileo navigation satellites.
The one metric ton Pléiades 1B payload is designed to provide optical observation coverage with 50-centimeter resolution for the French and Spanish defense ministries, civil institutions, and private users.
Operating from a 695-km. quasi-polar heliosynchronous orbit, it will accompany the twin Pléiades 1A spacecraft launched last December on Arianespace’s VS02 Soyuz mission from the Spaceport.
The Astrium division of EADS built both Pléiades satellites for the French CNES space agency, which is prime contractor and system architect. They are based on smaller, cheaper, more agile platforms than their predecessors – the highly-successful Spot satellite series, which was launched on Ariane family launchers by Arianespace beginning in 1986.
Offering exceptional agility to maximize acquisitions over specific areas of interest, the Pléiades satellites can be “rush programmed” to overfly designated target zones, with an automated production system generating 20 km. x 20 km. orthorectified images in 30 minutes.
The system’s capabilities were demonstrated by Pléiades 1A’s imaging of areas along the U.S. eastern seaboard affected by Hurricane Sandy, underscoring the delivery of high-detail data that is essential for emergency response.
(Images via Arianespace).