Arabsat 5C is a communication satellite that was built by Astrium and Thales Alenia Space. It will be operated by Arabsat. At a mass of 4,630kg and a 30.75-meter span in orbit, Arabsat will provide 26 active channels in C-Band and 10 wide band transponders in Ka-Band. The satellite's dimensions are 2.1 x 2.35 x 4.09 meters. The satellite is based on the flight proven Eurostar E3000 platform. It will be placed in geosynchronous orbit and operate at a position of 20° East and cover the Middle East and Africa. The design life of Arabsat 5C is estimated at 15 years. 12 Kilowatts of power will be provided by the satellite’s solar arrays at the end of its life. Arabsat is 3-axis stabilized. Arabsat 5C will provide TV Broadcast Services as well as communication services.
Arabsat and Arianespace have been cooperating since 1985 when Arianespace launched Arabsat 1A. 5C is the 8th satellite to be launched by the European launch vehicle.
The second payload for this flight will be the SES-2 Telecommunications Satellite which was built by Orbital Sciences Cooperation for the operator SES. Weighing 3,200kg at liftoff, SES-2 is a three-axis stabilized satellite based on a STAR 2.4 platform. The satellite is 4.9 x 3.3 x 2.3 meters in dimensions and it will have a 23.6-meter span once in orbit. It has 24 Ku-Band Transponders and 24 C-Band Transponders mounted on it. Electricity is provided by solar arrays. 6 kilowatts of power consumtion are planned for the end of the satellite’s mission. When the satellite is in its targeted orbit of 82° East, it will provide coverage for the Caribbean Islands and North America. SES-2 has a design life of 15 years. SES-2 will provide TV Services and VSAT services for professional customers and government agencies. This satellite will also carry an Infrared Payload called CHIRP.
SES and Arianespace have a developed a close relationship since the first satellite for SES was launched aboard an Ariane. SES-2 is the 35th SES satellite to be orbited by the European launcher.
Mission Preview and Timeline
|Time||Event||Altitude (Km)||Velocity (m/s)|
|0:00:00.00||Vulcain Engine Ignition Sequence||0||0|
|0:00:07.05||Solid Rocket Booster Ignition||0||0|
|0:02:21.00||SRB Burnout and Jettison||69.000||1995.0|
|0:03:08.00||Payload Fairing Jettison||106.900||2190.0|
|0:08:59.00||Core Stage shutdown||186.700||6890.0|
|0:09:09.00||2nd Stage Ignition||186.600||6919.0|
|0:27:21.00||Arabsat 5C Release||973.400||9087.0|
|0:47:58.00||Ariane 5 - End of Mission||5.845.000||6309.0|
The Countdown for a Launch of the Ariane 5 Rocket begins 11 hours and 30 minutes before the launch window opens. At L-7:30 final electrical checks will be made before Fueling starts just under 5 hours to liftoff. 90 Minutes into LOX and LH2 Tanking, the Vulcain Main Engine is being chilled down by the supercold propellants. 1 hour and 10 minutes prior to launch, final checks of all communication connections and telementry links are conducted to ensure all Ground Tracking Stations are ready to support the mission. The Vehicle will be placed in a stable configuration for T-7 Minutes and Holding. The Launcher can remain in this configuration throughout the launch window. At T-7 Minutes and Counting, the Synchronized Sequence begins. Computers are watching all parameters of the vehicle and ground support equipment as final reconfigurations are made to put the Ariane in a launch configuration. Should any system show an off-nominal performance, the Computers will automatically recycle all systems to their T-7-Configuration to back out of the automated sequence. 4 Minutes prior to launch, all tanks of the first and second stage are being pressurized for flight. 1 Minute before T-0, the vehicle switches to onboard power. 30 Seconds before Ignition, Water begins flowing into the Flame Trenches. Hydrogen aspiration of the Vulcain engine starts 18 seconds before it is ignited. The Cryogenic arms that are used for critical connections including fuel lines are retracted. 4 seconds before the Ignition Sequence commences, the Handoff to Ariane’s onboard computers occurs and the Guidance System enters its flight mode one second later.
At T-0, the Vulcain Engine Ignition Sequence begins. Three pyrotechnic devices are used to ignite the main engine which reaches flight thrust at T+4.5 seconds. Engine performance is being monitored before the Solid Rocket Boosters are ignited at T+7.05 seconds. Liftoff occurs just a quarter of a second later. The two Solid Rocket Boosters provide 92% of total thrust at blastoff. The launcher climbs vertically for 6 seconds before the pitch maneuver begins which puts the rocket into the proper trajectory that is required to reach the targeted Main Engine Cutoff point. After 2 minutes and 21 seconds of powered flight, the SRBs burn out and are jettisoned to fall back to Earth and into the Atlantic Ocean. Immediately after SRB jettison, the onboard computers calculate the precise trajectory that is required to recover from minimal transients that are nominal for the SRB Phase. That course correction is conducted in real time by swivalling the main engine. The next Event is Payload Fairing Jettison. The Fairing is used to protect the Payloads from thermal loads during atmospheric flight. When heat levels are at an acceptable level, the fairing is jettisoned by pyrotechnically initiated separation tubes. Separating the fairing as early as possible increases ascent performance. At 9 minutes into the flight, the Vulcain Egnine shuts down for first stage cutoff. Stages #1 and #2 separate from each other and the second stage with its HM-7B engine continue powered flight after the engine ignites. The first stage falls back to Earth and impacts off the coast of Africa in the Gulf of Guinea. The second stage will burn for more than 15 minutes before final engine cutoff. Afterwards, the stage re-orients itself to the proper attitude to release the first payload. When the first Spacecraft Separation is successful, the coast phase continues with more orientation maneuvers and the separation of the Slyda 5. This is a fairing like object that is used to install two payloads on top of the rocket. The first payload is mounted atop the Sylda and the second satellite is hidden beneath it until the first payload is released. With Sylda Separation, the path is clear to jettison the second and final payload into its targeted orbit. The second stage continues its mission for another 13 minutes during which it performs reorientation maneuvers and avoidance firings. At T+47 minutes and 58 seconds, Ariane’s mission is complete. The two satellites will then be in a geostationary transfer orbit that will be optimized when the spacecraft fire their individual engines to reach a precise position.