Arianespace ready for final Ariane-5 flight of 2014 with DIRECTV-14 and GSAT-16
The sixth launch of an Ariane-5 rocket is scheduled to take off on Dec. 4 between 8:38 p.m. and 9:48 p.m. from the Kourou spaceport in French Guiana. Flight VA221 will see the Ariane-5 flying in the ECA configuration with two satellite passengers: DIRECTV-14 and GSAT-16.
The DIRECTV-14 satellite is the sixth satellite built by SSL (Space Systems/Loral) for operator DIRECTV. The high-capacity spacecraft is based on the SSL 1300 platform, DIRECTV-14 is a 20-kilowatt class Ka-band and reverse-band digital broadcast satellite that will be used to deliver Ultra HD and other new consumer services for DIRECTV.
DIRECTV-14 delivers hundreds of channels of crystal-clear digital programming to more than 31 million customers in the U.S. and Latin America with small-diameter dish antennas. This satellite will provide service for users across the U.S. (including Hawaii and Alaska) and Puerto Rico. The satellite will have a liftoff mass of approximately 6,300 kg. DIRECTV-14 is expected to operate for 15 years.
DIRECTV-14 will be joined on the flight by the Indian Space Research Organization’s (ISRO) GSAT-16 telecommunications satellite. Designed, assembled and integrated by ISRO, GSAT-16 is to deliver C- and Ku-band telecommunications services that include very small aperture terminal (VSAT) transmissions, TV broadcasting and emergency communications. GSAT-16 will weigh approximately 3,180 kg at liftoff.
After its injection into GTO, ISRO‘s Master Control Facility (MCF) at Hassan takes control of the satellite and performs the initial orbit raising maneuvers using the satellite’s on-board Liquid Apogee Motor (LAM), finally placing it in the vicinity of circular Geostationary Orbit. After this, the deployment of appendages such as the solar panels, antennas and three axis stabilization of the satellite will be performed. GSAT-16 will be positioned at 55 degrees East longitude in the geostationary orbit and co-located with GSAT-8. The operational lifetime of GSAT-16 is expected to be 12 years.
Both satellites arrived in October at the launch site. Build-up of the Ariane-5 rocket started also in early October with the Cryogenic core stage being lifted into position onto the mobile launch table and integration of the twin solid propellant boosters.
A few days later the cryogenic upper stage and the Ariane-5 equipment bay was installed atop the vehicle’s core stage. On November 14 the Ariane-5 rocket was rolled out to the Spaceport’s Final Assembly Building (BAF) in French Guiana. There the launcher was made ready for integration of its satellite payloads.
That activity was followed by the final verifications of the Ariane-5 rocket.Thursdays launch will be the 77th launch of an Ariane-5 rocket and will really start with a synchronized sequence 7 minutes before T-0. The synchronized sequence is primarily designed to perform the final operations on the rocket prior to launch, along with ultimate checks needed following switchover to flight configuration. This sequence is fully automatic, and is performed by the onboard computer and by two redundant computers at the ELA 3 launch complex until T-4 seconds.
The computers command the final electrical operations (switching from ground power supply to onboard batteries). They also place the propellant and fluid systems in flight configuration and perform associated checks. At T-4 seconds, the onboard computer takes over control of final engine startup and liftoff operations. It starts the ignition sequence for the Vulcain main engine at T-0 and engine operation from T+4.5 to T+7.3 seconds. Ignition of the solid boosters for lift-off follows at T+7.3 seconds.
As soon as the rocket is clear of the launch table it climbs vertically for 6 seconds then it rotates towards the East maintaining an attitude that ensures the axis of the launcher remains parallel to its velocity vector, in order to minimize aerodynamic loads throughout the entire atmospheric phase, until the solid boosters are jettisoned. The payload fairing protecting the DIRECTV-14 and GSAT-16 spacecraft is jettisoned shortly after the boosters are jettisoned about 200 seconds after lift-off.
Once this first part of the flight is completed, the onboard computers optimize the trajectory minimizing propellant consumption to bring the launcher to its targeted orbit at the end of the main stage propulsion phase, and then the final orbit at the end of the flight of the cryogenic upper stage. The main stage falls back off the coast of Africa in the Atlantic Ocean.
On orbital injection, the launcher will have a velocity of approximately 9,320 meters per second, and will be at an altitude of about 694.9 kilometers. Separation of the DIRECTV-14 satellite will come at 27 minutes after launch followed 5 minutes later by GSAT-16 separation.
European company Arianespace was founded in 1980 as the world’s first launch Service & Solutions company. Arianespace has signed more than 390 launch contracts and launched 490 satellites. More than two-thirds of the commercial satellites now in service worldwide were
launched by Arianespace and it now has a backlog of more than 40 satellites to be launched.
A native of the Netherlands, van Oene became ‘infected’ with the ‘space virus’ by an enthusiastic school teacher in 1981. Since 1994 he has been a freelance space photographer and writer for magazines and websites in Holland, Belgium and ‘Spaceflight’, the magazine of the British Interplanetary Society. van Oene is also the co-founder and CFO of SPACEPATCHES.NL. This Netherlands-based foundation currently produces all the official Soyuz crew patches for the Russian Space Agency, Roscosmos.