Dual Launch Of Telecommunications Satellites On Ariane 5
Early on the morning of August 22, an Ariane 5 ECA launcher lifted off from Europe’s Spaceport in French Guiana on its mission to place two telecommunications satellites, JCSat-12 and Optus D3, into geostationary transfer orbits.
Lift-off of flight V190 took place at 00:09 CEST/Paris (22:09 UTC/GMT [21 August]; 19:09 UTC-3/French Guiana [21 August]). The target injection orbit had a perigee altitude of 250 km, an apogee altitude at injection of 35 786 km and an inclination of two degrees. The satellites were accurately injected into their transfer orbits about 27 and 34 minutes after lift-off.
JCSat-12 will operate in the Ku- and C-bands, providing broadcast and broadband services covering Japan, the Oceania and Asia-Pacific regions and Hawaii. Optus D3 will operate in the Ku-band, delivering direct-to-home TV broadcast, Internet, telephony and data transmission services for Australia and New Zealand. The payload mass for this launch was 7622 kg; the satellite masses totaled 6523 kg, with payload adapters and dispensers making up the additional 1099 kg.
Arianespace and Europe’s Spaceport are planning seven Ariane launches during 2009, maintaining the heavy-lift vehicle’s flight rate. The ability to sustain high launch rates has already been demonstrated ““ during the 12-month period from August 2007 to August 2008, there were nine launches (V177 to V185, inclusive).
The Ariane 5′s cryogenic, liquid fuelled main engine was ignited first. Seven seconds later, the solid fuel rocket boosters were also fired, and a fraction of a second after that, the launch vehicle lifted off.
The solid boosters were jettisoned 2 min: 20 sec after main engine ignition, and the fairing protecting the payload during the climb through Earth’s atmosphere was discarded at 3 min: 28 sec. The launcher’s main engine was shut down at 8 min: 52 sec; nine seconds later the main cryogenic stage separated from the upper stage and its payload.
Four seconds after main stage separation, the engine of the launcher’s cryogenic upper stage was ignited to continue the journey. The upper stage engine was shut down at 24 min: 35 sec into the flight, at which point the launch vehicle was traveling at 9458 meters per second (just over 34 000 km/h) at an altitude of 525 kilometers and the conditions for geostationary transfer orbit injection had been achieved.
At 26 min: 44 sec after main engine ignition, JCSat-12 separated from the launcher’s upper stage, followed by Optus D3 at 34 min 10 sec. The launch vehicle’s flight operations were completed at 44 min: 21 sec after main engine ignition.
Ariane 5 ECA
Ariane 5 ECA is the latest version of the Ariane 5 launcher. It is designed to place payloads weighing up to 9.6 tons into geostationary transfer orbit. With its increased capacity, Ariane 5 ECA can handle dual launches of very large satellites.
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