Article Posted on : - Aug 18, 2008

FRENCH GUIANA (BNS): Ariane 5 ECA has successfully placed two telecommunications satellites into geostationary transfer orbit, a few minutes after it lifted off from Europe's spaceport at Kourou, French Guiana.

The satellites – AMC-21 and Superbird 7, ejected by the launcher half an hour after the lift off on August 14 – will provide Ku-band television channels and other services over two different regions.

While AMC-21 will cover US, Central America and the Caribbean providing 24 Ku-band channels and enterprise data distribution services, Superbird 7 will enable 28 Ku-band channels and mobile terminal links over Japan, eastern Asia and the Pacific Ocean.

It has been the busiest year for Ariane 5 with seven target missions. The payload in the fifth launch was 8068 kg; with a satellite mass of 7229 kg. Payload adapters and dispensers made for an extra 839 kg.

It was a perfect launch when Ariane 5's cryogenic, liquid fuelled main engine was ignited first leading to the firing of solid fuel rocket boosters resulting in the lift off.

Superbird 7 was first to be ejected from the upper stage of the launcher 25 minutes 42 seconds after main engine ignition. AMC-21 followed at 29 minutes 56 seconds.

Before the ejection, solider boosters were jettisoned 2 minutes 20 seconds after main engine ignition. It was followed up by payload protection fairing getting discarded 3 minutes 12 seconds later during the climb through the Earth's atmosphere.

The main engine was shut down at 8 minutes 54 second and after 5 more seconds the main cryogenic stage separated from the upper stage and its payload. Another 4 seconds later cryogenic upper stage was ignited to carry forward the journey. At an altitude of 547 kilometers when the vehicle was traveling at 9438 meters (34000 kmh) per second, the upper stage engine was shut down, 24 minutes 44 seconds into the flight, after achieving conditions for geostationary transfer orbit injection.

Superbird-7 was commissioned by Japanese Space Communications Corporation in contract with Mitsubishi Electric Corporation. AMC-21 is for American operator SES AMERICON, a company of the SES group, world's leading satellite operator.

Ariane 5 ECA, the latest variant of Ariane 5 launcher, can place payloads upto 9.6 tonnes into geostationary transfer orbit. It is capable of handling two big sized satellites. Its track record is proven by the fact that the latest was its 41s launch. Out of these, 27 have been success in a row. The Thursday's mission was 9th in last 12 month making it a workhorse.

This is the reason why big companies are using it as a preferred choice to place satellites in the orbit. Superbird-7 was the 7th space communication satellite launched by Ariane while 23 of Japanese commercial satellites have been carried by the vehicle.