INSATs: Silver Jubilee(1982-2007)

INSATs: Silver Jubilee(1982-2007)*

India's latest telecommunication satellite INSAT-4B was today successfully launched by the European Ariane 5 rocket from the spaceport of Kourou in French Guiana.

INSAT-4B, that would give a big boost to Direct-to-Home (DTH) TV services and augment the INSAT system, was injected into space within minutes after it's co-passenger Skynet 5A military communication satellite for the British Ministry of Defence was placed in orbit.

Within minutes after the launch, Indian Space Research Organisation (ISRO)'s Master Control Facility at Hassan in Karnataka took control of INSAT-4B.

As the second satellite in the Insat-4 series, the 3,025 kg Insat-4B is carrying 12 high power Ku-band (11-14 GHz) transponders and 12 C-band (4-6 GHz) transponders to augment the capacity for DTH television services and expanding the Insat capacity for other communication and broadcasting services.

About 30 minutes after the launch, the Indian satellite was placed in an elliptical geo-synchronous transfer orbit (GTO), with a perigee (nearest point to earth) of 250 km and an apogee (farthest point to earth) of 35,786 km.

The spacecraft will be manoeuvred into the 36,000 km high circular geo-synchronous orbit (GSO) by firing its liquid apogee motor (LAM) in phases.

In GSO, Insat-4B will be co-located with Insat-3A satellite at 93.5 degree east longitude," the official said.

"The over three-tonne satellite has been built at the ISRO satellite centre in Bangalore at a cost of Rs 2.15 billion. The launch cost is estimated to be Rs.2.25 billion. The satellite has also been insured for Rs.600 million," the official disclosed.

The solar panels of the 50-ft satellite can generate about 5,800 watt. Three lithium ion batteries of 100 ampere-hour (Ah) capacity will generate power to maintain the satellite's key functions during eclipse periods.

The 24-year Indian National Satellite (Insat) system has revolutionised the communications system spanning telecom, meteorology, radio and television broadcasting and other vital services such as education, health, agriculture and business.

"The Insat system has become the largest domestic communication satellite system in the Asia-Pacific region, with nine spacecraft, including Kalpana-1, Gsat-2, Edusat and Insat-4A in service, with 175 transponders in C, extended C and Ku bands," the official noted.

ISRO plans to launch Insat-4CR in mid-2007 as a replacement of the Insat-4C that was lost following the crash of the GSLV in July last year from the Satish Dhawan space centre at Sriharikota in Andhra Pradesh. It is set to carry 10-12 Ku-band transponders.

As the 175th launch of the European Space Agency's (ESA) Ariane programme and 31st launch of Ariane-5, the latest launch vehicle is also carrying Skynet-5A, a military secured communications satellite built by the Paris-based EADS Astrium.

The satellite, which weighs 3,025 kg, will last 12 years. Built by the ISRO Satellite Centre, Bangalore, it has been provided transponders by the Space Applications Centre, Ahmedabad. The Liquid Propulsion Systems Centre contributed the liquid apogee motors.

Skynet-5A, a communication satellite built by EADS Astrium, is its co-passenger on board the launch vehicle.

Eighteen INSATs have been launched so far, beginning with INSAT-1A from the U.S. on April 10, 1982. The last one, INSAT-4A, was launched by an Ariane vehicle from Kourou on December 22, 2005. Three INSATs — Kalpana, GSAT-2 and Edusat — were launched from Sriharikota using ISRO-built rockets.

The INSATs have brought about a communication revolution in India, enabling people living in far-flung areas to talk to each other over phone.

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