Insat-3B epitomises resilient trait of Indian scientists — SAC

With ISRO Satellite Centre (ISAC) as the lead centre, INSAT-3B has been realised with major contributions from Space Application Centre, Liquid Propulsion System Centre (LPSC), Vikram Sarabhai Space Centre (VSSC), ISRO Inertial Systems Unit (IISU), besides several industries in both public and private sector.

Gopalan said INSAT-3B is planned to cater to the increased need for transponder capacity in the INSAT system and for innovative use of satellite capacity for improved business communication, developmental and mobile communication.

He said Ariane-5 with place INSAT-3B in an elliptical orbit with apogee height of 35,865 km and perigee height of 560 km with an inclination of seven degrees. With three long-duration firings of the indigenously built Liquid Apogee Motor (LAM), the satellite is placed in the final geostationary orbit at a height of 35,800 km in the equatorial plane.

The Ariane 505 launch vehicle rolled into the launch pad at the Guyana Space Centre on Monday night, an ISRO official told newspersons.

INSAT-3B, along with its co-passenger Asia Star, a US radio broadcast satellite, has been integrated with the Ariane rocket which is scheduled to take off at 0427 IST.

The 2,070-kg INSAT-3B is sitting inside a specially-designed cone-shaped "Speltra" structure above Ariane’s upper stage. Mounted atop the Speltra is Asia star which will be the first to separate from the rocket 28 minutes after the take-off. INSAT-3B will separate next, during the 35th minute.

Filling of the cryogenic fuels – liquid hydrogen and liquid oxygen – will begin five hours before launch – about half-an-hour before midnight on Tuesday, the official said.

The launch window – time during which the rocket will blast off – has been fixed between 0427 and 0514 hours IST. The launch-readiness review for the 128th launch of Ariane with INSAT-3B and Asia Star was completed last week.

The INSAT-3B has undergone extensive tests after it was integrated with the Ariane-505 vehicle and all the systems are functioning normally, the official said.

This will be the second commercial flight of the new Ariane-5 rocket.

The Master Control Facility at Hasan in Karnataka will take control of the satellite in about 35 minutes after Ariane’s lift-off. The satellite will be co-located at 83 east longitude over the Indian Ocean along with INSAT-2E that was launched less than a year ago.

INSAT-3B, the first of the five satellites to be launched under the INSAT-3 series, carries 12 extended C-band, 3 KU-band and one S-band mobile satellite service payloads, and has a design life of 10 years.

Primarily intended for business, developmental and mobile communications, INSAT-3B’s launch had been advanced to precede that of INSAT-3A to cater to the immediate requirement of extended C-band capacity that was depleted due to the failure of INSAT-2D in 1997.

A special feature of the INSAT-3 series is an indigenously developed titanium propellant tank that was until now being imported from Germany.

Once commissioned, the satellite is expected to give a boost to the Very Small Aperture Terminal (VSAT) services.

At present, seven transponders from INSAT-2B and INSAT-2C were being used for these applications and INSAT-3B would almost double the transponder capacity for these services. For the first time, the officials said, KU-band frequencies would also be used for VSAT services, which will enable use of smaller ground terminals.

INSAT-3B would also be used to provide the first set of transponders for `Swaran Jayanti Vidya Vikas Antariksh Upagraha Yojana’ (Vidya Vahini), announced by the Prime Minister on August 15, 1998. According to ISRO, these transponders will be used exclusively for interactive training and developmental communication. Telemedicine was also expected to be introduced to help remote diagnostics and extension of super-special hospital treatment to the rural population.